Is Hot Yoga Good for You?〜ホットヨガは体に良いのか?





Is Hot Yoga Good for You?

Reader question
Q: Is hot yoga good for you?

A:Yoga can be traced back to ancient India, and though research is limited, studies suggest it is safe for most people and may have multiple benefits, including easing chronic low-back pain and improving some heart disease risk factors. But even less is known about hot yoga, a more recent form of the mindbody practice. Hot yoga is performed in a room heated to between 80 degrees and 105 degrees Fahrenheit and may be more physically rigorous than regular yoga, making practitioners susceptible to dehydration and muscle injuries, said Casey Mace, an assistant professor of public health at Central Washington University in Ellensburg, Wash.

A: ヨガの歴史は、はるか古代インドにまで遡ります。研究によれば多くの人に慢性的な腰痛の緩和や心臓病の危険因子を減らすなど沢山のメリットがあると言われています。
しかし、その全てが解明されているわけではありません。そして、さらに知られていないことが多いのが、より最新の心身の鍛錬法とされるホットヨガについてです。ホットヨガは80℉~100℉(27℃~38℃)に加熱された室内で行われるため、通常のヨガよりも体に負荷がかかることが多く、そのために脱水症状や筋肉の損傷を引き起こしやすくなると、アメリカ・ワシントン州のエレンズバーグにあるセントラルワシントン大学で公衆衛生学を教えるCasey Mace助教授はコメントしました。

“People may assume the warnings and benefits and possible risks are the same for all types of yoga, and that’s simply not true,” said Dr. Mace, who has studied hot yoga. Her research found that hot yoga practitioners reported benefits like greater flexibility and improvements in mood, fitness and stamina, but that over half had experienced dizziness, lightheadedness, nausea or dehydration.



“There may be a misconception that these feelings are normal, but they’re not,” she said. “If people are feeling dizzy or have headaches or feel weak or fatigued, it may be related to fluid loss. They should take a break, cool down and get hydrated. Proper hydration is key.”



Still, Dr. Mace said, “Hot yoga is generally safe, and the side effects we’re seeing are generally mild,” though as with any kind of yoga, the practice does have risks. Doctors in Chicago reported this summer on a case involving a healthy 35-year-old woman who went into cardiac arrest induced by heat stroke during a hot yoga class. The woman survived.



Muscle and joint injuries may be more common with hot yoga because the heat makes people feel more limber than they actually are, and they may overdo it, but data on injuries is also limited, said Carol Ewing Garber, a professor of movement science and kinesiology at Teachers College, Columbia University, and past president of American College of Sports Medicine. “You have to be a bit cautious when you look at studies, because they are conducted with high-quality, well-trained yoga teachers under the best of circumstances,” Dr. Garber said. “The reality is that out in the real world, there is a lot of variability across instructors in terms of their training.”

American College of Sports Medicine(Sports Medicine:スポーツ医学)の元学長で、現在コロンビア大学教育学大学院で運動科学と運動学を教えるキャロル・ユーイング・ガーバー教授は、「ホットヨガでは、熱の効果で実際よりも体が柔らかいような感覚になるために、体の可動域を超えた動きをしてしまい、結果として筋肉と関節を痛める、というのが最も一般的です。しかしケガに関するデータもまた、限られた条件のもとに集められたものです。研究は、十分に訓練を受けた質の高いヨガ講師と共にベストな環境で行われています。なので、研究を参考にする場合には少し注意が必要です。研究と離れた現実の世界では、トレーニングの内容もインストラクターごとに多くのばらつきがあります。」とコメントしました。


Research on one form of hot yoga, Bikram yoga, suggests it improves balance, lower body strength and range of motion for both the upper and lower body, and might even help improve arterial stiffness and metabolic measures like glucose tolerance and cholesterol levels, as well as bone density and perceived stress. But the Australian researchers who reviewed the literature — including one who is a co-owner of a Bikram yoga studio — noted that only one randomized controlled trial, the kind considered the gold standard in medicine, had been conducted, and that most studies did not track adverse events and included only healthy adults.




If you have low blood pressure or a pre-existing health condition, consult with a doctor before trying hot yoga. If you have adverse reactions to heat, are prone to heat stroke or dehydration or have a medical reason to avoid being in a hot tub or sauna, you may want to stick with regular yoga. If you are doing a hot yoga class, make sure you’re well hydrated by drinking a lot of water before, during and after class.




“If you’re sweating profusely, it’s very difficult to replenish that fluid,” Dr. Garber said, and many people aren’t good at “recognizing the early signs of heat illness.” These include thirst, profuse sweating, dizziness or headaches, weakness, muscle cramps and nausea or vomiting.





※ランダム化比較試験RCT:Randomized Controlled Trial)