AP Photo/Jeff Chiu
To perform your best in an Ironman triathlon, you must do two things:
1. Achieve a high level of race-specific fitness
2. Start the race in a rested and ready state
It is the job of your training program to develop a high level of race-specific fitness. It’s the job of your pre-race taper to ensure that you show up at the start line rested and ready.
A taper is a short period of reduced training immediately preceding a race that enables the body to fully compensate for recent hard training. This is done by stocking the muscles with fuel and repairing muscle damage. Tapering maximizes race performance by eliminating the pre-fatigue that limits performance in everyday workouts. A well-executed taper also boosts race performance by essentially priming the body for maximal effort--in much the same way a good warm-up does. This is why the most effective taper involves reduced but continued training instead of complete rest.
Studies have compared the effects of different tapering methods on performance. Tapering variables include the duration of the taper, the degree of initial training reduction, the rate of training reduction thereafter, and the amount of high-intensity training that is performed during the tapering period. It's impossible to draw uniform, universally applicable conclusions from the total body of such studies, but there are some consistent findings that provide useful, general guidelines for tapering.
The best results seem to follow when the taper is at least one week long, the volume reduction is at least 50 percent compared to the previous week, and the tapering period includes a fair amount of race-pace efforts (instead of being entirely low-intensity). For example, in a study from East Carolina University, a group of runners lopped an average of 29 seconds off their 5K race times after completing an eight-day taper in which training volume was reduced by 70 percent compared to the previous week and a small number of race-pace intervals were run each day.
Common Tapering Mistakes
While a taper need not be perfect to be effective, there are two common tapering errors that often do have a measurable negative impact on race performance. The first is trying to get away with a one- or two-day taper. A day or two of light training does not provide enough opportunity for your body to fully absorb and adapt to the preceding hard training, assuming you have maintained a relatively high training workload (more than six hours per week) until this time. The more hours you train each week and the longer your race is, the longer your taper should be. Most Ironman triathletes should begin reducing their training two weeks before race day.
A second common tapering mistake is doing too little high-intensity training during the tapering period. Research has consistently shown that a taper featuring a fair amount of high-intensity training is more effective than one featuring only easy efforts. While the overall volume of high-intensity swimming, cycling and running you do during the tapering period should be reduced compared to the peak training period, your easy training should be reduced to a much greater degree.
A low-intensity taper will probably serve you better than no taper. However, inadequate high-intensity training in the tapering period is a common cause of the seemingly inexplicable "flat race"--those days when you "just don’t have it" even though you’re extremely fit. High-intensity training keeps your nervous system primed for hard work in the final days before racing. When you fail to do high-intensity training at this critical time, the stress of racing can come as a shock to the nervous system, reducing muscle output.