The effects of aerobic, resistance, and combination training on insulin sensitivity and secretion in overweight adults from STRRIDE AT/RT: a randomized trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 25882384 · doi:10.1152/japplphysiol.00509.2014
What was done
Sedentary, overweight adults (mean age 50 years, mean BMI 30 kg/m2, moderate dyslipidemia; N = 196 randomized) were assigned to one of three 8-month exercise interventions: 1) Resistance training (RT): 3 days/week, 8 exercises, 3 sets of 8–12 repetitions; 2) Aerobic training (AT): ~19.2 km/week at 75% peak oxygen consumption; 3) Combination training (AT/RT): both protocols combined. Insulin sensitivity, glucose effectiveness, and disposition index were assessed via frequently sampled intravenous glucose tolerance tests with minimal modeling both acutely (within 24 hours of the last session) and after 14 days of detraining. Overall, 144 subjects completed the intervention and 88 completed all testing visits.
What was found
AT/RT produced significantly greater improvements in insulin sensitivity, glucose effectiveness, and disposition index compared to either AT or RT alone (all P < 0.05). Neither AT alone nor RT alone led to acute or sustained improvements in the insulin sensitivity index. Approximately 52% of the improvement in insulin sensitivity achieved by AT/RT was retained 14 days after the last exercise bout. Exact numerical changes and baseline values were not reported in the abstract.
Why it matters
This study shows that combining aerobic and resistance training provides superior and partially persistent improvements in insulin action and beta-cell function compared to either exercise mode alone in sedentary, overweight adults.
Limits
Participant attrition was substantial, with only 88 of 196 randomized participants completing all pre- and post-intervention testing visits. The AT/RT arm required twice as much exercise time as either single-modality arm, confounding the combination of modalities with total exercise dose. Absolute point estimates, variance, and confidence intervals were not reported in the abstract.
Cited by
- contradicts Minute-for-minute over short durations such as 30 minutes per day, strength training leads to greater improvements in insulin sensitivity than aerobic training.