How Much Exercise Do We Need Each Day? Even a Few Seconds Could Make a Difference

A group of researchers recently took rapid strength training to the next level—they investigated whether it was possible to increase muscle strength with just 3 seconds of targeted exercise per day.

Participants of the study were tasked with coming into a lab and moving a lever with all their might for three seconds, five days a week for a month. The research published in the Scandinavian Journal of Medicine & Science in Sports in February found their biceps were between six and 12 percent stronger by the end.

This is an extreme example of strength training in short bursts, but it raises the question of how effective brief exercise is, say even a minute a day, and what the most efficient way to build muscle might be. Should you lift light weights often or heavy weights briefly? Newsweek spoke to experts to find out.

An important thing to consider with very brief muscle exercises is that building strength and muscle aren’t necessarily the same thing, so deciding the length of your workout depends on your goal.

“Yes, it is possible to increase strength by exercising just a minute a day,” Niels Vollaard, lecturer in health and exercise science at the University of Stirling in the U.K., told Newsweek. “Whether this is sufficient to build muscle is a different question which still needs to be answered—you can increase strength without building muscle.”

The reason for this is that strength is linked to adaptations in the muscles that can occur without the muscles actually getting bigger. The three-second study used a simple, isolated movement that people just got used to doing, according to Jonathan Little, associate professor in the School of Health and Exercise Sciences at the University of British Columbia, Canada.

“It shows that the body is capable of adapting to a novel eccentric contraction stimulus of short duration but doesn’t show that you are getting all the benefits of exercise by doing this,” Little told Newsweek. “It’s neat that muscle strength can improve with such a small dose of novel exercise but there are certainly many untapped benefits of other types of exercise that you are not going to get with this approach.”

How long should you workout a day?

Short, high-intensity exercise can have benefits. It’s all a question of disturbing homeostasis—essentially kicking your body out of resting mode and forcing it to adapt to a new situation.

“Most people will train at fairly low exercise intensities—think brisk walking, jogging, cycling, etc. This does not disturb homeostasis much, so you need to do this for a long time to get training adaptations,” said Vollaard. “But high-intensity exercise, such as the exercise used in the study, or for example brief sprints, will disturb homeostasis a lot, so you only need to do a small amount of this to get training adaptations.

“If you lack time, then short bursts are great. If you don’t like short bursts or are prone to injury, then longer, lower-intensity sessions may be better. If you want to maximize gains, then you may need to use a combination of different training sessions.”

Short exercise and long exercise each have benefits that the other doesn’t. In other words, skipping the hour-long jog for a brief sprint on a treadmill is not going to yield the same results—neither will an hour-long strength workout compared to a three-second burst of power.

“These short isolated bursts will not target your cardiovascular system at all,” said Little. “So you need to do longer bouts of exercise, or more frequent repeated short bursts to get cardiovascular adaptations.

“Also, research into strength training shows that the time that the muscle is under tension is linked to muscle growth and strength. So I doubt that you would maximize your strength and hypertrophy adaptations with short 3-second bursts of weight lifting exercise like in the study.”

How to build muscle

None of this is to say there aren’t quicker, more efficient ways of working out.

Richard Metcalfe, senior lecturer in health and exercise physiology at Swansea University in the U.K., told Newsweek that current evidence suggests the best way to build muscle and increase strength is, of course, to lift weights.

“The general recommendation is to train all the major muscle groups for 2–4 sets of 8–10 exercises for 3–12 repetitions with 2–5 min rest between sets, carried out 2–4 times per week,” he said. “That’s obviously fairly time consuming. You can make it more time-efficient by prioritizing certain exercises.

“One recent review paper suggests prioritizing dynamic movements that involve multiple muscle groups, to include at least one leg pressing exercise like a squat, one upper body pulling exercise like a pull up, and one upper body pressing exercise like a chest press. They suggest doing a minimum of four sets of 6-15 repetitions per week of each of these exercises.”

Another way that might speed things up is to lift heavy weights for less repetitions rather than lighter weights for more repetitions.

“If you lift heavier weights then you would need less repetitions to reach fatigue compared to if you were to lift lighter weights,” said Metcalfe. “So long as you lift them to the point of failure, then you should see increases in muscle size and strength over time.”

At the end of the day, it’s worth remembering that athletes have been working for years to increase strength more efficiently.

“If there was a ‘blue pill’ for increasing muscle strength, they’d have taken it some time ago,” said Kathryn Clark, a lecturer and associate program chair of movement science at the University of Michigan School of Kinesiology.