Competitive athletes train by “stressing and recovering,” and healthy people who do not compete in sports can gain greater benefits from their exercise programs by using this same training principle. You have to damage muscles to gain strength and enlarge muscles. You become more fit if on one day, you stress your muscles by taking a hard workout, and then letting your muscles recover by exercising at a very slow and relaxed pace with reduced force on your muscles, for as many days as it takes for your muscles to feel ready for another hard workout.
How Muscles Become Stronger
Muscles are made up of thousands of fibers, just like a rope that is made up of many strands. Each muscle fiber is made of a series of blocks called sarcomeres that are lined up end to end, and each sarcomere is attached to the next one at a “Z-line.” If you want to make your muscles stronger, you have to exercise them against resistance strong enough to damage the Z-lines, and when they heal they will be stronger. Muscle fibers do not contract equally along their length; they contract only at each Z-line. To strengthen a muscle, you have to put enough force on the muscle to damage the Z-lines, as evidenced by bleeding and swelling into the Z-lines. You can tell you have damaged the Z-lines by the feeling of muscle soreness that begins 4 to 24 hours after you have lifted weights or done any form of resistance exercise. That is the time it takes for the swelling to occur in the Z-lines. This is called Delayed Onset Muscle Soreness (DOMS).
If you exercise at a very casual pace and put very little pressure on your muscle fibers during this period of recovery, your muscles will be stronger and larger as the Z-lines heal. You should never exercise through pain. If you are trying to exercise during a recovery period and you feel pain or soreness that does not lessen or go away when you slow down or stop, you are finished exercising for that day and you can try to exercise again on the next day. Stop exercising on any day when you feel soreness that does not go away when you stop moving a muscle.
You gain a higher level of fitness by going very slowly and not putting pressure on the damaged Z-lines during your recovery days. Over the next 1-4 days or longer, the Z-lines heal and your muscles will feel fresh again. When the muscles are healed and the soreness lessens, athletes take their next intense workout. Athletes usually try to exercise every day to gain maximum strength, and most athletes take one to four days of recovery after each intense workout. If athletes exercise at low intensity during the healing phase of the Z-lines, their muscle fibers will become stronger than if they just rest.
Why Non-Competitive Exercisers Should Try to Exercise Every Day
Forty percent of North Americans die of heart attacks. One of the common causes of the arterial damage that precedes heart attacks is a high rise in blood sugar after meals. Blood sugar always rises after meals and because of faulty lifestyle habits, most North Americans have blood sugars that rise too high. Resting muscles remove no sugar from the bloodstream, but contracting muscles remove sugar rapidly from the bloodstream and can do so without even needing insulin. This effect is strongest during exercise and diminishes to no benefit after about 17 hours. The best way to use exercise to help control blood sugar is to try to do it every day.
Because a person with blocked arteries leading to the heart could suffer a heart attack during exercise, you should check with your doctor before starting a new exercise program. Whatever activity you choose, try to exercise every day. If you are just starting out, spend about six weeks at a slow pace until you are comfortable in your activity. Then you are ready to alternate more intense days with easier workouts.
Intense Days
Stress refers to intensity, not the length of time of your workout. You can gauge the severity of the stress by the amount of burning you feel in your muscles during exercise. Interval training means that you start out slowly, pick up the pace, slow down immediately when your muscles start to burn, recover by going very slowly for as long as it takes for your muscles to feel fresh, and then pick up the pace again.
On your hard days, warm up by going very slowly for five to 10 minutes. Going slowly at the start of a workout warms up muscles to help to make them more resistant to injury. If your muscles still feel tired or heavy, do not try interval training. Exercising with tired or sore muscles can cause serious injuries, which may never heal.
After you warm up, pick up the pace gradually until you feel burning or tightness in your muscles and then immediately slow down. Then go at a very slow pace until the soreness goes away, your breath returns to normal and you feel recovered. How long it takes to recover is irrelevant. You take your next faster pick up when you feel that you have recovered, not from any preset time. Then pick up the pace until you feel burning again.
If you don’t compete, you do not ever need to go at 100 percent intensity. If you are just starting to do interval workouts, you should pick up the pace only slightly and not become short of breath. Slow down and get out of the burn as soon as you feel it. As soon as the burning and fatigue go away, and you are not breathing hard, try to pick up the pace again. In early workouts, you may only be able to do one hard pickup after you have just started your workout. Do not start your next pick up until your legs feel fresh. As soon as your legs start to feel heavy, stop the workout.
Easy Days
The day after your hard workout, your muscles will probably feel sore and you should take an easy workout. If the discomfort does not go away as you continue to exercise, is worse on one side of your body, or increases as you exercise, stop exercising immediately. You are injured and continuing to exercise will delay healing. Take off the next day also if you still feel sore in one place. If you feel better as you exercise casually, continue to exercise until you feel any discomfort or heaviness. Always stop every workout when your muscles feel heavy or sore. Keep on taking easy days in which you exercise at low intensity until you feel fresh again. Do not do another hard workout until the soreness in your muscles has gone away.
My Recommendations
Every healthy person should try to exercise every day. You will gain a much higher level of fitness by “stressing and recovering,” where you exercise more intensely on one day, feel sore on the next and then go slowly until your muscles feel fresh again. Plan to go slowly on every day that your muscles feel sore, and stop a workout immediately if you feel pain in one area that does not go away when you slow down or stop. Only when your muscles feel fresh should you try to pick up the pace again.
Caution: you can suffer a heart attack or stroke when you exercise. People who have high cholesterol, blood sugar or high blood pressure, clotting or bleeding problems or any other health problems should check with their doctors before they start or increase an exercise program.
