Sprinting trains the anaerobic and aerobic energy systems. It has been proven that interval sprint training not only builds anaerobic power, but also increases VO2 max as effectively as long slow distance running. The damage on your joints is far less than jogging and way more effective than walking. Sprinting builds power, strength, speed, balance, coordination, and it is fun to do. The monotony of jogging for 45 minutes to an hour can be extremely boring and is ineffective for accelerating fat loss. If you want lean, strong muscle, than sprinting is the answer.
Contrary to popular belief, having less muscle mass does not make you run faster. Squatting heavy weights strengthens your bones, tendons, and ligaments in addition to your muscles, thus reducing injury. Imagine if you can squat your body weight. Each step you take when you run will require a certain amount of energy. Now imagine if you can squat 2x your body weight. Each step now takes much less energy thus taxing your cardiovascular system much less. Obviously we’re talking about quality lean muscle mass here and just any mass.
Check out CrossFit Endurance’s FAQ which goes into detail about the theory behind strength and anaerobic training for the purpose of improving aerobic activity (ie long runs).
Bench Press 3×5 or Wendler
One partner does burpees while the other partner runs. Repeat until you complete 100 burpees as a team.