For most of us, a very good answer to the exercise conundrum is to do a variety of activities on a weekly basis. We know this intuitively. Concentrating on one type of exercise will usually lead to the loss of other important benefits. Again for most of us, across-the-board benefits are required. We need to maintain or increase a healthful amount of lean muscle mass. We gain this benefit from strength training. We need to maintain or improve cardiovascular strength and health. These are obtained from aerobic-type exercise such as brisk walking, running, swimming, or bicycling.1 We need to maintain or improve flexibility and stretchability. These benefits are gained from yoga. Each category of physical fitness is necessary for ongoing health and well-being. Thus, each of the three main categories of exercise is needed to ensure we obtain the full range of benefits.
It's important to be aware that each exercise category provides a distinct benefit, and as such no individual category is a "better" than the others. Doing exercise consistently is what counts. Going further, consistently doing a range of types of exercise provides lasting health benefits. There might be times when a person chooses to focus on one specific category. That's fine, provided that the other two categories continue to be incorporated on a temporarily reduced basis. After a while, the person will usually choose to return to a broader approach.
Finally, most people are familiar with strength training and the various types of cardiovascular exercise. Not everyone is familiar with yoga. There are numerous other activities that promote flexibility and stretchability, and yoga is not the only means of obtaining these benefits. But many people have discovered that yoga in itself is complete exercise. Regular yoga practice provides strength training, cardiovascular training, and deep training of the proprioceptive system (the body's awareness of position in 3-dimensional space) which leads to improved agility and balance.2,3 Regular yoga practice adds lean muscle mass and lowers the heart rate (as a result of improved cardiovascular capacity). Those who do yoga are "light on their feet". Yoga is a remarkable exercise system and could be sufficient in itself for long-lasting health and wellness. But when a person adds a weight lifting program and specific cardiovascular training, the remarkable benefits of cross-training kick in. The overall gains achieved are noticeably enhanced. Thus, a broad program of strength training, cardiovascular training, and yoga can lead to the best results.
1Snel M, et al: Effects of Adding Exercise to a 16-Week Very Low-Calorie Diet in Obese, Insulin-Dependent Type 2 Diabetes Mellitus Patients. J Clin Endocrinol Metab 2012 May 8 (Epub ahead of print)
2Galantino ML, et al: Impact of Yoga on Functional Outcomes in Breast Cancer Survivors With Aromatase Inhibitor-Associated Arthralgias. Integr Cancer Ther 2011 July 6 (DOI: 10.1177/1534735411413270)
3Kiecolt-Glaser JK, et al: Adiponectin, leptin, and yoga practice. Physiol Behav 2012 Jan 27 (Epub ahead of print)