Use short sprint intervals with very brief rest periods to get conditioned and trigger a potent hormone response. With as little as five minutes of pain you’ll get significant gains by adding sprints to your training program.
Research done on Iranian wrestlers in the preseason found that short sprints with very brief recovery improves both aerobic and anaerobic performance, while crucially avoiding a catabolic state due to the heavy training load.
The participants performed two sprint sessions a week for four weeks in addition to their regular wrestling practice and weight training. The interval protocol took a total of four minutes and included six 35-meter sprints at maximum effort with 10-seconds rest.
After four weeks, the wrestlers improved peak power output on an anaerobic sprint test. They also improved maximal oxygen uptake by 5.4 percent and increased time to exhaustion on a graded exercise test from 356 to 471 seconds—a significant improvement that is likely due to decreased glycogen depletion and greater muscle buffering capacity.
Total testosterone and the testosterone to cortisol ratio improved significantly by the end of the study. Cortisol levels decreased by 12.6 percent—a small amount but still of import because it indicates that catabolic process were decreasing while anabolic response was boosted.
The evidence is valuable because it provides a conditioning model to use with elite athletes so that they don’t overtrain or experience an excessive stress hormone response.
If you are using sprints to train for a long competitive season, researchers suggest doing four weeks of sprints in the preseason conditioning phase. Then during the season, do brief sprint training segments for two weeks in order to peak for competition.