||Fri, Dec-04-20 10:25
The surprising health benefits of exercising in the cold
The surprising health benefits of exercising in the cold
We all know the advantages of exercise, but embracing the winter chill can notch it up a level – the experts explain how
As winter descends it is tempting to wrap up warm and hide indoors, but hibernating could deprive you of a host of cold-related health benefits. Scientists believe that regular exposure to the cold can help to torch fat, raise your metabolism, prevent diabetes, fine-tune your heart and lungs and even fight depression.
Exercising outside on cold days also appears to deliver some bonus performance benefits: research suggests cyclists can ride 42 per cent longer in temperatures of 3°C than in balmy 20°C conditions, elite footballers run further at 5°C than at 21°C, and marathon runners clock their fastest times when it’s a nippy 3.8-9.9°C.
According to Dr Cara Ocobock, director of the Human Energetics Lab at the University of Notre Dame, as long as you warm up to prevent injuries and allow your lungs to adjust to the cold air, winter can be a rewarding season for runners and cyclists. Whatever time of year you exercise, your body produces a huge amount of heat – around 20-25 times your resting metabolic heat. So on hot days, your body has to work extra hard to keep cool. But on cold days, your body is less stressed, so you have more energy for training.
“Once things are up and running – pun totally intended – it seems that athletes can push themselves a bit harder in the cold because their bodies don’t warm up as much,” explains Ocobock. “There is less risk of overheating so they can get a bit of a performance boost.”
Cold exposure can also strengthen your heart and lungs. When you get cold, your heart rate rises, your blood vessels constrict, your breath is quickened, and oxygen is sent to your muscles. These physiological processes challenge and fine-tune your cardiovascular system. According to Prof Wouter van Marken Lichtenbelt of Maastricht University Medical Centre, a little cold a day keeps the doctor away: “Temperature training by regular exposure to mild cold keeps the peripheral vascular system in motion – for example, vasoconstriction during cold and vasodilation during heat – and thereby helps to train the cardiovascular system.”
But you don’t have to do any frosty jogs to enjoy cold-related rewards. Studies suggest that simple daily exposure, such as going on cold lunchtime walks, turning the thermostat down a few degrees, wearing one less layer of clothing, cracking open a window, sleeping in a cooler room or having cold showers can trigger amazing benefits. Winter hikes burn 34 per cent more calories. Sleeping in a cool bedroom raises your metabolism by 10 per cent. Even mild cold exposure – two hours a day at 19°C for six weeks – can cut body fat by 5.2 per cent.
Many of these health benefits relate to a mysterious substance called ‘brown fat’, which is located around your neck, collarbones and spine. Whereas normal ‘white fat’ stores energy from food, brown fat burns energy for heat. “One of the ‘selling pitches’ for brown fat is that it is ‘the fat that makes you thin,’” explains Prof Michael Symonds, deputy head of the University of Nottingham School of Medicine. “Brown fat has this unique molecule protein within its mitochondria called uncoupling protein. When it is activated by cold exposure, it can – because of its biochemistry – rapidly produce large amounts of heat. A gram of brown fat will produce 300 times more heat than a gram of any other tissue in the body when maximally stimulated.”
To produce this heat, brown fat burns glucose (sugars) and lipids (fats), which is why cold exposure appears to improve body composition and blood sugar levels. Research suggests that following exposure to the cold, subjects experience lower levels of circulating fatty acids and triglycerides, which are linked to heart disease. “Anything that makes you cold will stimulate your brown fat, and that should be beneficial in terms of keeping your weight down, minimising fat deposition and improving glucose regulation,” explains Symonds.
Van Marken Lichtenbelt’s team believes that cold exposure could be a useful ally in the fight against obesity and diabetes. That’s because getting cold, but not uncomfortably so, boosts non-shivering thermogenesis (NST) – a cold-induced spike in your calorie-burning metabolism – by up to 30 per cent. In one study, when diabetics turned the thermostat down to 15-19°C for a few hours a day, they gained a 43% improvement in insulin sensitivity.
As these adaptations are triggered by your body getting cold, they won’t all be activated if you do high-intensity exercise outside. “The physical activity will produce heat that will keep you warm,” explains Ocobock. But simply wearing one less layer during the day or enjoying winter walks around the park could yield rich rewards: Ray Cronise, a former NASA material scientist turned health guru, claims to have lost 13kg by going on “shiver walks.”
However, winter runs, swims and bike rides will deliver additional performance, cardiovascular and aerobic benefits, and burn more calories too. Ocobock’s research suggests winter conditions – like snow, fierce headwinds and sticky mud – are more metabolically demanding, which is why winter activities have a higher calorie burn.
Winter exercise also delivers a powerful mental health boost: when you get cold, your body releases the mood-enhancing hormones beta-endorphin and noradrenaline, which can help to ward off the winter blues. And the lack of humidity during winter, which is what gives you that heavy, lethargic feeling over summer, enhances clarity of mind. New research even suggests cold water swimming could protect against dementia.
There are obvious limits to the benefits of winter exercise: anyone with heart problems should avoid cold shock, and there is nothing healthy about hypothermia. But Ocobock’s studies of Finnish reindeer herders suggest we can all enjoy healthy adaptations to the cold if we get out more. Cold climate populations tend to benefit from an elevated metabolic rate, more brown fat and an enhanced vasoconstriction and vasodilation oscillation, known as the ‘hunting response’, which helps to reduce heat loss while protecting the extremities.
“Temperate folks can increase their metabolic rate and likely their brown adipose tissue (BAT) if they expose themselves to cold more regularly,” concludes Ocobock. “Sleep with a window open and fewer blankets, turn down the thermostat – those kinds of things.”
So whether you’re boosting your heart with a chilly jog, activating your brown fat with a cold lunchtime walk, or spiking your metabolism by turning down your thermostat at home, it’s good to embrace the winter chill.
“When the winter is coming, don’t be put off,” insists Symonds. “This is a really good opportunity to get your brown fat going.”