So say Duke University's Johanna Johnson, MS, and colleagues.
"Our motto in this group, after looking at all the data, is that some exercise is always better than none, and more is better than less," Johnson tells WebMD. She's a clinical research coordinator at Duke University Medical Center.
Metabolic Syndrome Study
Johnson's team studied 334 adults with metabolic syndrome.
People with metabolic syndrome have at least three of the following risk factors:
- Large waist
- Low levels of HDL ("good") cholesterol
- High levels of triglycerides (a type of blood fat)
- Elevated blood pressure
- Elevated glucose (blood sugar) levels after fasting
When the Duke study started, participants were 40-65 years old, overweight or obese, and physically inactive. None had a history of heart disease, diabetes, or high blood pressure.
Exercise and Metabolic Syndrome
The researchers split participants into four groups:
- Low amount of moderate exercise (equivalent to walking about 12 miles per week)
- Low amount of vigorous exercise (equivalent to jogging about 12 miles per week)
- High amount of vigorous exercise (equivalent to jogging nearly 20 miles per week)
- No exercise
Participants in the exercise group didn't plunge into their workouts. They spent two to three months working up to their assigned exercise level to avoid injuries.
After that, they followed their exercise assignment for six months. They wore heart rate monitors so that the researchers could monitor their progress.
The exercisers had access to a treadmill, elliptical machine, or stationary bike at a gym. Some people in the moderate exercise group took brisk walks in their neighborhood.
Participants were free to tailor their exercise time to their schedules, as long as they met their weekly exercise goal. For most people in the moderate exercise group, that worked out to three hours a week spread over four or five weekly sessions.
Participants were asked not to diet or change their eating habits during the study.
Curbing Metabolic Syndrome
Participants who got low amounts of moderate exercise or high amounts of vigorous exercise made the biggest strides against metabolic syndrome.
The biggest improvements were seen in those who got a lot of vigorous exercise. But moderate exercise was sufficient.
"A modest amount of exercise at moderate intensity -- that's just a brisk walking pace -- and in the absence of dietary change can significantly decrease your risk of metabolic syndrome," says Johnson.
Low amounts of vigorous exercise didn't curb metabolic syndrome overall. But it did improve certain risk factors, such as waist size.
Why the difference between low amounts of vigorous exercise and low amounts of moderate exercise? The reasons aren't clear. But consistency may have mattered -- Johnson says it took more exercise sessions to meet the assigned benchmark with moderate effort than with vigorous effort.
As for the people who were assigned to stick to their sedentary lifestyles, "they got unbelievably worse in those six months," says Johnson. "So our message is that no matter what, please get up and start exercising."
That is, after you check in with your doctor. "We would always recommend that," says Johnson.
The study appears in The American Journal of Cardiology.