SHAPE UP
Fitness questions answered
By Charles Stuart Platkin
Those of us who devote time to exercise seem to have endless questions relating to our pursuit of health and fitness. Since I'm lucky enough to have access to the country's top fitness pros, I've been able to track down the answers to a few frequently asked questions.
What is a MET?
A MET, or metabolic equivalent, is the energy it takes to perform a task. "One MET is considered the energy expenditure of an individual when completely at rest," says Jim Johnson, professor of exercise and sport studies at Smith College in Northampton, Mass. One MET is the amount of oxygen used by the body as you sit quietly, watching television or reading. How many METs you use depends on how much effort it takes to do the task. The harder you work, the higher the MET value. For example, biking at 6 mph takes less effort than biking at 8 or 12 mph — and the METs increase accordingly.
"Since activities require energy, each activity can be rated based on the number of METs required. For example, household activities like vacuuming and mopping require about 3.5 METs to perform," Johnson says. That is, you're using about 3.5 times more energy when you're vacuuming than when you're resting.
Does using weights (i.e., dumbbells) during cardio activity help or hurt you?
"It's unlikely that there are any additional benefits. Light dumbbells don't increase caloric expenditure or aerobic fitness by much," says Michele S. Olson, professor of exercise science at Auburn University in Alabama.
Not only that, but you're also increasing your risk of injury. "Ankle weights can change the gait and potentially cause leg, hip and lower-back injuries. And with hand weights, too much weight can strain your arm and shoulder muscles," says Gary Granata, director of the Applied Physiology Laboratory at the Ochsner Clinic Foundation in New Orleans.
Plus, even if you did use them, just holding the weights wouldn't accomplish much — you would have to swing them around, and that would make it even more probable that you would be injured, adds Olson.
And according to a study in "Research Quarterly for Exercise and Sport," exercisers who use hand-held weights may slow down, which negates any extra load that might be developed with the weights — thereby canceling any potential benefits.
Swinging your arms is a great way to increase your calorie burn without equipment, as is walking up and down hills.
What is the best strength-training exercise?
Although most exercise experts gasped at the thought of picking a single "best" exercise, I got some interesting responses. "Lunges (split squats) are best — this is a multi-joint, multi-muscle, weight-bearing and functional exercise," says Olson. "But I would add good old-fashioned push-ups and pull-ups for the upper body."
Tommy Boone, director of the Exercise Physiology Laboratories at the College of St. Scholastica in Duluth, Minn., recommends "the squat, because it involves the greatest number of muscles throughout the body and, therefore, should provide a major increase in strength at the ankles, knees, hips and lower back, along with the use of the arms to stabilize the weight upon the back of the torso."
Patrick Hagerman, a professor of exercise science at the University of Tulsa and a personal trainer, believes the best exercise, "if you had to choose only one," is the clean and jerk. This combines a squat with a military press.
Does muscle mass decrease flexibility?
First we need to define flexibility — the range of motion around the joint. According to Granata, "Increased muscle mass only limits flexibility if the muscle gets so large that it limits the range of motion — for instance, if the biceps muscle gets so large it limits the range of motion of a biceps curl."
So, putting on muscle doesn't mean losing flexibility. In fact, Olson says that other than gymnasts, Olympic weight-lifters are the most flexible athletes. "Not stretching is what actually results in not being flexible," says Olson.
When my heart races from excitement, is that the same as cardio exercise?
"Heart rate is simply used to validate the intensity of cardio work, but increasing heart rate alone, as when watching a movie or playing poker, is just that — an increased heart rate. All the other dozens of physical responses that go along with the heart rate response during exercise don't occur," says Boone. For cardiovascular training to be effective there should be muscle movement, which creates a demand for oxygen.
"Your heart then responds by pumping more blood and pumping faster. Your blood vessels and cells also respond. All of these must occur if one is to do 'cardio,' " adds Stephen C. Glass, professor of exercise science at Grand Valley State University in Allendale, Mich.
Charles Stuart Platkin is a nutrition and public health advocate. Write to info@thedietdetective.com.
