Depending on the sport/activity of your choice, the demands of that sport should influence how you train. Such factors to consider in training programs are the energy systems being used. For example, anaerobic/alactic exercise includes short powerful bursts of activity typically lasting 30 seconds or less. Activity at higher intensity levels performed greater than 30-45 seconds start to stress the anaerobic system, which often produces lactic acid as a bi-product. This is known as “the burn” in the legs. Other factors to be considered are the work/rest ratios and movement patterns performed in your activity. This may influence your exercise program to include parallel stance (squats), split stance (lunges) or single leg stance (step ups) based on what activities you love to do. Remember, move well so you can move often.