Modelling the effect of taper on performance, maximal oxygen uptake, and the anaerobic threshold in endurance triathletes.

The purpose of this study was to determine the nature of taper required to optimize performance in Ironman triathletes. Eleven triathletes (26 +/- 4 yrs, 77.0 +/- 6.5 kg) took part in 3 months of training interspersed with two taper periods, one of 10 days (Taper 1) and another six weeks later for 13 days (Taper 2). Reducing training volume by 50% in an exponential fashion (tau < or = 5 days) in one group of triathletes during Taper 1 resulted in a 46 second (4%) improvement in their 5 km criterion run time and a 23 W (5%) increase in maximal ramp power output above the same measurement at the beginning of taper. A 30% step reduction in training volume in the second group did not result in any significant improvement in physical performance on the same measures. Training volume was reduced exponentially from the end of training in both a high volume group (tau > or = 8 days) and a low volume group (tau < or = 4 days) during Taper 2. Criterion run time improved significantly by 74 seconds (6%) and 28 seconds (2%) in the high and low volume groups respectively, while maximal ramp power increased significantly by 34 W (8%) only in the low volume taper group. Maximal oxygen uptake increased progressively from 62.9 +/- 5.8 ml.kg-1.min-1 two weeks prior to taper, to a significantly higher level 68.9 +/- 4.2 ml.kg-1.min-1 during the final week of Taper 2 (p < or = 0.5). The anaerobic threshold determined by a non-invasive method was also observed to increase from 70.9% to 74.9% of a subject's maximal oxygen uptake during Taper 2. These results demonstrate that proper placement of training volume during taper is a key factor in optimizing performance for a specific competition and a high volume of training in the immediate days preceding an event may be detrimental to physical performance.