I was recently asked about "crash" training, which I wrote about in my Training Bibles. I've written about this before, but not in much detail. So perhaps it's time to go back to what I've said in my books on this topic.
In the world of sports, it is quite common that athletes and coaches discover something that obviously works followed by science attempting to explain why. For example, such breakthroughs as aero’ handlebars, the Fosbury Flop high jump method, clap skates in ice skating, and the skate technique in cross country skiing all came from athletes and coaches—not scientists. It wasn’t until sometime after each of these discoveries that science quantified the benefits and explained why they work.
So it is with producing peak performances in endurance sports.
For decades road cyclists have used multi-day stage races to springboard performance to higher levels. The lore of cycling is filled with stories of dramatic gains in fitness following several days of back-to-back racing and an extended active recovery period.
Scientists, athletes, and coaches have always known that in order to produce positive changes in fitness, high levels of stress must be applied followed by rest. The body adapts to the increased stress in many ways resulting in improved performance. Athletes and coaches call this process “hard training;” scientists call it “overcompensation.”
Several studies have shown that when several stressful workouts are spaced closely for several days with inadequate rest and followed by a long rejuvenation period that overcompensation is enhanced—as in a stage race. This is known as “supercompensation.” This risky flirtation with overtraining is also sometimes called "crashing"—a descriptive, if somewhat ominous name.
Two studies in the early 1990s explored supercompensation. In 1992 a group of seven Dutch cyclists increased their training volume from a normal 12.5 hours per week to 17.5 hours for each of two weeks. They also boosted their intense training from 24 to 63 percent of total training time during that period. At the end of two weeks there was a significant decrease in all aspects of their fitness—they were on the edge of overtraining. But after two weeks of recovery, the riders experienced a 6-percent increase in power, their time trials improved by an average of 4 percent, and they produced less acidity at top speed compared with pre-crash levels. Not bad for two weeks of hard training.
Another study in Dallas put runners through a two-week crash cycle with similar results, but there was also an increase in aerobic capacities. Again, it took two weeks of active recovery following the crash cycle to realize the gains. Other research on this topic suggests an increase in blood volume, greater levels of hormones that produce muscle growth, and an improved ability to metabolize fat resulting from a long-term crash-recovery period.
These and other studies reveal three guidelines about crashing.
Guideline #1: It takes about three weeks to produce overtraining in young, well-trained athletes, so crash cycles must not go that long, and should probably be far shorter—especially for older athletes. In a study of young, elite rowers preparing for the World Championship, three hours of daily training for three weeks were necessary to produce overtraining. If you’ve never trained this way before then it’s best to start by doing no more than three or four consecutive days of crash training to see how your body responds.
Guideline #2: Large volume increases are not as effective at producing supercompensation as dramatic increases in intensity. Researchers doubled the weekly mileage of a group of well-trained runners for three weeks, and at another time, doubled the number of miles that they ran at high intensity for three weeks. Following the high-volume phase, endurance and running performance plateaued, but it improved following the increased-intensity period.
Guideline #3: It takes a half to a full day of active recovery for every day spent crashing. Short crash cycles of, for example, four to seven days are best followed by an equal number of easy-workout, recovery days. Longer crash cycles, in the neighborhood of 14 to 21 days, which are quite risky and probably best avoided by nearly all athletes, may be matched with fewer recovery days, about one-half day for every day of crashing.
Be careful with crash training. The risk of overtraining rises dramatically during such a build-up. That could ruin your season and perhaps even your career. It’s important that your fitness base (especially aerobic endurance and muscular endurance) is well established before starting such a difficult training period. If signs of overtraining appear—such as a greatly changed resting heart rate, muscle or joint soreness, feelings of depression, inability to sustain fast efforts or extreme fatigue—cut back on the workload immediately and take a rest day. It is probably best not to attempt a crash cycle more frequently than once for each racing peak in the season. And that is probably best done in the Build period leaving at least 3 weeks remaining until the race.
Costill DL, et al. 1988. Effects of repeated days of intensified training on muscle glycogen and swimming performance. Medicine and Science in Sports and Exercise 20: 249-254.
Jeukendrup AE, et al. 1992. Physiological changes in male competitive cyclists after two weeks of intensified training. International Journal of Sports Medicine 13 (7): 534-541.
Kirwan JP, et al. 1988. Physiological responses to successive days of intense training in competitive swimmers. Medicine and Science in Sports and Exercise 20: 255-259.
Lehmann MJ, et al. 1992. Training-overtraining: Influence of a defined increase in training volume vs. training intensity on performance, catecholomines and some metabolic parameters in experienced middle- and long-distance runners. European Journal of Applied Physiology 64 (2): 169-177.
Lehmann MJ, et al. 1997. Training and overtraining: An overview and experimental results in endurance sports. Journal of Sports Medicine and Physical Fitness 37 (1): 7-17.
Steinacker JM, et al. 1998. Training in rowers before world championships. Medicine and Science in Sports and Exercise 30 (7): 1158-1163.