Some forms of exercise to consider for your cross training
Aerobics classes. Aerobic exercise forces the heart and lung muscles to work harder than normal, thereby strengthening them. It burns calories in the form of glycogen (the body's stored energy source), which is broken down to produce glucose as muscle "fuel.” Once the glycogen is used up, fat is metabolized, leading to weight loss.
Aqua aerobics. When aerobics is performed in a swimming pool, the water provides both support – perfect for older people and those with injury problems – and a resistance which is 12 times greater than air. Exercises are much harder.
Ashtanga yoga. Ashtanga is a more dynamic form of yoga than Hatha or Iyenga, with poses and moves that increase flexibility and balance, and work the abdominals and "core" muscles (those that stabilize the spine and pelvis, running the entire length of our torso). Ashtanga incorporates a number of yoga poses, known as "power poses,” which help train the muscles.
Bikram yoga. Widely regarded as the most intense form of yoga, Bikram comprises 26 postures and two breathing exercises in 90 minutes, all performed in a room heated to 105F, which elevates the intensity of the workout. It raises the body's core temperature, so that it has to work to maintain homeostasis (the physiological regulation of its inner environment to ensure its stability), making you breathe harder and sweat profusely.
Boxing. A typical boxing session involves footwork, speed, and agility training with skipping and speed balls, and strength, power, and endurance work on pads or heavy bags. It builds powerful arms and shoulders, while the intense cardio work burns calories, and crunches, push-ups and other bodyweight exercises ensure a full-body workout. Boxing training is anaerobic, because the intensity of the workout pushes your body through its anaerobic threshold, where you are expending oxygen faster than you can breathe it in, which works your body harder than purely aerobic training.