One study suggests that high intensity training bursts (Hiit) may be more effective for weight loss than longer and less intense workouts.
The research, published in the British Journal of Sports Medicine, analyzed the results of 36 previous studies.
Although all participants lost weight, those who did Hiit experienced a 28.5% higher weight loss.
The researchers warned that Hiit might not be suitable for everyone.
"Hiit could increase the risk of injury and impose higher cardiovascular stress," they said.
What does the study say?
Researchers at the Federal University of Goias, Brazil, analyzed data from 576 men and 522 women of different fitness levels.
Interval training was defined as a cardiovascular exercise that involved short, repeated efforts of intense effort, interspersed with periods of recovery. Cycling, swimming, running and boxing were included.
These training sessions were compared to longer continuous training sessions of longer duration, most of which lasted between 30 and 45 minutes. All participants exercised for at least four weeks.
Those who do interval training have lost an average of 1.58 kg (3.48 lb) compared to the 1.19 kg (2.49 lb) lost by those who were doing workout sessions. lower intensity.
Sprint interval training appears to be particularly effective for weight loss, although researchers have warned that the wide variety of training programs made it difficult to recommend a particular diet.
The NHS currently recommends at least 150 minutes of moderate aerobic activity, such as cycling or brisk walking, every week.
Dr. Niels Vollaard, a lecturer in health sciences and exercise at Stirling University, said the results were counterintuitive because most people were burning more calories over the years. 39, longer moderate exercises.
"There are two possible explanations," he said.
"First of all, Hiit can lead to greater energy expenditure after exercise – the metabolism can be increased up to a day after a Hiit session.
"Second, after a Hiit session, you may be less hungry.
"In our research, we have shown that the hormones of appetite are actually affected.
"However, it is not easy to study whether, as a result of a Hiit routine, the energy intake is reduced in the longer term, so that we still do not know not exactly why. "
Michael Mosley, who discovered Hiit seven years ago while filming the documentary The Truth about BBC Horizon Exercise, said, "In 2012, I tested three batches of high-intensity workout sessions. 20 seconds on an exercise bike, three times a week.
"My insulin sensitivity has improved by 24%.
"In the program, we have once again seen very impressive results with young and unfit people.
"The biggest problem with exercise is to compensate by eating and relaxing afterwards.
"People go on a treadmill for 30 minutes, burn about 120 calories, and then lie down and reward themselves with a muffin.
"The theory with Hiit seems to be that it suppresses your appetite and targets visceral fat in your intestines.
"It's not the calories you burn that matter, but what you will do next."