Of course, there’s a caveat: To get results from such short workouts, you have to be willing to push yourself to the limit, Gillen says. Numerous studies have shown that intense interval training protocols can get results from relatively short workouts. Gillen and his colleagues at McMaster University wanted to know how short that training could be.
The answer, from a study they did in 2016, was: one minute of intense exercise in a workout that lasts 10 minutes total (including warm-up and cool-down), three times per week.
Gillen’s team randomly assigned the participants to three groups. One pedaled a stationary bike at a moderate level of effort for 45 minutes, three times a week. A second group did three times per week 10-minute workouts that included three 20-second segments of maximal running cycling, for a total of one minute of high intensity each workout. (The rest of the time it was easy to turn). A third group served as a control and did nothing.
After 12 weeks, both exercise groups improved their insulin resistance and also increased their fitness (measured by their ability to use oxygen during exercise) by about 19 percent. Gains were similar between groups, despite the fact that the group that did short, high-intensity interval workouts had expended only about 22 percent as much exercise as the group that did longer, traditional workouts.
Similarly, a 2020 study by researchers at Erlangen University Hospital in Germany put 65 sedentary, obese volunteers through an exercise program that involved warming up on a stationary bike for two minutes, then doing five one-minute sessions a day. 80 to 95 percent of your maximum heart rate, with easy one-minute pedaling recovery periods in between. With the three-minute cool-down, the total training time was 14 minutes, and these workouts were done twice a week for 12 weeks. participants in this simple program of 28 minutes per week improved his VO2max scores (a measure of cardiovascular fitness), and also reduced blood pressure and waist circumference.
The improvements in cardiorespiratory fitness seen in these studies are a strong predictor of reduced risk of morbidity and mortality, and are especially important for people at risk of developing diabetes or other metabolic conditions, says Louise de Lannoy, an exercise physiologist at Children’s Hospital of Eastern. Ontario Research Institute.
Still, the intensity required to reap the benefits of short workouts requires some enthusiasm.
“Especially for someone who has been sedentary, going all out can be very challenging,” de Lannoy says. This level of intensity feels like the max: you’re going as hard as you possibly can. “But it can also be fun. It’s quick, with a little bit of pain, you rest and do it again,” says de Lannoy.
Another 2020 study confirmed that some people find these hard interval exercise programs enjoyable enough to continue. Exercise scientist Matthew Stork of the University of British Columbia and his colleagues brought a group of previously sedentary adults into the lab to do short, high-intensity one-minute interval exercises on a stationary bike. The participants reported that the high-intensity matches were difficult, but some of them enjoyed it enough to continue doing it after the study.
“I’ve tried these workouts myself, and it takes a lot of self-training to get to 90 percent of your max,” de Lannoy says. That said, if you do a workout with repeated hard intervals and a short rest period, they’re likely to get harder as you go, so even if your first interval is only 60 percent of your max, by third or fourth you might be closer to 90 percent, she says. If you don’t have an exercise bike, briskly climbing a few stairs is another good way to get your heart rate up quickly.
“A good rule of thumb is to build over time,” de Lannoy says. “You can start with 60 to 70 percent of your maximum heart rate and try to increase it over time and get to 90 percent.”
Short workouts can build muscle
Cardio workouts aren’t the only ones getting shortened. Studies also show that you can make big gains in strength with short sessions of resistance training.
A 2019 study published in the journal Medicine & Science in Sports & Exercise investigated the correlation between number of exercise sets performed and strength gains.
Participants in the study did a similar routine of seven strength-training exercises, three times a week. One group did five sets of the exercise in each session, another group did three sets, and the third group did just one set of exercises per workout. At the end of the eight-week program, all groups had made similar improvements in muscular strength and endurance. Doing three to five sets per workout increased the amount of time people exercised, but didn’t result in greater gains. (However, the group that did the longest workouts achieved greater increases in muscle size in the thigh muscles and elbow flexors.)
There’s often skepticism around the idea of short workouts, because they’ve been portrayed as misleading, he says. james Steele, Associate Professor of Sport and Exercise Science at Solent University in England and Senior Research Fellow at the London-based UKActive Research Institute. But he says that if your goal is to get stronger, you don’t necessarily need to spend a lot of time in the gym or do a lot of reps. Instead, the important thing is to do the exercise until you reach “failure,” the point where you can’t complete another rep. Steele was part of a research team that published evidence-based resistance training recommendations asking for a single series of eight to 12 repetitions until momentary muscular failureme.
Dutch company Fit20 runs franchise fitness studios that specialize in this “minimum effective dose” approach to workouts. He has a dataset of nearly 15,000 people who participated in his program over a seven-year period, and Steele’s team recently used it to model the progression of people’s strength over time. The team found that Fit20 members were making substantial strength gains (on the order of 30 to 50 percent gains in the first year), despite doing a minimal amount of training: a single set of four to six repetitions of six exercises, once a week.
The study shows you can make significant improvements in muscle strength with just one short workout a week, but Steele says she recommends people try twice a week so if they miss a session, they stay on track.
The minimum effective dose approach is not just for the average person. Studies carried out by Patroklos Androulakis-Korakakis, researcher at Solent University and trainer in StrongerByScience.com, a program that offers science-backed strength training, proves it works for highly trained athletes, too. he drove studies on serious powerlifters and found that they also achieve substantial strength gains while following a minimum effective dose plan.
Surprisingly, the weightlifters in the Androulakis-Korakakis studies who trained with the minimal dose approach ended up experiencing very little pain. “They had very low pain scores, one or less on a scale of one to five,” she says.
Androulakis-Korakakis says her research suggests that “Hey, you could be doing a lot less than you’re currently doing and see great results.” A minimalist approach may not give you the absolute best results, but it gives you a lot more for the money, especially when you consider the trade-offs of time and recovery, she says.
Going to shorter workouts isn’t just a way to save time. It can also help you continue to improve your fitness even when life gets in your way.
“Say exams are coming up or your work improves and you only have a couple of hours a week” to work out, says Androulakis-Korakakis. Rather than feel like his strength and muscle mass will suffer, using a low-dose approach can help you continue to improve his fitness.
“It’s hard to argue that you don’t have 10 or 15 minutes that you can find. That’s just not checking your email one more time or getting off social media,” says de Lannoy.
