How often do we really need to exercise?

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  • For years, it hasn’t been clear whether it’s better to do a little exercise every day or a lot a few times a week.
  • It seems like a little bit of daily exercise can be more beneficial than longer periods throughout the week.
  • This is according to the results of a new study, although it was based on muscle strength only.

We know we need to exercise to stay healthy. While the health benefits of exercise on the brain and body are clear, researchers have for years debated the frequency and duration of workouts in order for us to see these benefits.

A new study suggests that a little bit of daily exercise is more beneficial than longer periods of activity spread out across the week - at least for muscle strength.

The researchers from Edith Cowan University in Australia, and Niigata University and Nishikyushu University in Japan, say that people don’t need to put in a “mountain” of effort every day. 

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"People think they have to do a lengthy session of resistance training in the gym, but that's not the case," co-author and ECU Exercise and Sports Science Professor, Ken Nosaka, said in a news release.

"We need to know that every muscle contraction counts, and it's how regularly you perform them that counts. Just lowering a heavy dumbbell slowly once or six times a day is enough," he added.

Carrying out the study

The team created a four-week training study and recruited three groups of participants who performed an arm-resistance exercise.

Two groups performed 30 contractions per week - of these groups, one did six contractions per day for five days a week (6x5 group), while the other crammed all 30 into a single day, once a week (30x1 group).

The third group only performed six contractions, one day a week.

To chart results, the researchers measured and compared changes in muscle strength and muscle thickness of the participants.

What they found

The results showed that after four weeks, the 30x 1 group didn’t show any increase in muscle strength. However, their muscle thickness, an indicator of growth in muscle size, increased by nearly 6%.

Results from the group doing six contractions once a week did not show any changes in muscle strength and muscle thickness.

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However, the 6x5 group had significant increases (more than 10%) in muscle strength. In fact, their increase in muscle thickness was similar to the 30x1 group.

Nosaka said studies continue to suggest that very manageable amounts of activity done regularly can have a real effect on people's strength.

But he underscored the need to rest in between exercise regimens. In the study, one group had two days off per week.

"Muscle adaptions occur when we are resting; if someone was able to somehow train 24 hours a day, there would actually be no improvement at all,” he said.

Muscle strength is important to our health, said the professor, as it could help prevent a decrease in muscle mass and strength with ageing.

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"A decrease in muscle mass is a cause of many chronic diseases such as cardiovascular disease, type 2 diabetes, some cancers, dementia, plus musculoskeletal problems such as osteoporosis," he said.

The study appears in the Scandinavian Journal of Medicine & Science in Sports.

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