Long Rest Interval Promotes Durable Testosterone Responses in High-Intensity Bench Press.
Level 2 - randomized trial
Within-subject crossover trial
PubMed 26466135 · doi:10.1519/JSC.0000000000001237
What was done
Ten resistance-trained men (age 25.2 ± 5.6 years, body mass 78.2 ± 5.7 kg, relative bench press strength 1.3 ± 0.1 kg/kg) completed two bench press workouts separated by one week in a within-subject crossover design. Each session consisted of 5 sets of 3 repetitions at 85% of 1-repetition maximum, using either 1-minute or 3-minute rest intervals between sets. Total testosterone (TT), free testosterone (FT), cortisol (C), testosterone/cortisol ratio (TT/C), and growth hormone (GH) were measured pre-workout (PRE), immediately post-workout (T0), 15 minutes post-workout (T15), and 30 minutes post-workout (T30). Rating of perceived exertion was recorded before and after each set.
What was found
The abstract reports directions and significance but no absolute numerical hormone values or effect sizes: - Total testosterone increased at T0, T15, and T30 compared with PRE in both conditions, but 1-minute rest showed significant decreases at T15 and T30 relative to T0. - Free testosterone increased at T0 and T15 versus PRE with 1-minute rest, and at T15 and T30 versus PRE with 3-minute rest. - Cortisol did not change across post-exercise time points for either rest condition. - The TT/C ratio significantly increased at all post-exercise points versus PRE for both rest conditions. - Growth hormone showed no significant changes for either rest duration.
Why it matters
These findings suggest that when training volume and intensity are equated, longer rest periods between sets may sustain acute post-exercise circulating testosterone elevations longer than short rest periods.
Limits
The sample size is very small (n = 10) and limited entirely to young resistance-trained men performing a single upper-body movement. No numerical concentrations or confidence intervals are reported in the abstract. Only acute hormone responses up to 30 minutes were measured, so long-term neuromuscular or hypertrophic adaptations cannot be inferred.
Cited by
- contradicts Shorter rest intervals between sets promote greater acute post-exercise elevations in growth hormone, testosterone, and IGF-1.