Last month I subbed a couple of hot yoga classes. Confession: I am not a fan of hot yoga, as a teacher or a student. In addition to being hard on the environment (think of how much energy we use to artificially heat a room--thanks to one of my favorite teachers, Wendy Green, for instilling that in me!), hot yoga can be downright dangerous if you're not prepared. Some studios crank the heat above 100 degrees--and increase the humidity, too. (You want hot yoga, just come to Cincinnati!)

At the studio where I practice, the temperature frequently tops 85 degrees in summertime--that's with minimal air conditioning. If you pack a room full of people who are moving, sweating, and breathing, you'll create heat.

By the end of a practice, the windows are foggy, we're all soaked through, and our mats are dripping with sweat. That's my kind of hot yoga!

Hot yoga is a hot trend in the practice these days. Almost every studio offers a hot class of some variety, from Bikram to Moksha, vinyasa to yin. (One of the studio owners I work for confessed to me that she doesn't like or believe in hot yoga, but it's what students have requested.) And in summertime, almost every yoga practice can feel like a hot one.

Why hot yoga? Advocates say hot yoga facilitates stretching, increases range of motion, removes toxins, and promotes weight loss. It's true that it is easier to stretch warm muscles (and you should never stretch "cold" muscles), but whether hot yoga will lead to greater weight loss depends on the type of yoga you're practicing.

According to the American Council on Exercise, Hatha yoga (in the West, this has come to refer to slower-paced classes) burns about 150 calories an hour (and does not raise your heart rate enough to be considered a form of cardio), while vinyasa (faster-paced, flowing yoga) burns about twice that much. If you're losing pounds after each hot yoga class, it's likely water weight. (More on that later.)

Whether you practice naturally hot yoga as I do or practice at a studio that cranks up the heat, you'll want to be safe. (You might also want to read: "I Tried Hot Yoga" before you take a class.) Here are some tips to help:  

1. Be safe. Decide if it's right for you. Hot yoga is unsafe for anyone who is pregnant, a child, over the age of 60 (without a regular yoga practice), or suffering from medical conditions that would make it unsafe to exercise. If you have diabetes, any issues with high or low blood pressure, or are prone to dizzy spells, choose another type of yoga class.
    
2. Go au natural. Though it seems counterintuitive to shower before a workout, I often rinse off before yoga practice to remove any lotions or oils that will make my skin even more slippery once my body starts to sweat. There's nothing more frustrating than finally nailing an arm balance, only to slide right out of it because of lotioned-up skin!  (Also: skip the scents. The only thing worse than being stuck on a mat next to a stinky person is practicing on a mat next to a person who's drenched in perfume or cologne. Reapply deodorant before class if you're self-conscious, but skip the perfume, the smell of which can be overwhelming in heated, humid rooms.)
    
3. Invest in a chamois or a yoga towel. All that sweat turns your usually sticky yoga mat into a slip-and-slide. While you can use a regular towel (try a beach towel for maximum coverage), if you practice regularly, consider investing in a yoga towel, which is made of microfibers that absorb moisture and become grippy when wet. (I especially like Manduka towels, which last for years and are worth every penny.) Some, such as YogiToes, also have silicone beads for added stickiness. A travel yoga mat, such as those from Gaiam, also works well as a mat cover. If you tend to sweat profusely, Manduka makes yoga "rugs," too. Take a hand towel, too, if your studio doesn't provide them. In addition to mopping sweaty brows, a quick swipe of the towel up and down your limbs can make many poses more manageable.
    
4. Respect your edge. In yoga, we encourage our students to relax and let their bodies ease into a pose. When our muscles are warm, it's easier to stretch them, which means that suddenly body parts find it a little easier to say "How do ya do?" Knees meet nose, fingertips touch toes, and arms clasp behind the back with more ease when you're warm. Whether you're trying to bind in twisting pose or just reach a centimeter farther in a forward fold, don't push too hard. Move slowly and mindfully to a point where your muscles feel challenged, breathing all the while! Never stretch to the point of pain--and never bounce as you stretch.
    
5. Take a rest. If you feel lightheaded, dizzy or otherwise ill at any point during the practice, take a break. Sit down on your mat, go into child's pose, or step out of the room. (Note: Some teachers lock the door or refuse to let students leave the room after class has begun. While it is not good manners to saunter in and out of a yoga studio during class, when you're sick or really need to use the bathroom, it's fine to leave--just be discreet. Sure, you might let a little heat escape the room, but passing out in the middle of tree pose would surely cause a bigger interruption!)
    
6. Drink up. In yoga, we traditionally drink water before and especially after a class. The traditional belief is that our yoga practice builds heat, and water extinguishes it. Some hot yoga classes have designated water breaks, and I've heard stories of yoga teachers who scold students for even looking at their water bottles during class. While you might not want to chug water after every sun salutation, a few sips of water as needed are fine. Save the water guzzling for after class, if only because you'll feel uncomfortable trying to twist and stretch with a belly of water. And trying to practice yoga with a full bladder? Uncomfortable! Drink one to two cups of water 30 to 60 minutes before practice, then…
    
7. Keep drinking. You lose as much as 32 ounces of water for every 60 minutes of exercise. Immediately after exercise, drink at least twice that much--especially if you've not been drinking much water during your yoga practice. If your practice lasted more than an hour, consider consuming a sports drink in addition to regular water to replenish carbohydrates and electrolytes. NOTE: If you feel lightheaded or uncoordinated (more than usual!) or have muscle cramps, consider these to be signs of dehydration. (Learn more about water needs during exercise.)
    
8. Eat right. As with any physical activity, you'll want to make sure you're eating right to help you perform your best. While a snack or light meal an hour or so before working out is recommended, you might want to allow two hours between any snacks and four meals between any heavy meals and your yoga practice. If you thought practicing with a belly full of water was uncomfortable, try practicing with a belly full of food. Ugh! And if you can, save foods that are spicy or those that tend to give you gas or cause bloating for after class. You'll want to eat a snack or meal that contains both protein and carbohydrates within an hour of finishing your practice.   
9. Listen to your body. Only you know how far you can comfortably push your body. Listen to those signs that your body offers you. Don't feel the need to "keep going" in a pose if the intro level is enough of a stretch and challenge for you. Your yoga practice is yours and yours alone. Quiet the ego--that little voice that tells you to push harder when you know you could risk injury--and just breathe and enjoy being where you are now.
    
10. Dress for it. Hot yoga is not the time to be modest. No one is there to judge you, and no one looks his or her best when dripping in sweat. Wear tight-fitting clothes, as looser garments trap heat. Some people prefer to wear pants or capris so they absorb the sweat and keep it off your mat; I would much rather have the sweat on my mat than have sweaty clothes covering any more of my body than is necessary! Tank tops are a great choice, as they allow for better range of motion and generally stay in place better than a T-shirt. I highly advise you against wearing regular cotton clothing. Once drenched in sweat, it will feel heavy and clammy against your skin. A moisture-wicking headband (I like Bondi Bands) is a must for keeping sweat from dripping in your eyes. That's a surefire way to break your concentration!

Whether you're doing yoga in a heated studio or in the great outdoors, these tips can ensure a safe and comfortable practice.

Do you practice hot yoga? What is your best tip for staying hydrated and healthy?