QUESTION from a LONG-TIME LISTENER: “Hello once again! I'm writing to you as a group fitness instructor going through a yoga certification. In our training we've discussed the various expected room temperatures for different types of yoga, ranging from 90 to 110 degrees! My question is – what does the sports science research say about the optimal temperature for different types of workouts?
Whether it be yoga, weight training, or cardio interval. They also offer a yoga-cardio hybrid class that is recommended to be at 85 degrees. I want to make sure that I set my future students up to be successful in their workouts and creating the physical environment is a big piece of that. As always, I really appreciate your thorough research, helping me and so many others become more in tune with our bodies. Thanks.”
DR. NEAL: Thank you for your question. At first, I thought answering this question would be super-easy.
I remember that, at some point, I learned that cooler temperatures are better for working out – especially if you’re doing cardio. Specifically, I remember hearing that cooler temperatures allowed you to run, bicycle, row, and climb faster and longer.
But when I started searching for research articles that talked about ideal ambient temperatures for exercise, they were really difficult to find!
The Colder, The Better?
I was able to find numerous sources all quoting the same exercise physiologist saying that an ambient temperature of 70 degrees Fahrenheit (or about 21 degrees Centigrade) is ideal. But I couldn’t find where this person was getting this information from.
I was able to find a study that compared different temperatures on muscle fatigue. The researchers had athletes work out in a cold temperature, which they defined as 37 degrees Fahrenheit (or, 3 degrees Centigrade), a neutral temperature defined as 68 degrees Fahrenheit (20 degrees Centigrade), or in hot temperatures, 104 degrees Fahrenheit (40 degrees Centigrade).
They found that their athletes performed best at… can you guess? The coldest temperature condition – the 37 degrees Fahrenheit (3 degrees Centigrade)! I was surprised, too. I thought they would perform best at 68 degrees Fahrenheit (40 degrees Centigrade).
Now, you’re probably thinking… “Why??” Well, the researchers actually tracked how much stored sugar (also known as glycogen) their athletes used for energy in each of these situations. They found that when the athletes worked out in warmer temperatures, their bodies used more stored sugar as energy. But when exercising in colder temperatures, their bodies didn’t use as much glycogen.
The authors believe that, somehow, colder temperatures may trigger the body to slow down the rate at it burns through its energy stores. Meaning, the more slowly we burn fuel, the longer and more intensely we’ll be able to work out.
What About “Warm-Ups”, Then?
Does this mean that your gym should keep the temperature close to freezing? No.
Here’s something else we need to think about: don’t I always talk about how important it is to warm-up your muscles? Why would warming-up and keeping a gym cold be helpful? Those seem like exact opposites!
Well, here’s what’s going on: when we’re trying to perform endurance exercises, like cardio working out in a colder environment may help you work out longer. This means you would still want to perform a full warm-up to lower chances of getting injured and getting your body ready for the workout.
So, what’s up with all the “hot yoga” classes and all the stuff you’ve heard about heat and flexibility? Well, that’s exactly where heat can be helpful – for flexibility.
Studies have found that heat can increase muscle and tendon flexibility. So when you’re stretching, you may want to keep the room a bit warmer. Or you could always put your sweatshirt and sweatpants back on after your workout to keep those muscles warm.
Ideal Workout Temperature: The Bottom Line
Here’s the bottom line:
When performing endurance-type exercises like running, bicycling, rowing, climbing and so on, try and keep the temperature on the cooler side. How cold does it have to be? We still don’t know for sure, but the colder the better – so long as it’s safe to do so, of course.
You wouldn’t want to put yourself at-risk for harm by working out in sub-freezing temperatures just because you think you’ll achieve a new personal record. Personally, I love working out on that one day a year we get here in southern California when the daytime temperature reaches 60 degrees Fahrenheit (about 16 degrees Centigrade).
When it comes time to work on your flexibility, think warmth. Whether you achieve this by wearing more layers or heating up the ambient temperature, warmth may help keep your muscles and tendons more flexible, allowing you to achieve that deeper stretch.