Most research on hormonal response to training has focused on high volume with moderate loads and brief rest periods. Little data exists on the impact of lower-volume strength routines with longer rest periods.


University of Rio de Janeiro researchers examined how rest periods affected testosterone levels in response to heavy-load, low-volume workouts. Each workout consisted of five sets of three reps using 85% of 1RM, with either a one- or three-minute rest period.


Total testosterone was elevated after both workouts, but it began to fall rapidly at 15 minutes and 30 minutes post-workout with one minute of rest compared with three minutes of rest. Free testosterone is where things really got interesting. A one-minute rest produced a spike that lasted only 15 minutes. A three-minute rest saw levels climbing steadily at 15 minutes and at 30 minutes.

Chest arms weights


A three-minute rest led to greater and longer lasting increases in both total and free testosterone levels.


This study proves that heavy-weight, low-volume training with longer rest periods significantly boosts testosterone levels. The best strategy is to use a periodized routine that starts with light weight, high reps, and short rest periods and then progresses to heavy weight, low reps, and longer rest periods. – FLEX