Everything You Ever Wanted to Know About Exercise
We asked exercise physiologist Will Drexler to tackle your most common
questions about fitness.
Q: How accurate are the calorie-burning counters on cardio
A: Not very. They tend to overestimate calorie burn by a fair amount —
up to 30 percent, depending on the machine. Stationary bikes, treadmills, and
machines that allow you to enter your weight tend to be more accurate;
ellipticals generally exaggerate results. To determine how many calories you
can burn based on your weight for more than 220 physical activities, go to
Q: Should I eat before or after a workout?
A: After. You want to replace the carbohydrates and glycogen (stored
glucose that's used for energy) that were depleted or you'll be more
susceptible to injury and burnout. And the sooner you eat, the more likely
those nutrients will go to the place where they were expended and are needed
most. Research suggests that a snack with a carb-to-protein ratio of four to
one is the most beneficial.
Q: Why do I feel sore two days after going to the gym?
A: This is called "delayed-onset muscle soreness." Muscle
structure is broken down a little during strength-training, and soreness is a
sign that your body is rebuilding. As much as you may want to just sit on the
couch, it helps to move: Activity increases blood flow to the area, delivering
nutrients that help repair muscle.
Q: Can I tone muscle without lifting weights?
A: Any exercise that involves pushing or pulling against a resistance —
such as yoga, Pilates, push-ups, planks, and using resistance bands — is good
for muscle toning and endurance.
Q: If I want to lose weight and tone up, should I lose a few pounds first
before I start strength-training?
A: You don't have to, but many people want to see results on the scale
right away — it keeps them motivated. If that's you, start with aerobic
activity to drop pounds faster, then as you get closer to your goal body
weight, focus more on strength-training. At this point you won't see as much
change on the scale because you'll be building muscle — and muscle weighs more
than fat — but you will be improving your fitness level.
Q: Why do men lose weight faster than women?
A: Men naturally have a higher "VO2 max," which is the maximum
amount of oxygen a person can use during exercise. And the more oxygen you use,
the more calories you burn. Also, pound for pound, men have more lean muscle
mass, which burns more calories at rest than fat tissue does.
Q: Should I work out every day?
A: It's okay to do cardiovascular exercise daily, but you shouldn't
strength-train every day — your muscles need time to recover. In general, it's
good to take one day off entirely each week: Remember, exercise is stressful on
the body, plus you don't want to burn out mentally.