High-intensity interval training (HIIT) is a type of training based on short bursts of activity which are mixed with rest periods. Latest research shows it is your best pick when it comes to using exercise to combat the cellular signs of ageing.
In this study, HIIT beat weight training for boosting cells’ mitochondrialactivity – the chemical reactions that release energy and fuels cell growth. This activity usually declines with age, but HIIT was shown to actually reverse it in some cases.
That is helping us understand more about limiting disabilities and diseases such as diabetes as people get older, according to researchers from the Mayo Clinic in Minnesota, even if it can’t help you live forever just yet.
Although the study only involved a relatively small sample size of 72 volunteers, the results are impressive enough to be significant as scientists say.
“These things we are seeing cannot be done by any medicine,” says researcher Sreekumaran Nair.
“Based on everything we know, there’s no substitute for these exercise programs when it comes to delaying the ageing process.”
Researchers enlisted the help of 36 men and 36 women split across two age groups; a ‘young’ group aged 18 to 30, and an ‘old’ group aged 65 to 80.
The researchers put the volunteers into three mixed-age groups: one group was doing high-intensity interval training on bikes; one group did weight training; and one group was doing a combination of the two, for a period of 12 weeks.
The HIIT program involved three days in a week of cycling, with high-intensity spells of pedalling split up by less intensive peri+ods, plus two days a week of treadmill work.
Then the muscle cell make-up, muscle mass, and insulin sensitivity were analysed and compared with a control group that did no exercise at all.
HIIT produced the biggest benefits at the molecular level, with the younger participants on HIIT showing a 49 percent increase in mitochondrial capacity, and the older participants on HIIT reaching a 69 increase on average.
The cells of the older volunteers started generating energy at a rate comparable to cells from much younger bodies, in other words.
Mitochondria act like energy factories for our cells, converting glucose into power for our bodies at the lowest levels, but as we get older this process starts to slow down. This leads to cell damage and dysfunction we associate with ageing.
Scientists yet don’t fully understand how this all works, but starting more mitochondrial activity through exercise could be one way of keeping many of the signs of ageing at bay.
While it was well-established that exercise is good for the body, scientists are still figuring out the changes it makes at the molecular level.
The researchers say the regeneration of muscle protein which was shown in this study could also be replicated in the heart and brain, the other areas of the body where cells wear out more easily as we get older.
HIIT improved insulin sensitivity levels too, which reduces the risk of diabetes, though it wasn’t as effective as weight training at building up muscle mass. And any kind of exercise was shown to be better than doing nothing at all.
“If people have to pick one exercise, I would recommend high-intensity interval training, but I think it would be more beneficial if they could do three to four days of interval training and then a couple days of strength training,” says Nair.