HoldsUp

Stuart Phillips

McMaster University

Stuart Phillips, PhD, is a professor of kinesiology and the director of the Physical Activity Centre of Excellence at McMaster University. His research focuses on the roles of exercise and nutrition in regulating human skeletal muscle protein turnover and body composition, particularly during aging. His published work investigates resistance training protocols, muscle hypertrophy mechanisms, dietary protein requirements, and physical function recovery.

47 claims checked on air: 1 context 1 contradicted 27 supported 18 unverified 1 flagged

What they said on air - unverified

0:05:43unverifiedlowStuart Phillips, PhD, on Building Muscle with Resistance Exe

On a population level, aging humans lose approximately 1% of muscle mass per year.

"And usually what we say on a population level, it's about a 1% loss of muscle mass per year" (said at 0:05:43)

No published record matching the claim that aging humans lose approximately 1% of muscle mass per year on a population level was located in the evaluated abstracts; this does not prove the claim false. While progressive age-related loss of skeletal muscle mass and function (sarcopenia) is well-documented in clinical consensus literature, specific population-wide rate estimates vary depending on the age cohort, sex, measurement modality, and physical activity levels.

0:10:19unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Androgen deprivation therapy in men with prostate cancer induces a hypogonadal state accompanied by muscle mass loss.

"if you take men and they have a diagnosis of prostate cancer, they're often put on androgen deprivation therapy. So they're taken from a normal testosterone state to a hypogonadal state, and yeah, they lose muscle mass." (said at 0:10:19)

The claim is well supported. Androgen deprivation therapy (ADT) for prostate cancer suppresses circulating testosterone to castrate (hypogonadal) levels. A well-established adverse effect of this severe testosterone suppression is a significant decline in skeletal muscle and lean body mass, which often leads to sarcopenia and increases in fat mass unless counteracted with targeted resistance exercise. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

0:25:47unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Exercise training can increase the size of the hippocampus in the human brain.

"15, 20 years ago if you said, "Well, you can change the size of your hippocampus and your brain with exercise," they'd have been like, "Right."" (said at 0:25:47)

Randomized controlled trials and meta-analyses demonstrate that exercise training can modify hippocampal volume in humans. In a landmark randomized controlled trial of 120 older adults, 1 year of aerobic exercise training increased anterior hippocampal volume by approximately 2%, reversing age-related volume loss. Subsequent systematic reviews and meta-analyses of controlled exercise trials have confirmed significant positive effects on hippocampal volume compared to non-exercising controls, primarily reflecting a combination of volume enlargement and preservation against expected age-related atrophy. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

0:25:55unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Exercise produces improvements in depressive and anxiety symptoms of a magnitude comparable to pharmaceutical interventions.

"You get, you know, improvements in mood, you get improvements in depressive symptoms, anxiety, and everything, almost of the magnitude similar to people taking pharmaceutical interventions for those things." (said at 0:25:55)

Systematic reviews and network meta-analyses of randomized controlled trials demonstrate that exercise and physical activity produce reductions in depressive and anxiety symptoms with effect sizes comparable to antidepressant medications and standard psychological interventions, particularly in non-severe depression. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

0:28:50unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Heat shock proteins act as molecular chaperones that prevent protein misfolding and help mitigate muscle atrophy.

"what we understand now is that they chaperone, or they act as essentially little proteins that bind to other proteins to prevent them from being what we call misfolded... And we're beginning to see more and more that you can alleviate muscle atrophy" (said at 0:28:50)

Heat shock proteins (HSPs) are a well-characterized family of molecular chaperones whose primary function is assisting proper protein folding and preventing the aggregation of misfolded or damaged proteins. Extensive preclinical and mechanistic research demonstrates that HSPs (such as Hsp70, Hsp90, Hsp25, and αB-crystallin) protect skeletal muscle proteostasis, suppress key atrogenic pathways (including the ubiquitin-proteasome and autophagy-lysosome systems), and help mitigate muscle wasting during conditions of disuse, denervation, and aging. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

0:48:57unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Free-form leucine is readily absorbed by the body.

"No, you absorb it in free form. In fact, it's really readily absorbed." (said at 0:48:57)

No published record matching the claim that free-form leucine is readily absorbed by the body was located; this does not prove the claim false.

1:03:10unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Leucine activates muscle protein synthesis primarily through mTOR signaling.

"Leucine goes through mTOR. Its dysregulation is involved in all kinds of processes, including cancer and lots of other things. So it has a really centrally important role in integrating all of those anabolic signals." (said at 1:03:10)

Extensive mechanistic and human clinical evidence demonstrates that leucine stimulates skeletal muscle protein synthesis primarily via activation of the mechanistic target of rapamycin (mTOR / mTORC1) signaling pathway. Leucine acts as a key nutrient sensor and signaling trigger for translation initiation and protein synthesis, and mTOR is widely recognized as a central integrator of anabolic signals whose dysregulation is implicated in metabolic dysfunction and oncogenesis. [citation dropped: PMID did not verify]

The search did find related studies, but none that directly tests this claim:

1:10:50unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

A meta-analysis by Brandon Roberts showed that men and women achieve the same relative muscle growth gains relative to baseline in response to resistance training.

"and this is a meta-analysis now, a guy named Brandon Roberts did this one, and you resistance train them relative to what they started with, everybody goes up the same amount. Women get the same amount of muscle growth as men do, but they had less muscle to start with" (said at 1:10:50)

A 2020 systematic review and meta-analysis led by Brandon M. Roberts evaluated sex differences in response to resistance training among young to middle-aged adults. Analyzing 12 hypertrophy outcomes across 10 studies, the authors found no statistically significant difference in relative muscle growth between males and females (effect size = 0.07 ± 0.06; p = 0.31; I² = 0%), supporting the claim that relative muscle hypertrophy gains are similar between sexes. [citation dropped: PMID did not verify]

1:16:40unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Bone composition is approximately 40% protein by weight, structured as a layer of collagenous protein.

"Your bone is actually about 40% by composition protein. It's not just a stick of chalk. There's a layer of collagenous protein around it." (said at 1:16:40)

No published record matching the specific claim that bone is approximately 40% protein by weight structured as an outer layer of collagenous protein was located; this does not prove the claim false.

1:18:45unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Individuals with Laron syndrome (growth hormone receptor deficiency) do not develop cancer.

"and this is where you've had Dr. Longo on the show before, he shows in certain populations of dwarves, for example, who have a particular type of dwarfism and lack of growth hormone receptor, they're actually—they don't get cancer." (said at 1:18:45)

Longitudinal cohort studies by Dr. Valter Longo, Dr. Jaime Guevara-Aguirre, and colleagues demonstrated that individuals with growth hormone receptor deficiency (Laron syndrome) have a dramatically reduced incidence of cancer compared to unaffected relatives, but cancer is not completely absent. In a 22-year follow-up study of the Ecuadorian cohort, one nonlethal malignancy was documented among GHR-deficient individuals (compared to a 17% cancer prevalence in unaffected controls). An international survey of 230 patients with Laron syndrome similarly observed zero reported cancer cases, indicating near-complete protection, though an absolute claim that they 'do not get cancer' slightly overstates the findings. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

1:25:05unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Higher levels of leisure-time physical activity are associated with a reduced risk in 13 of the 26 most common types of cancer.

"13 of the 26 most common types of cancer are lower in people who have higher levels of leisure-time physical activity." (said at 1:25:05)

A landmark pooled analysis of 12 prospective cohorts comprising 1.44 million adults (Moore et al., 2016) investigated the association between leisure-time physical activity and 26 types of cancer. Comparing high versus low levels of leisure-time physical activity (90th vs. 10th percentile), physical activity was statistically significantly associated with a reduced risk of 13 specific cancers: esophageal adenocarcinoma, liver, lung, kidney, gastric cardia, endometrial, myeloid leukemia, myeloma, colon, head and neck, rectal, bladder, and breast cancer. [citation dropped: PMID did not verify]

1:27:45unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

In adults, exogenous growth hormone acts primarily as a fat-mobilizing hormone and does not significantly promote muscle mass accretion.

"in the case of growth hormone, it's actually a fat-mobilizing hormone. That's one of its great side effects if you're taking exogenous growth hormone; you notice you get leaner. It probably doesn't do much for your muscle." (said at 1:27:45)

Multiple systematic reviews and meta-analyses of randomized controlled trials confirm that exogenous growth hormone (GH) acts primarily as a potent lipolytic (fat-mobilizing) agent, reducing body fat mass and increasing circulating free fatty acids and glycerol. Although GH administration increases measured lean body mass (or fat-free mass), studies demonstrate that this change is driven primarily by extracellular fluid retention and connective tissue synthesis rather than myofibrillar muscle protein synthesis, contractile muscle hypertrophy, or gains in muscle strength. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

1:35:28unverifiedlowStuart Phillips, PhD, on Building Muscle with Resistance Exe

The heat shock protein response can be locally induced by heating a single limb rather than requiring whole-body hyperthermia.

"it seems that the heat shock response is something you can locally induce, right? It doesn't have to be a sauna, so you can heat one leg and not the other leg, for an example." (said at 1:35:28)

No published record matching the claim that the heat shock response can be locally induced by heating a single limb rather than requiring whole-body hyperthermia was located; this does not prove the claim false.

1:35:48unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Local tissue heating opens capillaries and increases tissue perfusion.

"And again, the cardiovascular effects to do with that and opening up capillaries and so more perfusion of them, I mean, there's all kinds of things that are suggestive that there could be something going on there, yeah, for sure." (said at 1:35:48)

Local tissue heating directly induces thermal hyperemia, increasing tissue perfusion and causing microvascular capillary recruitment (opening of capillaries). Human physiological studies show that local hyperthermia produces substantial, localized increases in microvascular blood flow and tissue oxygenation, while direct microvascular imaging confirms that heating increases the number of open, perfused capillaries and the time precapillary sphincters remain open. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

1:38:32unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

High-dose omega-3 supplementation attenuated disuse muscle atrophy and accelerated muscle recovery following two weeks of single-leg immobilization in young women.

"We supplemented one group with very high-dose omega-3 fatty acids and we supplemented the other group with sort of a corn oil placebo, and then we braced one of their legs for our local disuse atrophy model for two weeks. And the women on the omega-3 supplement saw a really mild disuse atrophy response, and then returned to normal much quicker than the other group who saw a much greater atrophic response and didn't get back to normal after two weeks of we call it passive remobilization." (said at 1:38:32)

The speaker accurately describes the results of a randomized controlled trial (McGlory et al., 2019) in 20 healthy young women. Participants received either 5 g/day of omega-3 fatty acids or a control oil starting 4 weeks prior to 2 weeks of unilateral leg immobilization, followed by 2 weeks of recovery. The omega-3 group showed significantly attenuated loss of muscle volume during immobilization (8% reduction vs. 14% in the control group) and fully recovered their muscle volume after 2 weeks of returning to normal activity, whereas the control group remained significantly below baseline. [citation dropped: PMID did not verify]

1:44:10unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Creatine monohydrate supplementation improves cognitive performance and brain function.

"Now the brain and the cognitive side of things is is, you know, the evidence is growing in that area, too." (said at 1:44:10)

The speaker's statement that evidence is growing regarding creatine's effects on brain and cognitive function is supported by recent systematic reviews and meta-analyses. A 2024 systematic review and meta-analysis of 16 randomized controlled trials (RCTs) found that creatine monohydrate supplementation produced modest, statistically significant improvements in memory (SMD = 0.31), attention time, and processing speed, though overall cognitive function and executive function showed no significant differences. A 2023 meta-analysis of RCTs in healthy individuals similarly demonstrated a significant positive effect of creatine supplementation on memory performance (SMD = 0.29), with pronounced benefits observed in older adults. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

1:44:10unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Over 40 years of research on creatine supplementation has shown no causal link to kidney damage or increased cancer incidence, with adverse events being rare.

"There was a lot of talk about it's damaging your kidneys, it's doing, you know, this you shouldn't, you know, it's a it's a guanidino compound, etc., etc. Um, we've got 40 years' worth of data with people on the supplement now and and we're not seeing some sort of rife wave of of people who used it getting various forms of cancer, etc., etc. All the data reviewing it from a safety standpoint has given it two thumbs up. The adverse events are are rare" (said at 1:44:10)

Extensive clinical trial data and multiple systematic reviews and meta-analyses show that creatine monohydrate supplementation does not cause kidney damage in healthy individuals, does not increase cancer incidence, and is generally safe with rare adverse events. While creatine intake leads to minor increases in circulating serum creatinine, true measures of renal function and glomerular filtration rate (such as Cr-EDTA clearance, serum urea, and proteinuria) remain unaffected, reflecting increased metabolic turnover of creatine rather than renal injury. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify] [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

1:45:46unverifiedvery lowStuart Phillips, PhD, on Building Muscle with Resistance Exe

Dr. Mark Tarnopolsky prescribes 4 to 5 grams of creatine monohydrate daily to patients with neuromuscular diseases, such as mitochondrial myopathies and muscular dystrophies, to treat muscle weakness.

"A good friend of mine, Mark Tarnopolsky, neuromuscular physician, has all of his neuromuscular patients on it. So I think that that's a fairly robust endorsement of what it can do for people with compromised muscle function, and he recommends that these people just start with a dose of about, you know, four to five grams of creatine a day." (said at 1:45:46)

Dr. Mark Tarnopolsky, a neuromuscular specialist and researcher, has extensively evaluated and recommended creatine monohydrate supplementation (typically at maintenance doses of approximately 3 to 5 grams daily, or ~0.1 g/kg/day) for patients with neuromuscular and neurometabolic conditions, including muscular dystrophies and mitochondrial cytopathies. Clinical trials led by Tarnopolsky and Cochrane systematic reviews co-authored by him demonstrate that creatine monohydrate supplementation improves muscle strength and high-intensity performance in muscular dystrophies and mitochondrial cytopathies. [citation dropped: PMID did not verify] [citation dropped: PMID did not verify] [citation dropped: PMID did not verify]

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