When researchers at France's National Institute of Sport asked a group of triathletes to ramp up their training by 40 percent and maintain that volume for three weeks, the results were predictable-at first. By the end of week one, the athletes showed signs of overtraining, like excessive fatigue and an inability to get their heart rate up to its max, and they began to run more and more slowly. But after the three weeks and a week of easy training to recover, their performance rebounded. They ended up running faster than the athletes in the control group, who had trained at their usual levels.
Pushing yourself beyond your limits for a few weeks-a tactic coaches call "functional overreaching"-can force your body to adapt and build fitness more quickly than the usual slow-and-steady approach. Be warned: Training through heavy fatigue is a high-risk approach that can progress to full-blown overtraining if you don't pull back in time, and it's not easy to get the timing just right. But if you've been stuck at a performance plateau for a few seasons despite consistent training, the gamble may be worthwhile.
Ramp Up The Volume
Increasing either volume or pace can push you into the overreaching zone, but volume is the safer bet. Speeding up makes it hard to control exactly how much extra fatigue you get, and you risk turning aerobic workouts into anaerobic ones. For the first week, increase your mileage by 15 percent by lengthening easy, long, and tempo runs; spread out the extra miles over a few days, and don't change your high-intensity workouts. If you're struggling to recover after the first week, simply maintain this mileage increase. If you still feel "normal" increase volume by another 10 percent, adding one or two double runs if necessary. In either case, as soon as you start feeling unusually fatigued, you know you've entered the overreaching zone. Hold the higher volume for two weeks from that point, and then back off.
Monitor The Signs
A concrete way to detect this unusual fatigue is to repeat a standard workout, like the six-mile tempo that British Olympic 1500-meter runner Andy Baddeley does every Thursday. He always runs at the same heart rate (just below his lactate threshold), then he times how long it takes for his pulse to drop below 125 beats per minute after he stops. Sudden increases in the tempo or recovery time signal that the body is struggling to recover, which means you should start the two-week maintenance phase of overreach training. To try this approach, start doing a weekly three- to five-mile tempo run at least four weeks before you ramp up mileage, keeping your heart rate between 80 and 85 percent of max after the first mile, and repeat every week until the overreach phase ends. You can also take your resting heart rate first thing every morning: If the seven-day average drops by more than three beats, that suggests you're overreaching.
The biggest mistake you can make after an overreaching block is to settle back into your regular training, letting the accumulated fatigue linger. Instead, immediately drop your mileage down to about 60 percent of its pre-overreach levels for one week, and dial back the intensity of your hard workouts. Make an extra effort to get plenty of sleep, and book a massage to address any minor aches. If you don't feel refreshed and raring to get back to full training after this recovery week, that's a serious warning sign that you may have overdone it. In that case, bring the mileage down to 40 percent of normal for another week and stick to easy runs.