When it comes to getting stronger, how often you exercise is more important than how hard you push yourself.
A study has found people see bigger gains in muscle strength if they spread their workouts over a week instead of cramming it into one day.
Two groups did the exact same number of bicep curls using the heaviest dumbbells they could, one over five days and another in one day.
Those who did more frequent weight training saw their muscle strength increase by around 10 per cent in four weeks.
While the once-a-week group did not see any strength gains, their muscle thickness increased by a third more.
Lead researcher Professor Ken Nosaka, director of exercise and sport science at Edith Cowan University in Perth, Australia, said: ‘People think they have to do a lengthy session of resistance training in the gym, but that’s not the case.
‘Just lowering a heavy dumbbell slowly once or six times a day is enough.’
A study has found people see bigger gains in muscle strength if they spread their workouts over a week instead of cramming it into one day. Two groups did the exact same number of exercises, one over five days and another in one day
Researchers recruited 36 student volunteers in their early twenties from Niigata University in Japan.
They were split into three groups and told to perform ‘maximal voluntary eccentric bicep contractions’ with their preferred arm.
The arm resistance exercise consisted of lowering the heaviest dumbbell they could in a bicep curl.
They did this while attached to a special chair that measures the strength in each muscle used for the exercise.
One group did six contractions per day for five days a week, another did 30 reps once per week, while the third group performed six contractions once per week.
Changes in muscle strength and thickness were measured and compared four weeks later.
The findings are published in the Scandinavian Journal of Medicine and Science in Sports.
Those who did 30 reps in one day did not see any change in muscle strength but their muscle thickness increased 5.8 per cent.
HOW MUCH EXERCISE SHOULD I DO?
Adults aged 19 to 64 are advised to exercise daily.
The NHS says Britons should do at least 150 minutes of moderate intensity activity a week, or 75 minutes of vigorous intensity a week.
The advice is the same for disabled adults, pregnant women and new mothers.
Exercising just one or twice a week can reduce the risk of heart disease or stroke.
Moderate activity includes brisk walking, water aerobics, riding a bike, dancing, doubles tennis, pushing a lawn mower, hiking and rollerblading.
Vigorous exercise includes running, swimming, riding a bike fast or on hills, walking up stairs, as well as sports such as football, rugby, netball and hockey.
Those who did six contractions once a week did not see any change to their muscle size or thickness.
But those who spread out their activity saw their muscle strength boosted by 10 per cent and a 4.4 per cent growth in muscle size.
There has long been debate about the best way to train for those working to get stronger compared to those trying to get bigger muscles.
Researchers don’t yet know why small doses of resistance exercises are more effective than doing it less often.
It may be to do with how often the brain is asked to make a muscle perform an exercise, they said.
Improvements in muscle strength in the early phase of resistance training has been linked to better coordination when repeating movements over time.
Therefore, those doing workouts less frequently may not be performing the exercise as well, the team suggests.
Professor Nosaka said while the participants used the heaviest weight they could in the study, separate research suggests people could get similarly strong without pushing themselves as hard.
He added: ‘We only used the bicep curl exercise in this study, but we believe this would be the case for other muscles also, at least to some extent.
‘Muscle strength is important to our health. This could help prevent a decrease in muscle mass and strength with ageing.
‘A decrease in muscle mass is a cause of many chronic disease such as cardiovascular disease, type 2 diabetes, some cancers, dementia, plus musculoskeletal problems, such as osteoporosis.’
Current national exercise guidelines in the UK, US and Australia set out the number of minutes people should workout per week. Britons and Americans are advised to do 150 minutes per week, while Australians are told to do 150 to 300 minutes.
The researchers called for more focus on daily activity.
Professor Nosaka said: ‘If you’re just going to the gym once a week, it’s not as effective as doing a bit of exercise every day at home.
‘This research, together with our previous study, suggests the importance of accumulating a small amount of exercise a week, than just spending hours exercising once a week.
‘We need to know that every muscle contraction counts, and it’s how regularly you perform them that counts.’
However, the team emphasised the importance of rest days — as that is when changes to muscle occur.
Professor Nosaka said: ‘If someone was able to somehow train 24 hours a day, there would actually be no improvement at all.
‘Muscles need rest to improve their strength and their muscle mass, but muscles appear to like to be stimulated more frequently.’
And if someone was unable to exercise for days or weeks, such as due to illness, there is ‘no value’ in trying to ‘make up’ for it with extra sessions.
Researchers from Nishi Kyushu University in Japan also collaborated on the study.