The body becomes more efficient in every possible way through training, including hormone production. Resistance training has been proven to increase the amount of testosterone and HGH in the body, along with other hormones the body produces during maximal exercise. These hormones are important to muscle hypertrophy. The following training strategies, implemented either individually or in combination, will result in acute increases of testosterone and growth hormone.
High intensity, high total work volume, and short rest periods. An example of this would be a 10RM (or just exercises with heavy resistance) for 3 sets of each exercise and only resting for 30 - 60 seconds.
This will result in high lactate concentrations and a disruption to the acid-base balance, leading to an increase in growth hormone secretion.
Supplement the diet with carbohydrates and protein before and after the workout.
Large muscle group exercises (i.e. deadlift, power clean, squat)
Heavy resistance (85% - 95% 1RM)
Moderate to high volume of exercise (multiple sets or multiple exercises)
Short rest intervals (30-60 seconds)
There are some important things to note about the endocrine system's response to exercise:
The optimal hormonal response is relative to the exercise stimulus
Hormonal responses only occur in the tissue exercised
The recovery from anaerobic exercise promotes anabolism: building up from more simple compounds
Inappropriate exercise prescriptions can result in a net catabolic effect -- too much training releases too much cortisol into the system, which will continue to stimulate protein to carb conversions for energy after the workout is completed and will stunt hypertrophy efforts.
Adaptations can be acute or chronic.