Want to burn fat? New research tells that exercising in lower temperatures could burn off more fat than normal–at least for short bursts of high-intensity exercise.
A study conducted on 11 “moderately fit, overweight” adult volunteers, lipid oxidation (the technical term for burning fat) increased by over three times during exercise in a colder environment of 32 degrees Fahrenheit (zero degrees Celsius), compared with a “thermoneutral” environment of around 70 degrees Fahrenheit (21 degrees Celsius).
The participants performed a set of standard workouts for high-intensity interval exercise (HIIE), also known as high-intensity interval training (HIIT), at each temperature: Ten 1-minute cycling sprints at 90 percent effort, followed by 90-second recovery periods of cycling at 30 percent effort, with a cool-down period at the end of both sessions.
Researchers from Laurentian University in Canada in their paper said that this was the first research during high-intensity interval exercise, and postprandial metabolism the next day investigated the effects of cold temperatures on acute metabolism.
They observed that high-intensity interval exercise in a cold environment changes acute metabolism compared to a thermoneutral environment, but the addition of a cold stimulus was less favourable for postprandial metabolic responses the following day.
Our body is better able to process nutrients and regular lipid or fat levels in the blood when it gets active. Thus, to study the effect researchers measured skin temperature, core body temperature, heart rate, and the amount of oxygen delivered to the quadriceps muscles.
The next morning, after a high-fat breakfast, blood samples were taken to check on insulin, glucose, and triglyceride levels in order to figure out lipid oxidation rates again and to check if the benefits of the previous night had carried over.
Exercise in cold increased lipid oxidation by 358% immediately afterwards, but there was no huge difference following breakfast the next morning (the “postprandial” period). Glycemic response which is the change in the body’s blood sugar levels after eating was better after exercise in the thermoneutral environment as per the readings.
Researchers concluded that even though acute benefits seem to be present during acute HIIE in the cold, postprandial metabolic responses were less favourable when high-intensity interval exercises were performed with acute cold exposure.
It is too early to draw a conclusion based on this, as there were only a few volunteers and only about a couple of HIIE sessions were done. But it is still an interesting start for looking at how ambient temperature might affect fat burning during bursts of intensive exercise.
Previous studies have shown that HIIE is very effective at burning off fat–which is part of its appeal–and there’s also an established link between body metabolism after exercise and how hot or cold the environment is. The new study combines those two fields, thus giving us an extra edge in knowing how crucial doing exercise is and which exercises help us.
Stephanie Munten, Lucie Ménard, Jeffrey Gagnon, Sandra C. Dorman, Ania Mezouari, and Dominique D. Gagnon High-intensity interval exercise in the cold regulates acute and postprandial metabolism Journal of Applied Physiology (2020) DOI: 10.1152/japplphysiol.00384.2020