How to Taper to Boost Performance

I attended a high school that was known for its swimmers. They were the best in the country, and some of them competed in the Olympics. Before championship meets, you could overhear amusing discussions in the hallways about "shaving down" and "tapering" in an attempt to swim faster. As a member of the cross country and track teams, I was also interested in getting faster.  So I couldn't help but eavesdrop. "What were these odd-sounding things," I wondered. "Could they work for me, too? Do swimmers have a secret?"

The idea of progressively reducing, or tapering, the training load has been a long tradition among swimmers, the most often-studied athletes in regard to tapering. While it's not necessary as a runner to shave all of your body hair to run faster, you may benefit from tapering your training.  

Since most runners are a driven bunch, it seems unnatural to cut your weekly running volume to a fraction of your current training. Competitive runners think they should always do more. But that's one of the most interesting things about fitness—adaptations to training occur during recovery periods, not during the training itself. When you taper, you provide your body the opportunity to recover, adapt and overcompensate for the training you've done so you're prepared to run your best race.

Performance Effects of Tapering

Most research on runners, swimmers and cyclists has shown that improved performance (from 0.5 to 6 percent) is more likely to occur after a period of tapering. Studies on runners have been limited to 800-meter performance, time to fatigue on a treadmill at 1500-meter race pace, 5K performance and treadmill half-marathon performance. As with any type of training, these studies have shown a large individual response to tapering. One study using 800 meters and another using a treadmill half marathon as the performance measures found that while tapering had a positive effect on selected physiological parameters, it did not have an effect on performance.  

Physiological Effects of Tapering

Some of the more prominent physiological changes that occur during the taper happen in the blood, such as increases in red blood cell volume, total blood volume and reticulocytes (immature red blood cells), and improvements in the health of red blood cells. These hematological changes reflect a positive balance between hemolyis (the degradation of red blood cells) and erythropoiesis (the production of red blood cells), leading to a greater oxygen-carrying capability and, often, an improved performance.  
Tapering also increases 
  • muscle glycogen content (fuel for when you race) 
  • aerobic enzyme activity (allows for greater aerobic metabolism) 
  • muscular strength and power 
  • maximum oxygen consumption (VO2 max) 

There is also a decreased level of the enzyme creatine kinase, an indirect indicator of muscle damage, in the blood, which reflects an increased recovery.

More: Recovery Tips for Runners

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About the Author

Jason R. Karp, Ph.D.

Dr. Jason Karp is one of the foremost running experts in America, 2011 IDEA Personal Trainer of the Year, 2014 recipient of the President's Council on Fitness, Sports & Nutrition Community Leadership award, and creator of the Run-Fit Specialist certification. He holds a Ph.D. in exercise physiology. A prolific writer, he has more than 200 articles published in international running, coaching, and fitness magazines, is the author of five books, including Running for Women, Running a Marathon For Dummies, 101 Developmental Concepts & Workouts for Cross Country Runners, and 101 Winning Racing Strategies for Runners, and is a frequent speaker at international fitness and coaching conferences. Follow Jason on Twitter @drjasonkarp and Facebook at DrJasonKarpRunFit.

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