Researchers studied training responses in two groups of men (aged 30 and 62). The men participated in a 10-week cyclic training program. Total testosterone, free testosterone, cortisol, lactate and ACTH were tested.
To assess exercise-induced responses, an exercise test with high resistance was used (4 sets of squats of 10 repetitions with 90 seconds of rest between sets).
- there was an increase in squat strength in the 30-year-old group by ~ 17.3%
- there was an increase in squat strength in the 62-year-old group by ~ 10.8%),
- muscle cross-sectional area increased on average from 186 to 204 in the 30-year-old group and from 159 to 169 cm2 in the 62-year-old group,
- total testosterone concentration due to exercise increased by 20.3 nmol/l in the 30-year-old group and by 15.7 nmol/l in the 62-year-old group,
- the concentration of free testosterone increased by 80 pmol / l (in the 30-year-old group) and by 60 pmol / l in the 62-year-old group,
- changes in growth hormone and IGF-1 levels were insignificant in the 62-year-old group (initially GH increased, then decreased in subsequent weeks of observation),
- paradoxically, regular strength training caused a decrease in growth hormone levels in 30-year-olds after 3, 6 and 10 weeks of training,
- resting cortisol levels were much lower in both groups in the following weeks of training
Strength training had an effect on testosterone levels, much higher in young men, but noticeable in those over 60 years old. However, for the sake of clarity, it is a temporary increase, which disappears after ~ 60 minutes from the end of work.
The most important conclusion that can be drawn from this study is that even in people over 60 years of age it is possible to increase muscle strength and girth. This type of training is anti-inflammatory
Contrary to popular myths, strength training based on multi-joint exercises led to a marked decrease in the concentration of growth hormone in young men. Again, Internet myths are not confirmed, because despite the lack of IGF-1 concentration increase, the concentration of IGF-1 binding protein (IGFBP-3), which makes somatomedin-C biologically inactive, increased significantly. The effect was negligible in people over 60 years old.