Cardiovascular fitness is vital for building your stamina regardless of what sport you participate in or which muscles you want to build. Cardiovascular training prevents your body from tiring and shutting down before your muscles do so. You can do cardio exercises such as swimming, running, bicycling or using an elliptical machine in the gym as a regular component of each workout to build greater stamina.

Doing sit-ups and crunches can help you develop stronger abdominal muscles, which, for example, will translate into greater running stamina and more power in your tennis games. Strong abdominal muscles also help prevent you from having back problems (or alleviate current back issues) and give you more stamina for any activity that includes your torso. To do sit-ups, lie down with your knees bent and your feet apart and flat on the floor. Contract your abdominal muscles, press your back into the ground and rise to a 45-degree angle from the floor with your arms folded across your chest (with each hand on the opposite shoulder). For crunches, do the same, except keep your hands behind your head instead of across your chest.

One of the best exercises to build stamina is weight lifting. According to research done by Tufts University, women who worked with weight machines or free weights for 45 minutes twice each week for a year were physiologically younger by 15 to 20 years than from when they started. While lifting heavy weights for a few repetitions at a time can be helpful in developing the power and size of your target muscles, this approach will not increase your overall stamina. To build stamina with weights, start out with less weight (half of the weight you normally work with) and perform twice as many repetitions as you normally would perform. Above all, be consistent with the amount of times you do weight lifting and the duration for which you do it each week.