Yoga is useful in helping to increase lung capacity but is not aerobic with the exception of ashtanga which fast-paced. Some yoga postures are weightbearing, but to maintain bone density, yoga should be combined with lifting light weights, and other bone-building exercises such as walking. Only burns 200 calories an hour but creates long, lean muscles and tones the abdomen. Good for flexibility. Thee exercise and philosophy of yoga helps reduce anxiety, depression and hostility, as well as boosting your mood and helping you to sleep better.