Health Claims

After water workouts—whether intense bursts or steady-paced—the oxygen levels in healthy young women go back to normal within 15 minutes, meaning their bodies recover quickly and don’t burn extra oxygen for long afterward.

For healthy young women, doing short, super-intense water workouts doesn’t burn more calories after exercise than steady, moderate water workouts — both burn about the same extra amount afterward.

For young, healthy women doing water workouts, swimming at a steady, moderately hard pace for 30 minutes burns more total calories than doing short, super-intense bursts with rest in between—even though the bursts burn more per minute.

For college guys who are overweight, doing quick, intense Tabata workouts burns more calories after the workout than easier, longer ones — and it works just as well as other intense workouts when it comes to keeping metabolism high afterward.

For overweight or obese male college guys, doing 4 minutes of intense Tabata workouts burns more fat after the workout than longer, less intense exercises — and that fat-burning boost lasts longer too.

For overweight or obese male college students, doing Tabata workouts means their bodies burn more sugar for energy during and after exercise compared to other types of workouts like regular HIIT or steady jogging.

For overweight or obese male college guys, the Tabata workout burns more calories per minute — even when you count rest time — than other types of cardio, according to this claim.

For overweight or obese male college students, the Tabata workout burns fat faster during and after exercise than other common workouts, even though it's shorter.

Taking a supplement called epicatechin while doing four weeks of cycling doesn’t seem to change a muscle protein that controls growth — at least in regular gym-goers.

Taking 200 mg of a compound called (–)-epicatechin every day for a month doesn’t help boost short-burst cycling performance more than a placebo in regular exercisers.

Doing four weeks of regular cycling boosts your body's natural antioxidants, whether or not you take a 200 mg daily supplement called (–)-epicatechin. The exercise, not the pill, is what makes the difference.

If you're a regular exerciser doing cycling, taking 200 mg of a compound called epicatechin every day might stop your muscles from building up a key energy-related protein that usually goes up with training—while people on a fake pill actually see an increase.

If you're a regular exerciser doing cycling, taking a supplement called (–)-epicatechin every day might actually stop you from getting fitter, while people taking a fake pill (placebo) do get fitter over 4 weeks.

Doing moderate, steady exercise doesn’t seem to change key muscle genes linked to making new mitochondria — the cell’s power plants — so the benefits might come from making existing ones bigger or merging them, not creating new ones.

Doing steady, moderate exercise regularly might help your muscle cells' energy factories work better by boosting a protein that helps them merge and stay healthy.

Doing steady, moderate exercise regularly can noticeably boost your fitness level — especially if you're out of shape or older — with real improvements in how well your body uses oxygen after just a few weeks.

Doing steady, moderate exercise might give a small boost to a muscle enzyme that helps with energy, but the evidence isn’t strong enough to say for sure.

Doing moderate, steady exercise like brisk walking or cycling for several weeks might boost the energy powerhouses in your leg muscles, which could help your body burn fuel better and improve overall health.

Sitting in heat for six weeks can be as good as regular cardio for improving fitness and blood sugar control in young, inactive guys—even though the heat doesn’t change muscle metabolism. The benefits might come from better blood flow in small vessels instead.

Sitting in heat for six weeks doesn’t give young inactive guys the same muscle benefits as regular cardio exercise — things like energy production and fat storage in muscles don’t improve like they do with actual workouts.

Sitting in a hot room for about 45 minutes three times a week might improve blood vessel health in inactive young guys just as much as regular cycling — even if they don’t actually exercise.

People who start out less fit tend to see bigger improvements in their stamina and muscle health when they begin exercising, no matter their age or gender — the lower your starting fitness, the more you gain.

When people who aren't very fit start exercising, their muscles grow new blood vessels quickly in the first month, but after that, even if they keep working out, they don’t get many more new blood vessels.

If you're just starting to get fit, different types of workouts like steady jogging, intense intervals, and all-out sprints all help grow similar numbers of tiny blood vessels per muscle fiber. But jogging-style workouts boost blood vessel density more because they don’t make your muscles grow as much, so the vessels aren’t stretched thinner.