If you want to become stronger and faster and have greater endurance, you need to exercise so intensely on one day that you damage your muscles and feel sore on the next day – and then train at a reduced intensity for as many days as it takes for your muscles to heal and the soreness to lessen. Then you take your next intense workout.
Athletes in most sports try to alternate hard workouts on one day and easier recovery workouts on the next. The faster their muscles recover, the greater their improvement from their sports training. The key to athletic training is to speed up your recovery so you can take your next intense workout. The banned performance-enhancing drugs called anabolic steroids improve athletic performance by helping athletes' muscles recover much faster from hard workouts.
How Muscles Become Stronger
Muscles are made up of thousands of fibers just as a rope is made of threads. Each fiber is made up of blocks called sarcomeres joined end to end at the Z-lines like a line of bricks. Muscles contract only at each Z-line, not along the entire length of a fiber. See the illustration.
Intense workouts cause muscle damage, which can be seen as bleeding into the muscles themselves and disruption of the Z bands that hold the muscle sarcomeres together. Significant increases in muscle strength and size come only with workouts intense enough to break down muscle Z-lines. When muscles heal they become stronger and larger.
The faster you move on your hard days, the faster you can move in competition. However, continuing intense exercise when muscles feel sore can cause injuries and an over-training syndrome that can take weeks or months for recovery.
Training to Get Better
Most athletes in endurance and strength sports exercise on their recovery days and do not plan to take days off. However, on recovery days, they work at a markedly reduced intensity to put minimal pressure on their muscles. If you develop pain anywhere that gets worse as you continue exercising, you are supposed to stop for that day. Active recoveries on easy days at low intensity make muscles tougher and more fibrous so the athlete's muscles can withstand harder intense workouts on intense days.
Almost all top runners, cyclists and weight lifters do huge volumes of work, and most of it is on their less-intense recovery days. The stresses of intense workouts are extreme; the recoveries take a long time and are done at low pressure on the muscles. Top endurance runners run more than 100 miles per week, cyclists do more than 300 miles per week and weight lifters spend hours each day in the gym.
Research data comparing active and passive recovery are scant. I am amazed at how few quality studies are available to answer this question. New training methods are developed by athletes and coaches. Then when these athletes win competitions, scientists do studies to show why the new training methods are more effective.
One study showed that runners recover faster by taking a relaxed swimming workout 10 hours after high-intensity interval running, rather than just resting (International Journal of Sports Medicine, January 2010). In another study, runners recovered strength and power faster after a marathon by resting for five days compared to those who ran slowly (Journal of Applied Physiology, December 1984).
Active recovery should be of limited intensity that does not interfere with the healing process. A one-hour recovery ride is more effective than a three-hour recovery ride after 13 days of intense bicycle training. Those who rode for three hours on their four recovery days had much lower maximal heart rates and maximal lactic acid blood levels, lower power output and slower 30-minute time trials (Scandinavian Journal of Medicine & Science in Sports, June 2009).
Recover Faster by Sleeping and Eating
Athletes in intense training recover faster by getting off their feet after they finish their hard workouts and not even walking until it is time for the next day's recovery workout. You recover faster by sleeping immediately after an intense workout or race.
Eating a high-carbohydrate meal within one hour of intense workouts hastens recovery as well (Journal of Sports Sciences, January 2004). Adding protein to that meal hastens recovery even more (Sports Science Exchange, 87:15, 2002; Physiologie Appliquée, Nutrition et Métabolisme, February 2008). Adding salt and drinking lots of fluids are also necessary for a faster recovery (Journal of Sports Sciences, January 2004).
Within one hour after your intense workouts, eat fruits, vegetables and grains (for carbohydrates) and seafood, beans or nuts (for protein), eat enough salt to replace what you have lost and drink plenty of fluids (Can J Appl Physiol, 2001;26 Suppl:S236-45). As long as the post-intense-exercise meal contains lots of protein and carbohydrates, it doesn't matter what you eat (Am J Clin Nutr, Jan 2017; Med Sci Sports Exerc, Oct 2008;40(10):1789-94). Fast foods such as french fries, hash browns and hamburgers helped athletes recover just as quickly from hard workouts as sports nutrition products such as Gatorade, PowerBars or Clif Bars (International Journal of Sport Nutrition and Exercise Metabolism, March 26, 2015).
Why You Need Protein as Well as Carbohydrates after Intense Workouts
The soreness that you feel 8 to 24 hours after an intense workout is caused by a tearing of the muscle fibers at their Z-lines. The fastest way to get muscles to heal is to have your body produce lots of insulin and also provide a supply of protein to repair the damaged tissue. We have known for a long time that insulin drives sugar into cells to be used for energy.
Now we know that it also drives protein building blocks called amino acids into the muscle cells to help them heal faster. Eating lots of protein immediately after intense exercise helps cyclists recover faster so they can ride harder for several days after an intense workout (Physiologie Appliquée, Nutrition et Métabolisme, February 2008).
Why You Should Eat Within One Hour After an Intense Workout
Intense exercise empties your muscles of their stored sugar supply called glycogen as well as damaging your muscle fibers. You recover faster from hard exercise by replenishing your stored muscle glycogen as well as healing the fibers. You have an infinite amount of fat in your body, but you have only a very meager amount of sugar stored in your muscles and liver. When your muscles run out of stored sugar, your muscles burn fat almost exclusively and you have to slow down. The more sugar you have stored in a muscle before you start to exercise, the longer and faster you can exercise that muscle.
Most cells need insulin to drive sugar and protein from the bloodstream into cells. However, when you exercise, contracting muscles can pull huge amounts of sugar out of the bloodstream without even needing insulin. This effect of pulling sugar rapidly from the bloodstream without needing insulin lasts maximally for about an hour after you finish exercising and then gradually decreases until it is gone after about 17 hours. Eating within an hour after finishing exercise helps muscles heal faster and also replenishes their stored glycogen faster than eating later. Your muscles are far more sensitive to insulin immediately after exercising, and insulin hastens muscle healing (Sports Med, 2003;33(2):117-44).
- Try to set up your exercise program so that you take a hard workout that damages your muscles so they feel sore on the next day. Then take easy workouts until the soreness goes away, and then take your next hard workout.
- Immediately after an intense workout, eat whatever source of carbohydrates and protein you like best. I eat oranges and nuts immediately after I finish an intense workout to help me recover faster for my next workout.
- When you are training properly, your muscles can feel sore every morning. If they don't feel better after a 10-minute warm-up, take the day off.
- If you feel pain in one spot that does not go away during a workout, stop that workout immediately. Otherwise you are headed for an injury.
Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana. His website is http://drmirkin.com/. Click to read Gabe's full bio.