Listen to Your Body

by Gabe Mirkin, M.D.

The best way to achieve a high level of fitness without injuring yourself is to listen to your body. Don’t depend on heart rate monitors, fitness trackers or other gadgets. The most sophisticated fitness tracker and injury-avoider is your brain. Training to achieve a high level of fitness and to prevent diseases usually involves intense exercise, and most exercise injuries are caused by continuing to exercise intensely when your body tells you to slow down, stop exercising, or take the day off.

You Don’t Need Electronic Devices to Track Exercise

You can buy clever gadgets to monitor your heart rate, blood lactic acid, carbon dioxide, sugar and oxygen levels, speed or cadence, number of steps or breaths or arm motions that you take, stride length, and so forth.

However, these devices cannot tell you whether you are exercising intensely enough to gain your maximum improvement in ability to take in and use oxygen or to damage your muscles enough for maximum strength gain. Only your brain can tell you:

• whether you are at your maximum,
• when you need to slow down because you are exhausted, or
• if you need to stop because you are about to injure yourself.

Fitness gadgets can help to motivate you and can be fun to use, but do not count on them to tell you how intensely you should exercise or when you are at the edge of an injury.

Your Brain Talks to You

Your brain can tell you when you are tired, short of breath and your muscles hurt. All you have to do is to ask yourself, “How do I feel?” Researchers can measure signs of fatigue such as lactate levels, VO2max, heart rate, heart-rate variability, rapid morning heart rate, recovery heart rate, hormone levels, red cell counts, your immune system’s activity (white blood cells, interleukins, inflammation), muscle damage, blood pressure, and much more. But in the real world for athletes and regular exercisers, all you need to do is listen to your body.

For example, the test called VO2 max measures the maximum amount of oxygen you can take in and use over time, which is the major limiting factor to how fast you can move. However, you do not need to monitor VO2 max with a machine; you can increase VO2 max just by exercising intensely enough to become short of breath.

Stress and Recover

Almost all competitive athletes use the training principal of “stress and recover”:
• On one day they take an intense workout to damage their muscles.
• On the next day they feel sore and go less intensely to allow their muscles to heal.
• Then when their muscles feel fresh again, they take their next intense workout.

Running causes tremendous muscle damage, so runners usually run very fast only two or three times a week, run long once a week and have three to five slower recovery days, even if they are working out twice a day. Competitive swimmers are different. The water seems to protect their muscles so they usually try to take one hard and one easy workout every day. Pedaling causes less muscle damage than running, so bicycle racers do some fast riding on most days, and have to learn when to slow down.

How Does This 84-Year-Old Bicycle Rider Train?

I spent my entire competitive running career (from 1954 to 1989) injured because I competed with my training log in the mistaken belief that the runner who does the most miles is the best. Of course, that is ridiculous. It took me 35 years to learn when to take days off. Today, I am no longer a runner. Bicycle riding is done in a smooth rotary motion with no road shock, so cyclists can stress their legs almost every day.

Diana and I ride very fast in a tandem bicycle group of couples in their 40s to 80s. We usually ride about 30 miles on Tuesday, Thursday and Saturday. After these hard rides, my legs are always sore when I get up the next day. I take a very slow 10-minute warm up. If my legs still feel tired or stiff or I have localized pain after the warm up, I take the day off. If my legs feel fresh after the warm up, I take an easy ride for an hour or so.

If I feel really fresh, I do a series of standing 50-pedal-stroke intervals fast enough to make me short of breath each time, followed by a slow recovery for as long it takes to get my breath back and for my muscles to feel fresh again. I do not time recoveries, since starting an interval before full recovery would slow down my next interval. As soon as my legs start to feel heavy, I stop the interval workout and start my short, slow cool down.

I am riding about 125 miles a week (30-mile fast group ride three times a week plus about 12 miles of warm up and intervals three times a week). My 30-mile rides are fast, but not flat out, and depend on how I feel. Of course I go slower on some days. I do 21 to 24 fifty-pedal-stroke intervals on my average interval workout, which takes about 40 minutes. I always stop my interval workout when my legs start to feel heavy. I am usually forced to take off or go very slow at least one or two days a week.

Rules to Prevent Wear-and-Tear Injuries

• When you are training or exercising properly, your muscles are likely to feel sore almost every morning when you get up. If you warm up for a workout and your muscles don’t feel fresh after 10 minutes, take the day off or go very slow, no matter what kind of workout you have planned for that day.
• Wear-and-tear injuries don’t just happen; they give you plenty of warning. If you feel soreness or pain in one area that worsens as you continue to exercise, or doesn’t go away when you slow down, stop your workout immediately. You are headed for an injury.
• Wear-and-tear injuries are usually not symmetrical. One side of your body will feel far more uncomfortable than the other. Stop your workout if you feel localized tenderness in one muscle group and you do not feel the same discomfort in the same muscle group on the other side of your body.
• Stop your intense workouts immediately when your legs start to feel heavy or hurt.
• You recover faster from a workout by eating food and drinking fluids as soon as you finish, and getting off your feet as much as possible. You recover faster by lying down instead of sitting, and sitting instead of standing. Eat lots of food soon after you finish an intense workout and then take a nap.

Caution: People who have narrowed arteries leading to the heart can suffer heart attacks when they exercise intensely. All vigorous exercisers must learn when to back off of training because not allowing enough time to recover from hard exercise can damage your heart muscle as well as your skeletal muscles. Check with your doctor before beginning an exercise program or making a sudden change in the intensity of your existing program.