More Explosive Power with Testosterone

Like feeling strong...it's your testosterone levels!  Higher testosterone levels are correlated with maximal strength levels and higher resistance levels of fatigue in weightlifters⁸. Additionally, testosterone levels are directly related to how high a person can jump and how fast a person can run²³. Testosterone appears to augment power activities and activities with high force output. For example, work from Bosco and colleagues tested 97 high level athletes involved in various sports.  They found that the highest values of testosterone were for jumping performance in sprinters, while the lowest values were in cross-country skiers, and intermediate values were found in soccer players²³. They also found that testosterone was directly related to both the height in the countermovement vertical jump and average sprinting speed. What is most fascinating is that actual increase in testosterone concentrations in a maximal continuous vertical jumping test for 60 seconds in professional soccer players was directly correlated with average power output¹⁵. One study documented that without testosterone, you can expect impaired strength gains from a heavy resistance training protocol. In the study, young men performed several weeks of performing a resistance training program while receiving a medication that turn blunts the production of testosterone. The strength-training period of eight weeks included exercises for all major muscles (three to four sets per exercise x six to 10 repetitions) and one-minute rest periods between sets. The protocol was designed to cause acute increases in testosterone, which has been validated by previous investigations. The subjects who received the testosterone suppression medication had a decrease in testosterone that was 10 percent lower than that of normal males, whereas testosterone remained constant in the placebo group. So here is where the importance of testosterone becomes clear for muscle strength and weight loss.  The group that received the testosterone suppressing medication showed no changes in strength after training, whereas the placebo group had increased strength gains. Body fat mass increased in the testosterone suppression group while it decreased by 1.3 pounds in normal group. The testosterone blunting medication group made a small gain in lean mass, but not as much as the placebo group²⁴.  So this study demonstrates that maintaining or increasing testosterone levels are essential for strength gains.  

Testosterone and Resistance Training Intensity

An intense bout of resistance exercise produces acute changes in testosterone which have been linked to those cellular processors involved in

protein synthesis and muscle growth. Resistance training routines, that incorporate short rest periods between sets, produce higher testosterone concentrations than training protocols that use the same workload and prolonged rest periods.  For example, male strength athletes performed two different training intensities while maintaining similar rest periods (3 minutes).  The first session consisted of maximal strength training session (20 sets x 1 RM x 100 %), while one week later they performed a sub-maximal bodybuilding training session (10 sets x 10 RM x 70%).   Testosterone levels with maximal training (20 sets x 1 RM) did not change immediately and 1-hour post exercise, however testosterone and cortisol responses to submaximal training (10 sets x 10 RM) increased during after and 1 hour post-exercise with the submaximal training loads¹.  It was concluded that high intensity resistance exercises can stimulate testosterone production, while low intensity heavy resistance exercise does not.  If you perform a high intensity bout of heavy resistance exercise, not matter what your previous training experience you will increase testosterone production. One study compared bodybuilders and powerlifters of the same age, size, and experience to an intense resistance training protocol, which shorted rest periods.  The experimental sessions consisted of 3 sets of 10 repetitions for 10 exercises with 10-second rest periods between sets and 30 to 60 second rest periods between exercises.  Testosterone increased in both groups, but regardless of previous training experience, both bodybuilders and powerlifters had similar increases in testosterone concentrations².

Bodybuilding Protocols Increase Testosterone Greater than Powerlifting Protocols.

Testosterone responses to resistance training in men are less with low intensity resistance training protocols than those that use high intensity. Raastad et al. compared testosterone responses to two protocols, which utilized different intensities of squats, front squats, and leg extensions yet workload remained constant.  One protocol was a moderate intensity (70% of a 1-RM) and the other protocol was a high intensity workload (100% of a 6-RM).  Testosterone responses were higher during and one hour after the 70% protocol compared to the 100% protocol³. So now you are understand that training intensity should be at least 70% or more to stimulate sufficient rises in testosterone production.