Lab Report: The Rest is Up to You

The Art and Science of Tapering

April 3, 2007

This month’s Lab Report looks at the art and science of tapering to improve your racing performance. After months of hard training in preparation for a key race, there comes a time when your focus should switch from hard work to allowing your body to recover and adapt so you are totally prepared as you approach the starting line. Let’s look at why, when and how to taper.

The challenge in designing an effective taper is to find the optimal balance between continuing to train to improve your racing fitness and resting to eliminate the physical and mental fatigue of training. It takes discipline to appropriately cut back your training so you reap the full benefits of the hard miles that are already behind you. The benefits of tapering can be looked at as simply correcting the accumulated wear-and-tear of training. More specifically, it appears that tapering leads to improvements in running economy (how much oxygen you need to run at a given pace) and muscle strength. This is not surprising because the cumulative fatigue of training reduces both of those. Tapering also allows repair of the ongoing microcellular muscle damage from training and full replenishment of the glycogen stores in your muscles and liver, as well as bolstering your immune system.

How much tapering will improve your performance depends on how hard you have been training and how you go about your taper. A review of over 50 scientific studies across a variety of sports found that tapering leads to improvements in performance of between 2 and 8 percent. In studies with runners, the benefit is generally on the order of 2 to 4 percent, which equates to about 60 to 120 seconds for a 50-minute 10K, or 3.5 to 7 minutes for a 3-hour marathon. If you are still not convinced that tapering is worthwhile, think about how many workouts you have done in preparation for your goal race. How much more improvement will you realistically gain from another tough long run versus the potential performance gains from a well-designed taper?

You should only do a full taper before a few key races each year. If you race frequently and do a complete taper for each race you will lose fitness because there will not be much time left to put in the necessary hard workouts. For most races you can do a two- to-three day mini-taper, but for the ones you truly care about you need a thorough and well-planned taper.

The ideal number of days to taper depends on both the distance you will be racing and how hard you have been training. The harder you have been training, the greater the benefits of recovery. Too short a taper will provide less than the maximal improvement in performance, while tapering for too long eventually leads to detraining. The table below provides recommendations on how long to taper for various race distances.

Race Distance Taper Duration
Marathon 3 weeks
15K to Half Marathon 11-14 days
5K-10K 7-10 days