Falling off track from your workout routine is inevitable. Life happens. You go on a trip. You sprain your ankle or start a new job. Then, once you find the time to resume training, you feel weak and out of breath. It can seem like all your good work has been for nothing. But that isn’t the case.
Although we do lose fitness shockingly fast, it turns out that we don’t simply go back to square one. What’s more, even when circumstances keep you from your regular routine, there are various things you can do to minimise the losses.
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This article is part of a series on fitness that answers eight questions about exercise and its influence on our bodies and minds. Read more here.
How rapidly fitness declines depends on what aspect of it you consider. The news is worst when it comes to aerobic fitness. Evidence suggests that VO2 max, the maximum rate at which the body can absorb oxygen, drops significantly after a , largely due to a roughly 10 per cent decrease in the amount of blood your heart can pump with each beat.
Some changes occur even sooner. For instance, blood volume decreases after two days of rest. After a month, we have fewer capillaries delivering oxygen to our muscles too, possibly due to changes in levels of a .
Out of breath
In a from June, at the Norwegian School of Sports Sciences and his colleagues found that improvements in VO2 max from two months of training evaporated after three months of inactivity. “With aerobic fitness, if you don’t train for months, you lose it, and it is like starting over almost every time,” says at the University of Michigan.
Muscles are a tad more resilient to inactivity. Notable declines in strength occur within around two to three months of stopping exercise. Research shows that eight weeks without training can of a 12 per cent decrease in strength.
Changes may happen even faster, though. Another study in people aged around 70 found that participants lost, on average, after decreasing their daily step count by 75 per cent for two weeks. And some of the knock-on benefits of fitness were reduced too: participants became more resistant to insulin, which controls blood sugar levels, and had higher levels of unhelpful immune activity called systemic inflammation.
Muscle memory
However, thanks to a , all is not lost. Sharples and his colleagues found that that make muscle proteins, and that these genetic changes can endure for months after training stops. Participants in a 2018 study saw a 7 per cent increase in muscle mass after seven weeks of resistance training.
These gains mostly disappeared once they stopped training for seven weeks. Yet their muscle mass grew by 12.5 per cent, on average, after an additional seven weeks of resistance training. This suggests that “muscle might remember [previous training] and get back those [lost] gains more quickly than if you had never experienced them before”, says Sharples.
Admittedly, many of these studies include only a few participants – the 2018 one, for example, involved just eight people, all men. But they may also represent worst-case scenarios because they tend to explore what happens when people stop training entirely.
The picture is probably different if you just decrease your exercise. “If you can keep the intensity of your workouts, even if you have to cut your volume by 50 per cent, you can minimise your fitness losses,” says at the University of Glasgow, UK.
And even if you can’t find time for conventional exercise, maintaining any level of activity will help. For example, a found that vigorously climbing stairs for 20 seconds, three times daily on three days of the week improved participants’ VO2 max by about 5 per cent, on average, after six weeks.
Exercise snacks
With this in mind, Lane recommends incorporating short bouts of movement – what she calls “exercise snacks” – into your day. “Anything you can do counts, so find ways to be creative, whether it is running for the bus, doing yard work or playing in the pool with your kids,” she says.
The key is to use your muscles in any capacity that works for you. So, if you are injured, it is best to seek advice from a physical therapist who can recommend appropriate, lower-impact exercises such as swimming or cycling.
On an even more positive note, you may be able to mitigate fitness declines with a simple dietary intervention, as there is evidence that due to immobilisation. This is no substitute for exercise, but it might give you a helping hand when life gets in the way.
