A new study has found that braving the cold may be a good way to help burn off some of that Christmas pudding. The sample size may be small, but the research suggests the ambient temperature while exercising can have an effect on fat metabolism.
The research was carried out by scientists at Canada’s Laurentian University and focused on high-intensity interval training (HIIT), where short and intense exercise is interspersed with lower-intensity bouts. This format has grown in popularity of late due to the fat-burning benefits it brings, and the team set out to explore how ambient temperature might influence its effects.
More specifically, the team points to previous research demonstrating how HIIT workouts are better for lipid metabolism, or the breakdown and storage of fats, and the fact that ambient temperature is a factor in metabolism during exercise and rest. This led them to draw up a study investigating how HIIT, metabolism and ambient temperature may be related.
The study involved 11 “recreationally active” but overweight adults who took part in two HIIT sessions a week apart. One of these was carried out in a “thermoneutral” environment with temperatures of around 70 °F (21 °C), and the other at a frigid 32 °F (0 °C). The sesssions consisted of 10 separate cycling sprints at 90 percent effort lasting one minute apiece, followed by 90-second "recovery" periods of cycling at 30 percent intensity.
After each session, the participants cooled down by gently cycling or walking, ate a nutrition bar before going to sleep and indulged in a high-fat breakfast the morning after. During these sessions, the scientists monitored skin temperature, core body temperature, heart rate and the amount of oxygen delivered to the thighs, along with glucose, general oxygen, carbon dioxide levels and gas exchange levels. Blood samples were also drawn to help calculate lipid oxidation, or fat burning, rates following the breakfast the next day.
“The present study found that high-intensity exercise in the cold increased lipid oxidation by 358 percent during the exercise bout in comparison to high-intensity exercise in a thermoneutral environment,” the team writes.
The authors note that the cold conditioning had a negligible effect on the longer term metabolic responses, including blood sugar regulation, fat burning and triglyceride levels, once the high fat meal was consumed the next morning. Moreover, with such a small group of participants and data only taken from two HIIT workouts, the idea that cold temperatures help us burn more fat during exercise will need further investigation, though the first-of-a-kind study does indicate it's a possibility worth pursuing.
The research was published in the Journal of Applied Physiology.
Source: American Physiological Society