In general, resistance training naturally increases the body’s testosterone levels. However, not all types of resistance training are equally good for this matter.
According to research, heavy compound movements are the most beneficial for one’s anabolic hormones. Good examples of compound movements include bench presses, squats, deadlifts, pull-ups, and rows. Basically, testosterone levels benefit from any exercise that incorporates the movement of more than one muscle group. The more muscle groups, the better for your T.
However, this doesn't mean that isolation exercises have no benefits for your hormone levels. Some muscle groups respond better to isolation exercises than compound exercises.
Also, doing isolation exercises can prevent muscle growth imbalance. By mitigating muscle imbalance, your body is able to progress better in doing heavier compound exercises. This gives your body a better rate of improvement for progressive resistance training which has been proven to significantly increase testosterone levels.
However, some people say that the potential benefits just aren't worth the detrimental effects. Those who say this generally do so because they are thinking of the stress hormone cortisol and its negative effects on testosterone levels. Since exercise induces stress on the body, it's easy to assume that it increases the body’s cortisol levels.
Although there is a cortisol spike after exercise, this increase is really minimal. Definitely not high enough to have significant effects. Moreover, studies reported that beginners exhibit higher levels of resting testosterone and lower levels of resting cortisol after just 4 weeks of resistance training.
These benefits can be achieved if the strength training routine is done three times a week and every muscle group is trained with compound movements with sub-maximal effort.
Aside from the hormonal benefits of resistance training, it's also great for your bones. This is especially important when you hit the age of 40, since after this mark bone mass can decrease by 1% every year if left unchecked.
Research has shown that building muscle strength can slow down bone loss and even restore it. Also, the physical stress of exercise on the bones can boost the activity of bone-forming cells.
Additionally, resistance training builds strength and stability. By improving these qualities, older individuals are less likely to suffer accidental falls that can be harmful for the bones, especially in old age.