HoldsUp

Huberman Lab · 2026-02-16 · Andrew Huberman (host), Lauren Colenso-Semple

The Most Effective Weight Training, Cardio & Nutrition for Women | Dr. Lauren Colenso-Semple

61 research-tied claims examined: 3 contradicted 3 overstated 2 context 50 supported 3 unverified

3 Contradicted by research
1:08:44Lauren Colenso-Semplecontradictedmoderate

The menopause transition in and of itself does not accelerate the loss of lean muscle mass.

"We see age-related muscle loss that is exacerbated by physical inactivity. But you look at lean mass across the men the across the menopause transition and that in and of itself isn't accelerating the loss of of muscle." (said at 1:08:44)

Major prospective cohort studies tracking body composition across midlife demonstrate that the menopause transition itself is independently associated with an onset and acceleration of lean mass loss, distinct from chronological aging. In the multi-ethnic Study of Women's Health Across the Nation (SWAN; PMID: 30843880), piece-wise linear modeling showed that lean mass increased or remained stable prior to the menopause transition, began a significant decline at the transition's onset that persisted until two years post-final menstrual period (FMP), and then plateaued, confirming that accelerated loss of lean mass is a menopause-related phenomenon. Other longitudinal cohorts (e.g., the ERMA study, PMID: 32456169; Hong Kong Perimenopausal Women Osteoporosis Study, PMID: 20195288) similarly show independent declines in appendicular lean mass and muscle cross-sectional area directly associated with menopausal transition stages after adjusting for age and physical activity.

1:42:20Lauren Colenso-Semplecontradictedhigh

Human research on the cognitive benefits of creatine supplementation has primarily been conducted in deficit or clinical populations such as Alzheimer's disease, SSRI-treated clinical depression, traumatic brain injury, or severe sleep deprivation.

"And the claims about brain health, I think, are premature because the data that we have to date are people in some kind of a deficit. So they were Alzheimer's patients. They were clinically depressed and also taking SSRIs. They were undergoing extreme sleep deprivation. They had a traumatic brain injury." (said at 1:42:20)

The speaker's claim that cognitive research on creatine has only or primarily evaluated individuals in deficit states (such as Alzheimer's disease, SSRI-treated clinical depression, severe sleep deprivation, or traumatic brain injury) is contradicted by the literature. Multiple systematic reviews and meta-analyses of randomized controlled trials demonstrate that numerous studies have evaluated oral creatine supplementation in healthy, non-deficit populations, including healthy young adults and older adults under normal baseline conditions, finding modest improvements in domains such as memory and processing speed.

1:41:57Lauren Colenso-Semplecontradictedmoderate

Creatine supplementation in the absence of an exercise stimulus does not increase muscle mass.

"And if you're not exercising, I really wouldn't bother taking creatine. It's not going to just increase muscle mass when you don't have the stimulus for muscle growth." (said at 1:41:57)

Randomized controlled trial evidence demonstrates that creatine supplementation without exercise training can increase lean tissue mass and strength in sedentary individuals. Furthermore, creatine confers benefits beyond muscle hypertrophy—such as cognitive and metabolic improvements—contradicting the assertion that it is pointless to take without an exercise stimulus.

3 Overstated
1:02:54Andrew Huberman (host)overstatedlow

The Environmental Working Group has reported that over 122 million Americans drink tap water containing high levels of chemicals known to cause cancer.

"The Environmental Working Group has also shown that over 122 million Americans drink tap water with high levels of chemicals known to cause cancer." (said at 1:02:54)

The Environmental Working Group (EWG) has published multiple reports and peer-reviewed risk analyses (e.g., using their Tap Water Database and UCMR datasets) modeling cumulative cancer risks for tens to hundreds of millions of Americans exposed to trace contaminants like disinfection byproducts, arsenic, nitrates, and PFAS. However, describing these as 'high levels' is an overstatement. The vast majority of municipal tap water in the United States complies with federal Maximum Contaminant Levels (MCLs) established under the Safe Drinking Water Act. EWG calculates risk exceeding thresholds based on its own non-enforceable 'health guidelines' (often modeled on a 1-in-1,000,000 lifetime excess cancer risk), which are orders of magnitude lower than federal regulatory standards, not concentrations typically characterized toxicologically as 'high'.

1:34:45Andrew Huberman (host)overstatedmoderate

Ninety percent of adults in the world consume caffeine daily.

"90% of adults in the world drink caffeine every day." (said at 1:34:45)

While caffeine is recognized as the most widely consumed psychoactive substance globally, epidemiological surveys and reviews estimate that approximately 80% of the global population consumes caffeine daily. Figures of 85% to 90% daily consumption specifically describe adults in North America and the United States rather than the worldwide adult population.

1:53:20Andrew Huberman (host)overstatedmoderate

A resistance training session lasting 30 to 60 minutes triples or quadruples circulating cortisol levels.

"As you and I both know, a good solid resistance training session of about, you know, 30 minutes to an hour will triple or quadruple circulating cortisol levels." (said at 1:53:20)

While acute resistance training can stimulate the hypothalamic-pituitary-adrenal axis and increase circulating cortisol concentrations, claiming that a typical 30- to 60-minute session routinely triples or quadruples (3- to 4-fold increase) cortisol levels is an overstatement. The magnitude of acute cortisol elevation depends heavily on exercise volume, intensity, muscle mass involved, and rest intervals. Moderate to high volume protocols with short rest intervals typically produce modest to moderate transient increases (e.g., 20% to ~100% above baseline), and standard resistance exercise often fails to elicit significant cortisol elevations or produces responses well below a 3- to 4-fold surge unless extreme, high-stress exhaustion protocols are used.

2 Needs context
0:09:00Andrew Huberman (host)needs contextmoderate

Human body temperature must increase by approximately 1 to 3 degrees Fahrenheit to wake up feeling energized.

"And in order to wake up feeling refreshed and energized, your body temperature actually has to increase by about 1 to 3°." (said at 0:09:00)

The claim accurately reflects the general physiological direction and approximate magnitude of the circadian core body temperature (CBT) rhythm, but oversimplifies the mechanism of waking alertness. Endogenous core body temperature reaches its minimum (nadir) in the second half of the biological night (typically 2–3 hours before habitual wake time) and rises by approximately 0.5 °C to 1.0 °C (~1 to 2 °F) heading into the morning and daytime peak. This temperature increase aligns with circadian alertness and metabolic activation. However, waking up feeling refreshed and energized is driven by an interaction of multiple factors (including dissipation of homeostatic sleep pressure, the cortisol awakening response, and sleep architecture), rather than solely a threshold rise of 1 to 3 degrees.

1:44:40Lauren Colenso-Sempleneeds contextmoderate

Creatine monohydrate absorption and physiological efficacy are identical whether completely dissolved in liquid or ingested as dry powder with water.

"So even if you were to just dry scoop creatine and just chase it with water, the results are the same as if you blend it up until there's literally no bits left in the glass." (said at 1:44:40)

Pharmacokinetic data show that creatine ingested as a solid form or crystalline suspension in cold water is readily absorbed, but it is not pharmacokinetically identical to fully dissolved creatine in solution. In a randomized crossover study (PMID: 11811571), solid ingestion resulted in a 20% lower peak plasma concentration (Cmax) and a 30% to 35% lower area under the curve (AUC) over 6 hours compared to the same dose in fully dissolved solution, although it still elevated plasma creatine levels 5- to 6-fold.

50 Supported by research
0:03:10Lauren Colenso-Semplesupportedhigh

Men and women exhibit very similar muscle protein synthesis and relative growth responses to exercise and nutrition.

"When we look at how the muscle responds, so we look at muscle protein synthesis in response to exercise or nutrition, there are no differences. Very similar protein metabolism response, very similar growth response." (said at 0:03:10)

The speaker's statement that men and women exhibit very similar muscle protein synthesis and relative growth responses to resistance exercise and nutrition is supported by the scientific literature. Systematic reviews and meta-analyses examining sex differences in response to resistance training demonstrate that relative muscle hypertrophy gains do not significantly differ between males and females when following the same resistance training protocols.

0:03:30Lauren Colenso-Semplesupportedhigh

Untrained adult men have higher baseline muscle mass than untrained adult women due to pubertal testosterone, but both sexes gain similar relative muscle size from resistance training.

"So if you take an untrained adult man and an untrained adult woman, there will be a disparity in their baseline muscle mass and that is due to differences in testosterone. However, once they start training, they will gain similar relative size." (said at 0:03:30)

Systematic reviews and meta-analyses consistently demonstrate that while adult males have higher baseline muscle mass and greater absolute increases in muscle size, relative gains in muscle hypertrophy following resistance training are similar between men and women.

0:04:44Lauren Colenso-Semplesupportedmoderate

Within the physiological normal reference range of testosterone, an individual's baseline testosterone level does not predict their hypertrophic response to resistance training.

"We don't see this relationship between, 'Oh, you know, you're closer to 900 and you are going to respond better to resistance training.' So as long as you're within what that wide normal range, there doesn't seem to be a predictability of your response to training." (said at 0:04:44)

Clinical exercise physiology studies demonstrate that within the physiological normal range, basal (pre-training or pre-exercise) and post-exercise systemic testosterone concentrations do not predict individual hypertrophic responses (changes in lean body mass or muscle fiber cross-sectional area) to resistance training in healthy individuals. Morton et al. (2018) examined resistance-trained young men across 12 weeks of resistance training and found that neither circulating testosterone, free testosterone, nor any other measured systemic hormone correlated with or predicted hypertrophy; rather, intramuscular androgen receptor content accounted for individual variability.

0:08:45Andrew Huberman (host)supportedmoderate

Human core body temperature must decrease by approximately 1 to 3 degrees Fahrenheit to fall asleep and maintain deep sleep.

"And that's because in order to fall asleep and stay deeply asleep, your body temperature actually has to drop by about 1 to 3°." (said at 0:08:45)

Human thermoregulation and sleep propensity are intimately coupled through circadian and homeostatic mechanisms. Across the circadian cycle, human core body temperature (CBT) fluctuates by approximately 0.5°C to 1°C (roughly 1°F to 2°F, up to ~3°F peak-to-trough), with the steepest rate of core temperature decline occurring immediately prior to and during sleep onset. Peripheral vasodilation dissipates heat to cool the core and brain, which facilitates sleep initiation and entry into deep (non-rapid eye movement / slow-wave) sleep.

0:11:53Lauren Colenso-Semplesupportedhigh

Standard clinical hormone assays used historically have lacked the sensitivity to accurately detect normal low circulating testosterone levels in women.

"the way testosterone has been measured in women for a very long time is such that the assays are not capable of detecting some of these normal low levels." (said at 0:11:53)

Standard clinical immunoassays historically used to measure total testosterone were designed primarily for male reference ranges and have well-documented limitations in analytical sensitivity and specificity at the lower testosterone concentrations typical in women and children. Due to cross-reactivity and poor functional sensitivity at low concentrations, direct immunoassays often produce inaccurate or imprecise results in female reference ranges, leading major endocrine societies and standardisation bodies (such as the CDC Hormone Standardization Program) to recommend extraction techniques or liquid chromatography-tandem mass spectrometry (LC-MS/MS) for accurate measurement in women.

0:12:15Lauren Colenso-Semplesupportedhigh

Acute, transient post-exercise elevations in systemic testosterone and growth hormone do not drive long-term muscle hypertrophy.

"that acute response to exercise, that increase in post-exercise testosterone, growth hormone, etc., people used to think that was the driver of hypertrophy... But what we know now is that response, although acutely there, is not the driver of growth long term." (said at 0:12:15)

Multiple prospective resistance training trials and mechanistic reviews demonstrate that transient post-exercise elevations in systemic anabolic hormones (such as testosterone and growth hormone) do not correlate with or drive long-term skeletal muscle hypertrophy. Instead, muscle growth is primarily regulated by intrinsic intramuscular signaling pathways (e.g., mechanotransduction, p70S6K activation, and androgen receptor expression) and local protein synthetic responses.

0:15:15Lauren Colenso-Semplesupportedhigh

Incorporating resistance training alongside sport-specific training in female teenage athletes improves performance and reduces injury risk.

"there can be not only a performance improvement, but also an injury reduction from doing some resistance training along with your sport-specific training." (said at 0:15:15)

Extensive randomized controlled trial and meta-analytic evidence supports the claim that integrating resistance and neuromuscular training alongside regular sports practice reduces injury risk (particularly ACL injuries and ankle sprains) and enhances athletic performance (such as jump height, sprint speed, and change of direction) in female adolescent athletes.

0:15:40Lauren Colenso-Semplesupportedhigh

Older adults starting resistance training at age 70 are capable of gaining new muscle mass.

"That said, we know that you can gain muscle anytime, even if you start at 70." (said at 0:15:40)

Substantial randomized controlled trial evidence and meta-analyses show that older adults, including those beginning resistance training in their 70s and beyond, retain muscle plasticity and can successfully increase muscle mass (lean body mass) and muscular strength.

0:26:52Lauren Colenso-Semplesupportedmoderate

Pairing opposing muscle groups in agonist-antagonist supersets does not impair acute performance or chronic hypertrophic adaptations compared to traditional straight sets.

"So when you look at somebody doing a bench press or chest press and then instead of resting for the two to three minutes and then doing the next set, they go and they do a row. And so you're going back and forth and you're you're pairing a push and a pull. And that doesn't seem to interfere with adaptation or even acute performance the same way it would if you didn't rest in between your straight sets of bench press." (said at 0:26:52)

A systematic review and meta-analysis comparing superset resistance training with traditional straight-set training found that supersets (and specifically agonist-antagonist paired sets) reduce session duration without compromising acute training volume, repetition performance, muscle activation, or chronic adaptations in muscle hypertrophy (SMD = -0.05, p = 0.87) and maximal strength. Subgroup analysis specifically showed that agonist-antagonist supersets maintained or even increased total completed repetitions compared to traditional sets.

0:08:18Andrew Huberman (host)supportedmoderate

Red light, near-infrared, and infrared light therapy promote faster muscle recovery, improve skin health and acne, accelerate wound healing, reduce pain and inflammation, enhance mitochondrial function, and improve vision.

"red light, near infrared, and infrared light have been specifically shown to have positive effects on improving numerous aspects of cellular and organ health. These include faster muscle recovery, improved skin health, wound healing, improvements in acne, reduced pain and inflammation, improved mitochondrial function, and even improvements in vision." (said at 0:08:18)

Photobiomodulation (PBM) using red and near-infrared light (typically 600–1100 nm) has been shown across numerous preclinical and clinical studies to exert beneficial effects on mitochondrial function (principally by targeting cytochrome c oxidase and increasing ATP production), muscle recovery (reducing delayed-onset muscle soreness and accelerating functional recovery), wound healing and tissue regeneration, inflammation and pain reduction, dermatological conditions (including acne and skin rejuvenation), and visual function (such as in age-related macular degeneration and myopia). While optimal dosing parameters and protocols vary across clinical applications, the broad spectrum of benefits described by the speaker is well-documented in the scientific literature.

0:35:13Lauren Colenso-Semplesupportedhigh

To maximize one-rep max strength, an individual must train with very high-load and very low-repetition ranges.

"Certainly if you're training for maximal strength, i.e., a one-rep max, then you need to be training in in those lower rep ranges because that is a sport-specific uh training. And so it's not that if you do sets of 10, your one-rep max won't get stronger. It will, but to maximize your one-rep max, then we need to do some very high-load, very low-rep training." (said at 0:35:13)

Multiple systematic reviews and meta-analyses of randomized trials demonstrate that while lower-load resistance training also increases 1RM strength, high-load/low-repetition resistance training (typically ≥80% 1RM or ≤7 repetitions) leads to significantly greater dynamic maximal strength (1RM) gains than moderate- or low-load protocols.

0:36:07Lauren Colenso-Semplesupportedhigh

Similar muscle hypertrophy occurs whether training with high-load, low-rep ranges or lower-load, high-rep ranges, provided sets are performed close enough to failure.

"If the goal is hypertrophy, we have way more flexibility because we do see similar growth whether you're training in those high-load, low-rep ranges or the lower-load, high-rep ranges and anything in between, provided that we train close enough to failure." (said at 0:36:07)

Meta-analytic evidence confirms that muscle hypertrophy is similar across a wide spectrum of loading zones (low-load, high-rep vs. high-load, low-rep resistance training) when sets are performed to or close to momentary muscular failure. A systematic review and meta-analysis of 21 randomized trials by Schoenfeld et al. (2017) found no significant difference in muscle hypertrophy between low-load (<=60% 1RM) and high-load (>60% 1RM) protocols when sets were taken to failure, even though high loads produced superior 1RM strength gains.

0:45:22Lauren Colenso-Semplesupportedhigh

A true interference effect blunting hypertrophic adaptations between endurance training and resistance training occurs primarily when performing high training volumes stacked close together.

"We see that could be true if you're doing very high volume work and you're stacking it very close together. So assuming your hypertrophy or strength is the goal, then we would want to perform that first and if possible, separate them by, you know, at least several hours. But we really don't run into true uh interference effect type results unless we're doing tons of training" (said at 0:45:22)

Meta-analyses of randomized and controlled trials confirm that concurrent aerobic and resistance training generally does not attenuate whole-muscle hypertrophy compared to resistance training alone under typical training volumes (SMD -0.01, 95% CI -0.16 to 0.18). Interference effects on muscular adaptations become pronounced primarily with high endurance training volumes (higher duration and frequency) and when sessions are completed in close temporal proximity without adequate recovery between bouts.

0:48:58Lauren Colenso-Semplesupportedmoderate

For completely inactive individuals, increasing daily step count up to 4,000, 5,000, or 6,000 steps provides significant health benefits.

"So I think somebody who isn't active at all going from doing very few steps to getting it up to four, five, 6,000 steps, yes, we're going to see a huge benefit." (said at 0:48:58)

Extensive meta-analyses of prospective cohort studies consistently demonstrate that for inactive or low-activity individuals, increasing daily step count to 4,000–6,000 steps is associated with substantial, statistically significant reductions in all-cause and cardiovascular mortality. A meta-analysis of 15 international cohorts (Paluch et al., 2022) found that moving from the lowest quartile (median ~3,553 steps/day) to the second quartile (median ~5,801 steps/day) was associated with a 40% reduction in all-cause mortality (HR 0.60, 95% CI 0.51–0.71). Another meta-analysis of 17 cohorts (Banach et al., 2023) identified significant mortality benefits emerging around ~3,867 steps/day (and ~2,337 steps/day for CV mortality), with every 1,000-step increment conferring a 15% reduction in all-cause mortality.

0:50:29Lauren Colenso-Semplesupportedhigh

Fat loss resulting from adding exercise alone is relatively small compared to the fat loss achieved through dietary modifications.

"the fat loss that we will get from just adding exercise is pretty disappointing relative to the fat loss that we will see when we adjust our nutrition." (said at 0:50:29)

The claim accurately reflects findings from systematic reviews and meta-analyses of randomized controlled trials comparing dietary modification, exercise training, and their combination. Dietary calorie restriction consistently produces substantially larger reductions in body weight and fat mass than exercise alone, while adding exercise to dietary changes provides a modest additional benefit for total fat loss and the preservation of lean tissue.

0:52:00Lauren Colenso-Semplesupportedhigh

Cardiovascular and endurance adaptations can be achieved in less time by doing higher-intensity exercise compared to longer-duration moderate-intensity exercise.

"So, if we look at those adaptations to endurance exercise or if we're going to just say cardio broadly, then you can get those by doing more long form moderate intensity. You can also get those by doing higher intensity for shorter amounts of time. So, it's not that it's magic in terms of the adaptation, but you're able to get more bang for your buck because you're doing that higher intensity and you don't need to do it for quite as long." (said at 0:52:00)

Extensive randomized trial evidence and systematic reviews confirm that high-intensity interval training (HIIT) and sprint interval training (SIT) produce similar improvements in cardiorespiratory fitness (VO2max), skeletal muscle mitochondrial capacity, and cardiometabolic health markers compared to moderate-intensity continuous training (MICT), while requiring substantially less total exercise time.

0:53:03Lauren Colenso-Semplesupportedmoderate

Scientific data does not support the claim that women need to alter their exercise programming based on hormonal fluctuations across the menstrual cycle.

"The unfortunate shift of because you have a menstrual cycle and because hormones are fluctuating, you need to change how you are exercising is way too simplistic and doesn't align with the data that we have." (said at 0:53:03)

Systematic reviews and meta-analyses consistently show that fluctuations in sex hormones across the menstrual cycle exert trivial or clinically negligible effects on exercise performance, substrate oxidation, and chronic training adaptations (such as muscle hypertrophy and strength gains). Meta-analyses indicate that uniform recommendations or periodized programming based strictly on menstrual cycle phases are not supported by the scientific literature, and that any adjustments should instead be individual- and symptom-driven rather than phase-prescriptive.

1:01:21Lauren Colenso-Semplesupportedmoderate

Survey data shows that 75% to 80% of women report experiencing menstrual symptoms such as cramps, low back pain, lack of motivation, and irritability.

"We have survey data looking at how many people report experiencing menstrual symptoms, things like uh cramps and low back pain, uh lack of motivation, irritability. And 75-80% of women report feeling those symptoms." (said at 1:01:21)

Large population survey data consistently align with the speaker's claim. In a nationwide cross-sectional survey of 42,879 women (PMID: 30885768), dysmenorrhea (cramps/pain) was reported by 85% of respondents and psychological complaints (such as irritability/mood symptoms) by 77%, directly reflecting the 75% to 80% range cited by the speaker.

1:02:27Andrew Huberman (host)supportedmoderate

A 2020 study by the Environmental Working Group estimated that more than 200 million Americans are exposed to PFAS chemicals through tap water.

"In fact, a 2020 study by the Environmental Working Group estimated that more than 200 million Americans are exposed to PFAS chemicals, also known as forever chemicals, through drinking of tap water." (said at 1:02:27)

A 2020 study published by scientists from the Environmental Working Group (Andrews & Naidenko, Environmental Science & Technology Letters) evaluated publicly available data on PFAS occurrence in drinking water across the United States. The authors estimated that over 200 million Americans likely receive tap water containing perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) at concentrations of 1 ng/L or greater.

1:02:42Andrew Huberman (host)supportedmoderate

PFAS chemicals are linked to health issues including hormone disruption, gut microbiome disruption, and fertility issues.

"These forever chemicals are linked to serious health issues such as hormone disruption, gut microbiome disruption, fertility issues, and many other health problems." (said at 1:02:42)

Published systematic reviews and epidemiological/toxicological studies support the assertion that per- and polyfluoroalkyl substances (PFAS) are associated with endocrine/hormone disruption, reduced fertility (and related reproductive disorders such as earlier menopause and polycystic ovarian syndrome), and alterations in gut microbiome composition.

1:04:24Lauren Colenso-Semplesupportedmoderate

Combined oral contraceptive pills do not significantly alter exercise-induced adaptations in strength, hypertrophy, or power.

"there is enough data at this point to say when it comes to strength, hypertrophy, power, we're not seeing combined oral contraceptive pills move the needle in either direction." (said at 1:04:24)

A 2024 systematic review and multilevel meta-analysis specifically evaluated the effect of oral contraceptive pill (OCP) use on skeletal muscle adaptations to resistance exercise training across 8 experimental studies (325 participants). The meta-analysis found no statistically significant difference between OCP users and non-users in hypertrophy (p = 0.90), power (p = 0.80), or strength (p = 0.20), supporting the speaker's claim that oral contraceptives do not meaningfully alter these training adaptations in either direction.

1:07:02Lauren Colenso-Semplesupportedmoderate

The downregulation of endogenous hormones caused by hormonal contraceptives does not impact exercise performance or training adaptations.

"in terms of just the hormones themselves and the fact that, you know, we're downregulating the endogenous hormone production by introducing these synthetic hormones, that doesn't seem to impact performance or adaptations to exercise." (said at 1:07:02)

Systematic reviews and meta-analyses show that the suppression of endogenous sex hormones resulting from oral hormonal contraceptive use does not significantly impair or alter chronic exercise adaptations (such as muscle hypertrophy, power, and strength) and has only trivial, non-meaningful effects on acute exercise performance. A 2024 multilevel meta-analysis found no significant difference between oral contraceptive users and non-users in hypertrophy (p = 0.90), power (p = 0.80), or strength (p = 0.20) gains following resistance training. Similarly, a 2020 meta-analysis evaluating acute exercise performance found group-level differences between users and naturally menstruating women to be trivial, with performance remaining consistent across active and withdrawal pill phases.

1:12:15Lauren Colenso-Semplesupportedhigh

Resistance training produces adaptations in tendons and bones in addition to building muscle.

"And so when we are lifting weights, we're not exclusively building muscle. And that's why we see tendon adaptations, bone adaptations, everything is connected." (said at 1:12:15)

Resistance training induces significant physiological and structural adaptations in both tendons and bones, in addition to muscular adaptations. A systematic review and meta-analysis of 61 studies examining tendon adaptations to mechanical loading found that resistance training leads to substantial increases in tendon stiffness, elastic modulus, and cross-sectional area. Similarly, meta-analyses of randomized trials confirm that resistance training interventions reliably preserve and increase bone mineral density (BMD) across anatomical sites, including the lumbar spine and femoral neck.

1:16:12Lauren Colenso-Semplesupportedmoderate

Physical activity can help alleviate menstrual symptoms such as cramps by increasing blood flow.

"Not with resistance training specifically, but with physical activity, sure. Uh it it it can definitely help. Um because you if you have something like cramps, then just kind of doing something to increase blood flow, even if it's going for a walk, can be helpful." (said at 1:16:12)

Multiple systematic reviews and meta-analyses of randomized controlled trials demonstrate that physical activity and aerobic exercise (including low-intensity activities) significantly reduce menstrual pain intensity and duration in individuals with primary dysmenorrhea. While the exact mechanistic contribution of pelvic blood flow compared to hormonal, neurochemical (endorphin release), or anti-inflammatory pathways continues to be investigated, the core claim that general physical activity like walking helps alleviate menstrual cramps is well supported.

1:16:54Lauren Colenso-Semplesupportedmoderate

There is no scientific data supporting the practice of adjusting caloric, protein, or carbohydrate intake based on the phases of the menstrual cycle.

"Does that mean that you should change caloric intake or protein intake or carbohydrate intake? We don't have the data to support any of that." (said at 1:16:54)

Scientific reviews and position statements note that despite small physiological variations in substrate metabolism across the menstrual cycle (such as during the luteal phase), there is a lack of rigorous, outcome-based clinical evidence to justify routinely altering caloric, carbohydrate, or protein intake based on menstrual cycle phase. As summarized in a dedicated review on fuelling female athletes (PMID: 34015236), it is 'premature to conclude that female athletes require sex specific guidelines in relation to CHO or protein requirements provided energy needs are met.' Systematic reviews also confirm that scientific studies establishing phase-specific nutritional manipulations are scarce (PMID: 38994896).

1:21:07Lauren Colenso-Semplesupportedmoderate

Performing two 20-minute full-body resistance training sessions per week is sufficient to significantly attenuate age-related muscle loss and reduce fall and fracture risk.

"All we need is two 20-minute workouts per week, full body resistance training, to make a pretty powerful impact on trying to attenuate some of that decline and losing muscle mass, increasing fall risk, fracture risk, all of those downstream health effects" (said at 1:21:07)

Resistance training guidelines (such as those from the ACSM and WHO) and systematic reviews indicate that two weekly full-body resistance training sessions are sufficient to elicit meaningful gains in muscular strength and hypertrophy, helping attenuate age-related sarcopenia and associated functional decline. A meta-regression of older adults (PMID 32948100) demonstrated that muscle hypertrophy adaptations do not differ significantly between 2 versus >2 days per week, supporting the premise that two weekly sessions are effective.

1:27:31Lauren Colenso-Semplesupportedhigh

The constitutional body type categories ectomorph, endomorph, and mesomorph originated in psychology rather than physiology.

"I could be wrong, but I think those labels and those descriptors don't even come from any sort of physiology uh research or framework. I think they come from psychology, which makes no sense given that we're using them to describe how one might expect to adapt to training." (said at 1:27:31)

The claim is accurate. The somatotype categories of ectomorph, mesomorph, and endomorph were developed in the 1940s by American psychologist William Herbert Sheldon as part of his framework of 'constitutional psychology' (the constitutional theory of personality), which attempted to link physical body morphology to personality traits, temperament, and behavioural tendencies rather than exercise physiology or training adaptation.

1:29:55Andrew Huberman (host)supportedmoderate

N-acetylcysteine (NAC) supplementation and eating leafy greens support glutathione production and bodily detoxification.

"while also making an effort to eat more leafy greens and supplementing with NAC, N-acetylcysteine, both of which can support glutathione production and detoxification." (said at 1:29:55)

The claim accurately reflects established biochemical and nutritional mechanisms. N-acetylcysteine (NAC) serves as a direct precursor to cysteine, the rate-limiting substrate for glutathione (GSH) synthesis, and is routinely used clinically to replenish intracellular glutathione pools and facilitate xenobiotic detoxification (such as in acetaminophen-induced toxicity). Leafy and cruciferous greens supply sulfur-containing compounds and isothiocyanates (such as sulforaphane) that activate the Nrf2 pathway, inducing phase II detoxification enzymes—notably glutathione S-transferases (GST)—and supporting endogenous glutathione synthesis and detoxification.

1:31:39Lauren Colenso-Semplesupportedmoderate

Long-term adaptations in muscle growth and fat loss from exercise are the same whether training in a fed or fasted state, in both men and women.

"So in the case of of of fed and fasted state training, this has been looked at long on longer term studies. So consistent fasted state training, not just an acute bout of fasted state training. And the muscle growth and fat loss adaptations to exercise are the same in men and in women." (said at 1:31:39)

Longer-term randomized and controlled studies comparing consistent fasted versus fed exercise training demonstrate that chronic adaptations in muscle hypertrophy and fat-free mass do not significantly differ between fed and fasted conditions in both male and female cohorts. Meta-analytic evidence shows equivalent outcomes for muscle growth and similar overall body composition adaptations across training states.

1:32:19Lauren Colenso-Semplesupportedhigh

Acute fat oxidation during or immediately after exercise does not meaningfully offset 24-hour total energy metabolism to produce greater long-term body fat loss.

"Turns out that acute fat oxidation or fat oxidation post-workout isn't meaningful enough to offset the rest of the metabolism throughout the day such that you don't lose more body fat long term." (said at 1:32:19)

Whole-room indirect calorimetry studies consistently demonstrate that acute fat oxidation during or immediately after an exercise bout does not increase total 24-hour fat oxidation compared to a control day. Long-term body fat reduction is primarily determined by overall energy and macronutrient balance rather than acute intra- or post-workout substrate partitioning.

1:33:00Lauren Colenso-Semplesupportedhigh

Most resistance training sessions are not extremely glycogen depleting.

"And most resistance training sessions aren't extremely glycogen depleting anyway." (said at 1:33:00)

Evidence from systematic reviews and meta-analyses supports the statement that typical resistance training workouts do not cause extreme or complete muscle glycogen depletion. While resistance exercise causes a moderate, volume-dependent decrease in muscle glycogen (typically around 20–40% depending on the number of sets and duration), full or severe glycogen depletion is rarely observed compared to prolonged endurance exercise.

1:35:49Lauren Colenso-Semplesupportedmoderate

The macronutrient composition of a meal consumed immediately prior to a resistance training workout is unlikely to be used as fuel during that workout.

"But for resistance training, the composition of the meal you're eating pre-workout is very unlikely to be used as fuel in that workout." (said at 1:35:49)

The speaker's claim is supported by exercise physiology and sports nutrition evidence. Resistance exercise primarily relies on anaerobic energy systems, specifically intracellular phosphagens (ATP and phosphocreatine) and endogenous intramuscular glycogen, rather than circulating macronutrients from an immediate pre-workout meal. Whole-food meals take hours to digest and absorb, meaning macronutrients eaten right before resistance training remain largely in the gastrointestinal tract and do not provide the acute mechanical fuel during the workout.

1:37:21Lauren Colenso-Semplesupportedhigh

Post-resistance training elevation in muscle protein synthesis lasts for at least 24 hours.

"it turns out that post-resistance training, that window, that elevated protein synthesis is long-lasting. We've measured this and see that it's still elevated even 24 hours after your session." (said at 1:37:21)

Human tracer kinetic and muscle biopsy studies demonstrate that the elevation in muscle protein synthesis (specifically myofibrillar protein fractional synthetic rate) following an acute bout of resistance exercise is prolonged and remains significantly elevated at 24 hours and up to 48 hours post-exercise.

1:37:50Lauren Colenso-Semplesupportedhigh

Consuming dietary protein within 30 minutes versus 3 hours after a resistance training session does not alter the extent of muscle adaptation.

"this indicates that whether you're eating within 30 minutes or 3 hours, that's not going to affect the extent to which that dietary protein can support your muscle adaptations." (said at 1:37:50)

Meta-analyses of randomized controlled trials examining protein timing demonstrate that consuming protein immediately post-exercise (e.g., within 30-60 minutes) versus several hours later does not significantly affect muscle hypertrophy or strength adaptations when total daily protein intake is controlled. Total daily protein intake, rather than precise peri-workout timing within a 30-minute window, is the primary driver of chronic muscle adaptations.

1:43:02Lauren Colenso-Semplesupportedhigh

Creatine supplementation commonly causes an elevation in blood creatinine levels on laboratory tests.

"It will increase uh creatinine levels on a blood chart. Is that right? Often it will. Yes." (said at 1:43:02)

Systematic reviews and meta-analyses of randomized controlled trials confirm that creatine supplementation significantly increases serum creatinine concentrations on blood tests. Because creatinine is the non-enzymatic breakdown byproduct of creatine, higher intake and muscular stores increase circulating creatinine without indicating actual renal impairment (as verified by gold-standard direct GFR measures such as Cr-EDTA).

1:43:33Lauren Colenso-Semplesupportedhigh

Long-term studies demonstrate that taking 5 grams of creatine monohydrate per day for years is safe.

"And is it still true that the long-term data show no danger of taking creatine on the order of 5 grams per day for years? Is that still true? That's still true. It's one of the most studied supplements out there." (said at 1:43:33)

The speaker's claim that long-term data demonstrate that taking ~5 grams of creatine monohydrate per day for years is safe is well supported. The International Society of Sports Nutrition (ISSN) position stand concluded that short- and long-term supplementation (ranging up to 30 g/day for up to 5 years) is safe and well tolerated across diverse populations. Risk assessment reviews have established 5 g/day as the Observed Safe Level (OSL) for chronic consumption, and large meta-analyses across hundreds of randomized controlled trials demonstrate no increased risk of renal, hepatic, or gastrointestinal adverse events compared to placebo.

1:50:35Lauren Colenso-Semplesupportedmoderate

Acute cortisol increases from normal physiological stressors and exercise do not cause body fat storage or impede fat loss.

"And th those acute fluctuations are not contributing to fat storage or inability to lose fat." (said at 1:50:35)

The speaker's assertion that acute cortisol fluctuations from exercise and normal physiological stressors do not cause fat storage or block fat loss is supported by endocrine and exercise physiology. Acute elevations in cortisol and catecholamines during exercise and transient physiological stressors act catabolically to mobilize substrate (stimulating lipolysis and free fatty acid mobilization rather than lipogenesis/storage). Chronic hypercortisolemia (such as in Cushing's syndrome or prolonged chronic stress combined with hyperinsulinemia) can promote visceral adiposity, but transient, acute spikes do not cause fat storage or prevent fat loss.

  • supports: Interactions of metabolic hormones, adipose tissue and exercise. (Sports medicine (Auckland, N.Z.) 2005) · cited 166x in the literature
    "All of the hormones mentioned above are associated with each other and respond to exercise and exercise training. Thus, exercise is one of the major links between the hormonal modulators of energy intake and output. It appears that the sympathetic nervous system and the catecholamines are key components facilitating the lipolytic activity during exercise. These two neuroendocrine factors directly affect adipose metabolism and metabolic hormones that influence adipose metabolism. Acute low- and moderate-intensity exercise causes hormonal changes that facilitate lipolytic activity." (abstract, results, passage verified)
    pubmedfull study (doi)
1:56:00Lauren Colenso-Semplesupportedhigh

Cortisol is physiologically required for the regulation of blood pressure and blood glucose.

"It it's also necessary for blood pressure regulation, blood glucose regulation." (said at 1:56:00)

Cortisol (the primary endogenous glucocorticoid in humans) is physiologically essential for life and directly regulates both glucose metabolism and vascular tone/blood pressure. In glucose homeostasis, cortisol promotes hepatic gluconeogenesis, inhibits peripheral glucose uptake, and acts as a key counter-regulatory hormone to maintain euglycemia. In cardiovascular physiology, cortisol regulates blood pressure through permissive actions on vascular sensitivity to catecholamines, modulation of endothelial nitric oxide synthesis, and intrinsic mineralocorticoid/glucocorticoid receptor signaling.

1:59:01Lauren Colenso-Semplesupportedhigh

Cushing's syndrome is most commonly an iatrogenic condition resulting from high-dose or prolonged corticosteroid use.

"and Cushing's syndrome is not very common. It's typically you know a manifestation of somebody who's taking a lot of of steroids and then you you're ending up with this chronically elevated cortisol as a side effect." (said at 1:59:01)

Cushing's syndrome (hypercortisolism) is widely recognized in endocrine clinical practice and literature as most commonly resulting from exogenous (iatrogenic) glucocorticoid administration for various inflammatory, autoimmune, or neoplastic conditions, while endogenous causes are comparatively rare.

2:04:00Andrew Huberman (host)supportedhigh

Transitioning resistance training from the late afternoon or evening to the morning causes an initial drop in performance that resolves within a couple of weeks.

"particularly if you transition from late afternoon or evening training to morning training, you might see a kind of hit in performance initially, but that should resolve in a couple weeks." (said at 2:04:00)

The speaker's claim is supported by systematic reviews and randomized trials. Muscular strength and anaerobic performance follow a diurnal rhythm, with a natural nadir in the early morning and peak performance in the late afternoon/evening. When individuals switch to regular morning resistance training, they initially experience this lower baseline morning performance, but time-of-day-specific adaptations blunt or eliminate this diurnal deficit within several weeks of consistent morning training.

2:05:35Lauren Colenso-Semplesupportedmoderate

Estrogen-based menopausal hormone therapy is effective for symptom management, but evidence does not show that it attenuates muscle mass loss or increases muscle mass.

"And there's a wealth of data that this can be really effective for symptom management, which has a ton of downstream effects. So, we don't have good data to to suggest that it is going to attenuate the loss of muscle mass or increase muscle mass." (said at 2:05:35)

The speaker's claim is supported by high-level evidence. A 2019 systematic review and meta-analysis of 12 randomized controlled trials (4,474 postmenopausal women) published in JAMA Network Open found that hormone therapy did not significantly attenuate lean body mass loss compared with control (difference of 0.06 kg, 95% CI: -0.05 to 0.18 kg; P = .26), regardless of regimen type, dose, or duration of follow-up. Furthermore, menopausal hormone therapy remains widely established and indicated for the effective management of menopausal symptoms.

2:06:10Lauren Colenso-Semplesupportedhigh

Testosterone therapy in women is currently only scientifically proven to be effective for treating low sexual desire and low libido.

"The testosterone conversation gets a little bit trickier because right now it's really only kind of proven to be effective for low sexual desire, low libido in women." (said at 2:06:10)

The speaker's statement is accurate. Large-scale systematic reviews and meta-analyses of randomized controlled trials, as well as international clinical practice guidelines, indicate that the only evidence-based indication for testosterone therapy in women is for hypoactive sexual desire disorder (HSDD) / low sexual desire causing distress (primarily in postmenopausal women). Meta-analyses of RCT data (such as Islam et al., 2019) show significant increases in sexual desire, arousal, and satisfying sexual events, but found no significant effect or insufficient evidence for other outcomes such as cognitive measures, musculoskeletal health, body composition, mood, or general well-being.

2:06:30Lauren Colenso-Semplesupportedhigh

Testosterone supplementation above low-normal physiological levels in women can cause side effects including voice deepening and unwanted hair growth.

"And then if you start to go beyond that low normal, then we can get a lot of those unwanted side effects that we would get if we were taking testosterone for the bodybuilding purpose. And so you might see voice deepening or unwanted hair growth" (said at 2:06:30)

Clinical guidelines and reviews confirm that while testosterone dosing within physiological normal ranges carries minimal risk, supraphysiological androgen administration in women leads to dose-dependent adverse effects, including unwanted hair growth (hirsutism), acne, and virilizing effects such as voice deepening.

2:08:14Lauren Colenso-Semplesupportedhigh

Current clinical evidence does not support using menopausal hormone therapy for the prevention of cognitive decline or cardiovascular disease.

"the data to date doesn't support the use of it for preventing cognitive decline or preventing cardiovascular disease." (said at 2:08:14)

Major clinical guideline bodies and systematic reviews of randomized controlled trials (including the Women's Health Initiative and Cochrane reviews) conclude that menopausal hormone therapy does not confer net benefit for the primary prevention of chronic conditions, including cardiovascular disease and cognitive decline/dementia, and recommend against its use for disease prevention.

2:10:10Lauren Colenso-Semplesupportedhigh

Men and women exhibit very similar physiological responses to exercise training.

"The data says men and women respond to exercise very similarly." (said at 2:10:10)

Systematic reviews and meta-analyses examining adaptations to both resistance training and aerobic or high-intensity interval training (HIIT) demonstrate that men and women experience very similar relative physiological adaptations. Meta-analyses show comparable relative increases in muscle hypertrophy, lower-body strength, maximal oxygen uptake (VO2max), threshold power, and left ventricular mass/function. While absolute gains are often larger in males due to baseline differences in body size and muscle mass, relative adaptations are essentially equivalent, with females occasionally showing greater relative upper-body strength gains.

2:20:04Lauren Colenso-Semplesupportedhigh

The Women's Health Initiative stopped an estrogen-based hormone therapy trial early because it was not reducing cardiovascular risk and appeared to increase risk.

"the Women's Health Initiative was doing a set of of studies looking at hormone therapy. It was older uh versions of hormone therapy. But ultimately the the goal was to evaluate the utility of that estrogen-based hormone therapy for reduced risk of cardiovascular disease. And they stopped one of the trials early because they saw that, you know, it wasn't reducing risk and that perhaps it was going in the other direction" (said at 2:20:04)

The Women's Health Initiative (WHI) randomized controlled trials were designed to test postmenopausal hormone therapy regimens for the primary prevention of chronic disease, with coronary heart disease (CHD) designated as the primary efficacy endpoint. Both arms of the WHI trial were terminated early. In 2002, the estrogen-plus-progestin trial was halted after a mean follow-up of 5.2 years because overall risks exceeded benefits, showing an increased risk of CHD (HR 1.29), stroke (HR 1.41), pulmonary embolism (HR 2.13), and invasive breast cancer. In 2004, the estrogen-alone trial was also halted early after an average of 6.8 years because conjugated equine estrogens did not reduce CHD incidence (HR 0.91, 95% CI 0.75-1.12) and significantly increased the risk of stroke (HR 1.39).

2:03:38Lauren Colenso-Semplesupportedmoderate

Walking with a weighted vest does not provide an adequate stimulus to improve muscle mass or bone density.

"And so walking with a weighted vest is not going to improve muscle or bone. It's not the appropriate stimulus." (said at 2:03:38)

The speaker's claim is supported by clinical trial and meta-analytic evidence. Muscle hypertrophy and meaningful osteogenesis require high mechanical strain, high-intensity loading, or progressive resistance training. In randomized trials and meta-analyses, adding a weighted vest to walking or daily activity fails to produce significant muscle hypertrophy or additive bone mineral density (BMD) improvements beyond exercise alone. In the 12-month INVEST randomized trial (PMID 40540267, PMID 41761582), wearing a weighted vest for ~7 hours daily did not mitigate hip bone loss or improve muscle cross-sectional area compared to weight loss alone, whereas progressive resistance training preserved muscle. A 2026 systematic review and meta-analysis (PMID 42601514) also concluded that adding a weighted vest to existing exercise provided no significant additive benefit to bone mineral density.

2:04:15Lauren Colenso-Semplesupportedmoderate

Grip strength serves as a clinical proxy for overall body strength and is correlated with longevity.

"So we know there's a relationship between grip strength and, you know, quote unquote longevity because grip grip strength is a proxy for overall strength." (said at 2:04:15)

Large systematic reviews and meta-analyses of prospective cohort studies consistently demonstrate that handgrip strength is an established biomarker/proxy of overall muscular strength and is inversely associated with all-cause and cardiovascular mortality (i.e., positively correlated with longevity). For example, a meta-analysis of 42 studies comprising over 3 million individuals found a 16% increase in all-cause mortality risk per 5-kg decrease in grip strength.

2:05:18Lauren Colenso-Semplesupportedmoderate

Abdominal exercises do not cause localized fat loss or spot reduction of belly fat.

"Any kind of abdominal exercise is not going to burn off your belly fat." (said at 2:05:18)

Randomized controlled trials demonstrate that isolated abdominal exercise training improves core muscular endurance and strength but does not significantly reduce abdominal subcutaneous fat, android fat percentage, or waist circumference in the absence of overall caloric deficit and systemic fat loss.

2:06:40Lauren Colenso-Semplesupportedmoderate

Using cold-water immersion ice baths or NSAIDs after resistance training can blunt muscle hypertrophy adaptations by reducing inflammatory signaling.

"If you want to accelerate recovery, then you're potentially compromising adaptation. So, ice baths are a perfect example of that. You know, you're getting more recovery, but you're possibly blunting the hypertrophic stimulus. So, same with NSAIDs. HOST: Same with NSAIDs. Yeah. Um, they will block hypertrophy because they reduce inflammation, GUEST1: Right. Right." (said at 2:06:40)

The claim is supported by randomized controlled trials in humans. Regular post-exercise cold-water immersion has been demonstrated to blunt anabolic signaling pathways (such as p70S6K / mTORC1), satellite cell activity, and long-term gains in muscle fiber cross-sectional area and overall muscle volume following resistance training. Similarly, high-dose NSAID ingestion (e.g., ibuprofen at 1,200 mg/day) has been shown to blunt resistance training-induced muscle hypertrophy in young adults, accompanied by suppression of inflammatory signaling markers such as intramuscular IL-6 expression.

3 No source found (not proven false)
1:01:43Lauren Colenso-Sempleunverifiedlow

Survey data shows that women typically do not report overhauling or changing their training in response to menstrual symptoms.

"And none of them report changing their training in response to those symptoms. So, and not to say that you shouldn't, but typically, at least where the data shows, it's not that common that people are overhauling their training even in response to menstrual symptoms." (said at 1:01:43)

A definitive evaluation of the claim could not be completed within the search query limit because full abstract records detailing survey responses on training modifications could not be fetched. While broad survey studies in exercising women examine menstrual symptom prevalence and training availability, specific published survey data verifying that women typically do not modify or overhaul their training could not be confirmed.

1:40:58Lauren Colenso-Sempleunverifiedvery low

Chemical analysis of top-selling creatine gummy brands on Amazon revealed that some products contained virtually no creatine.

"Uh, someone actually analyzed a bunch of creatine gummies, top selling brands on Amazon, and some of them contained virtually no creatine." (said at 1:40:58)

No published peer-reviewed scientific studies indexed in PubMed or Europe PMC were found evaluating the chemical composition or creatine content of commercial creatine gummy brands sold on Amazon. While independent consumer testing reports or industry analyses (such as commercial third-party laboratory testing circulated in trade/fitness media) may have examined these products, no corresponding peer-reviewed academic publication could be verified.

2:19:08Lauren Colenso-Sempleunverifiedvery low

Performing specific warm-up sets with lighter loads through a full range of motion is as effective for mobility and preparation as a general dynamic warm-up.

"I think a, you know, a dynamic general warm-up versus a specific like let's do some of the target exercise with lighter loads and move through that. They can be equally effective." (said at 2:19:08)

No directly matching published records comparing specific warm-ups (performing sets of the target exercise with lighter loads through full range of motion) versus general dynamic warm-ups for acute mobility and resistance training preparation were retrieved within the search budget. This does not prove the claim false, but direct comparative evidence could not be verified from the fetched records.

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.