Testosterone is a hormone produced in the male testes. During a boy's pubescent years (ages 9 to 14), there is an increase in production that leads to male secondary sexual characteristics such as a deeper voice, more muscle mass, facial hair growth and enlargement of the Adam's apple (among others). Some teenage boys experience these puberty changes at later ages than others. The timing of puberty is often genetically determined (through heredity), but other factors can play a role in delaying it, such as poor nutrition, physical trauma and certain diseases. Stimulating testosterone production naturally is possible in teen boys, although in rare cases hormone therapy may be needed to trigger and complete puberty.
Having a kettlebell is essentially halfway to having all the exercise equipment you need. From swings to deadlifts, presses, cleans, snatches and goblet squats, grabbing a kettlebell can help you unlock a near-limitless amount of full-body exercises that can string together a monster HIIT workout. If you plan to purchase just one, our advice is to chose a weight according to an exercise that you might find more challenging. You want a KB that's heavy enough to tax you with moves your efficient with but light enough that you can still move it without compromising your form.
$ for a 17-pounder at