After study data was released by Scotland's University of Aberdeen at the start of the new year, lifestyle and health reporter Sarah Berry concluded that "the temperature during exercise also affects our appetite and how we are likely to eat once we've worked out."
In Australia, the information is timely, as residents are immersed in the intense heat of the southern summer after the heavy food consumption typically associated with Christmas and New Year celebrations.
Ms Berry mentioned previous research that showed that exercise does not merely get our appetites going, but humans also display a propensity to stack on the calories as a reward or compensation for the intensive physical activity. The phenomenon is identified as the underlying cause for why some people's fat levels grow after they incorporate exercise into their lifestyles.
The Scottish researchers explained their study methods in their January 2015 abstract:
"Sixteen overweight participants (10 men and six women ...) completed a 45-min treadmill walk at 8°C and 20°C ... Participants were presented with an ad libitum buffet meal 45 min after exercise, and EI [(energy intake)] was covertly measured."
Both internal and surface temperatures were measured, while the participants' levels of appetite hormones, like ghrelin, were also examined.
The University of Aberdeen found that the research subjects did not burn more calories while exercising in cold conditions, while they burned more calories when the heat was intensified—in accordance with what the researchers expected, the human body works harder to avoid overheating. Additionally, those who were active in the cold, were much more hungrier afterward and consequently ingested larger quantities of carbohydrates.
Using these new results, taken from a study that is relatively small in size, Ms Berry spoke with Associate Professor Corinne Caillaud, from the University of Sydney, who said that both hot and cold environments offer benefits for exercisers. Ms Caillaud explained that different temperatures influence our metabolisms in various ways, and the "way we adapt is different depending on the humidity". The academic's foremost point is that people "have to be careful" in both environments.