Dec. 13, 1999 (Atlanta) -- When weight training, the length of the interval between sets does not affect the number of calories burned, according to a study in the November issue of Medicine and Science inSports and Exercise. Experts say the findings have important implications for weight control exercise programs.
Researchers compared circuit weight training protocols with 20- and 60-second intervals between sets in seven healthy men of average height and build. Participants completed both protocols in two different sessions one week apart. Each protocol began at the leg press station and included two circuits for a total of 16 stations.
The data showed that each protocol burned about the same number of calories. Researchers say that this finding has some practical applications for resistive exercise programs. "The data suggest that weight training with moderate intensity burns about the same number of calories as weight training with high intensity," lead study investigator Ronald Haltom tells WebMD. Haltom, who is an exercise physiologist at Branch Medical Clinic in Mayport, Fla., says this means everyone can benefit from weight training regardless of fitness level.
"This is good news for people trying to lose weight and get back into shape," Haltom says. "When people begin weight training, they usually can't handle high exercise intensity. But that does not mean they don't derive a benefit. Resistive exercise is an important component of any fitness program. It's not just for bodybuilders. Weight training is for everybody." Doctors specializing in sports medicine agree.
"The American College of Sports Medicine includes resistive exercise in its guidelines for overall fitness," says Robert Dimeff, MD, who is the medical director of Cleveland Clinic Sports Health and assistant clinical professor of family medicine at Case Western Reserve University in Cleveland. "Aerobic exercise is recommended three to four times a week in combination with resistive exercise twice a week." Dimeff tells WebMD that resistive exercise has a number of benefits, including the prevention of osteoporosis.
"Weight training is not just about body sculpting. It maintains muscle mass, bone mass, and a reasonable body composition of muscle to fat. But it's got to be combined with aerobic exercise for heart and lung health as a total program," Dimeff says. "A lot of people enjoy brisk walking and research shows a speed of about three and a half miles per hour is optimal." Dimeff says that more research is needed to help guide clinical practice.
"There are lots of ways to build on our findings," says Haltom. "Studying the effects of different weights and set durations on energy expenditure would help project weight loss as a program outcome. Another study with practical application might be to compare the effects of long-term circuit weight training on metabolic responses in normal and obese populations."
- Recommendations advise that people do weight training exercises twice a week in order to maintain bone and muscle mass and to establish a reasonable ratio of muscle to fat.
- A new study shows that the length of time between sets does not affect the number of total calories burned.
- Even those who have a low fitness level can benefit from a moderate weight-training routine.