Last year, I met a personal trainer who told me he believes that HIIT causes premature signs of ageing. He trains celebrities and knows that when a star needs to get in shape for a job in a short time frame, HIIT is the answer. However, for the general public, he felt that hitting up a HIIT class too often could be detrimental. This idea really stuck with me, so I decided to ask two other industry experts—Doug Tannahill (head of clinic at the Centre for Health and Human Performance, and head of strength and conditioning at BXR London), and Zac Taylor (fitness director at PB Wellbeing)—to answer the question at hand: Can the same HIIT classes that have been found to strip fat and boost cardio levels in ultra-quick time actually be ageing our bodies and even our complexions?
That your HIIT class could potentially be ageing isn't all that far-fetched. Running has been associated with early onset skin wrinkling and sagging known as "runner's face," although you need to pound the pavements for a long time to really see any complexion-based consequences.
In fact, a few years back, I ran two marathons and had a run streak that involved me running at least a mile a day for 500 days. I got ID'd last week buying superglue, and I'm pretty sure you only need to be over 18 to buy it. (I'm 33 next month.) "You might possibly notice some skin and body ageing if you're training for a marathon, Ironman or triathlon where training is relentless," says Taylor.
But could HIIT, which involves short, sharp intervals, speed up the ageing process? Taylor isn't so sure. Neither is Tannahill: "You could argue that with increased mechanical loading on the skin, there may be some change in its structure, like collagen and elastin breakdown. However, you need to take a step back and look at this from another point of view.
"Studies have shown that there's improvement in mitochondrial density in muscle cells, which improves the cells' overall energy-producing capacity, meaning your cells are happier and healthier. Should age only be thought of in terms of the wrinkles on your skin, or is it better demonstrated by your body's ability to function and thrive on a day-to-day basis?"
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When it comes to your body, HIIT can do amazing things. "If utilised correctly and appropriately, it can help your body to develop and maintain many qualities associated with being 'younger,'" says Tannahill. "Stronger muscles, better cardiovascular capacity, improved balance and increased insulin sensitivity. Ultimately these qualities are those that keep the body injury- and pain-free."
"Of course HIIT is just like any other form of exercise—there's a potential for injury," Tannahill continues. And it isn't for everyone. Taylor says he wouldn't advise HIIT for anyone overweight or new to working out. "You want to start with steady cardio and conditioning, and then build up," he says.
"HIIT workouts are intense, so you shouldn't be doing them a long time. If you go on too long, your body may break down, which may cause injury," warns Taylor. And injuries can cause age-related issues in the long-term, such as post-traumatic arthritis, so as with any exercise, you should be careful.
The benefits seem to outweigh the possible negatives. "It's a full-body workout—you're hitting the visceral fat (the fats you don't see inside your body, around internal organs); you burn fat, not muscle; you can fit a HIIT workout into your lunch hour; you burn calories quickly, which increases the metabolism; you can do it anywhere; and you don't need any equipment. There are also lots of different exercises, so you shouldn't get bored," says Taylor.
In short, it looks like HIIT can actually help keep your body young. If you do a lot of vigorous exercise and you're worried it could be ageing your complexion, you should try these four body stretches that actually make your face look younger.