Yoga is often a misunderstood mode of exercise. The tradition of yoga originated at least 5,000 years ago in India. It was intended to help redirect a person’s search for perfection and happiness through external sources (power and wealth) to internal, innate sources; it was never intended to maximize calorie expenditure. Hatha Yoga (the yoga of physical discipline) is the term most used to describe the practice of yoga. Technically speaking, almost all types of yoga could be considered “Hatha”.
In an earlier blog post: “Yoga For Flexibility” by Mike Stack, he states, “It is important to understand that I am not saying yoga is bad or ineffective. Yoga confers a strong psychological benefit and does offer exercisers another exercise modality. On both of those levels, I strongly encourage those of you performing yoga to keep doing it!”
I want all readers to understand that I agree with the statement above. The primary goal of this blog is to discuss the metabolic demands of yoga compared to the metabolic demands recommended for improvement in cardiovascular fitness and weight management.
A Common Misconception
When setting an exercise goal for weight loss purposes, it is not uncommon for individuals to count a yoga session as one day of cardiovascular exercise. Though yoga does count as “physical activity”, it is important to understand that, in terms of metabolic demands, yoga is not interchangeable with modes of cardiovascular exercise such as walking, jogging, circuit training, swimming or biking.
A study from Texas State University, measured HR (heart rate) and VO2 (oxygen consumption, which reflects the intensity of the exercise bout) in three scenarios:
1.) At rest
2.) Following a 30 minute Hatha Yoga routine
3.) Following a 30 minute bout of treadmill walking at 3.5 mph
Although the 30 minutes of yoga did result in 24% higher heart rate and a 114% greater VO2 compared to at-rest measures, these values did not come close to the metabolic demands of treadmill walking at 3.5mph. Hatha Yoga required a 21% lower HR and 54% lower VO2 than treadmill walking. The average exerciser dedicates approximately 60 minutes to their workout; the following numbers show calories burned in 60 minutes for a 150lb person.
• At Rest = 74 calories
• Hatha Yoga = 155 calories
• Treadmill Walking/3.5mph = 330 calories.
There is a very dramatic difference in these numbers. Walking burned more than twice the calories of the yoga session.
What Is Recommended?
The American College of Sports Medicine recommends that healthy, fit adults exercise at 65-90% of predicted maximal heart rate (MHR) or 50-85% of their VO2 reserve. During the Hatha Yoga routine, the participants exercised (on average) at 56.89% of MHR and 14.5% of VO2 reserve. These values are much lower than the recommendations above.
Take Away Message
Does performing yoga burn calories to help you stay fit?
Yes, because something is always better than nothing.
Is it the most effective way to burn calories and reach your weight loss goals?
Other forms of popular yoga such as Bikram or “Hot” yoga (performed in a humid room at 105°F) also have shown to be less effective than standard cardiovascular exercise when it comes to burning calories. Although Bikram yoga can be labeled “high-intensity” from a yoga standpoint, studies have failed to show significant losses in body fat from this type of exercise. Interestingly, we actually burn fewer calories when exercising in very hot, humid temperatures. Exercise intensity can be reduced 5-20% in these settings because blood flow must be redirected from the skeletal muscles to the skin, which assists in the cooling process. An increase in sweat does not equal fat loss. Sweat is fluid loss, which only means “weight loss” until you rehydrate.
How to Spend Your Time
If you are currently participating in yoga, and enjoying it, by no means am I telling you to stop. But, if your goal is to lose body fat and you have limited time each week, your time would be better spent engaging in some sort of cardiovascular exercise. Although studies show yoga may be insufficient for enhancing cardiovascular fitness and promoting weight loss, it still is considered a viable mode of exercise for increasing flexibility and promoting a small improvement in muscular fitness. I would suggest using yoga as an adjunct to regular aerobic exercise to enhance overall fitness rather than using yoga as a primary mode of exercise.