Cyclists who participate in 40-K races and time trials often wonder if there is a simple test which can indicate how well they will perform over the 40-K distance. Such a test could provide confidence that an upcoming 40-K race will go well - and might even predict performance time in the 40-K event. Of course, determination of cycling velocity (or power output) at lactate threshold would serve both functions, telling a cyclist whether fitness had improved and also foretelling a specific time in the 40K. Some research has indicated, for example, that if power output at lactate threshold is assumed to be the power output which produces a blood-lactate concentration of 4 mmol/liter, then lactate-threshold intensity is nearly the exact intensity which will be harnessed during a 40-K race. EXPLOSIVE

Unfortunately for most cyclists, determination of lactate threshold is not so easy. For precise determination of threshold, a visit to an exercise-physiology laboratory is mandated, and the test requires time and a fair amount of money (including the cost of traveling to the lab). But - no worries: There is a much-simpler way to assess 40-K fitness. All a cyclist has to do is cover 5K as fast as possible. That's right - just 5K. Recent research indicates that for well-trained cyclists the speed sustained in a 40-K race will be 92 to 94 percent of the average velocity attained in a 5-K test. Furthermore, the power output displayed in a 40-K race can be predicted quite nicely with the following equation: Power Output(40-K Race) = .58(power output in 5-K trial) + 89.4 The power output in both cases (40K and 5K) is expressed in Watts.

Thus, a simple field test - the performance of an all-out 5-K trial - will not only provide an adequate estimation of current fitness; it will also predict rather neatly how well one will perform in a 40-K race. EXPLOSIVE