Why Fatigue Is A Necessary Part Of Training And How To Manage It

Learning how to manage fatigue, and understanding the role it plays in endurance training, is critical to improving as a runner.

Training is like trying to walk a tightrope. You need to balance putting in workouts and mileage with the ability to let your body recover. Favor one aspect too heavily and you’ll either have a poor performance from lack of training or get injured and overtrain from doing too much. That’s why learning how to manage fatigue, and understanding the role it plays in endurance training, is critical to improving as a runner.

Why fatigue is necessary

The basis for all training theory is what we call the workout and recovery process. Running first breaks down your muscle fibers. The harder you run, the more muscle fibers you damage. Your body then works to rebuild these damaged muscle fibers, and if the recovery process goes well, these muscle fibers are repaired stronger than before. That’s how you become faster and stronger through training.

But, as you may realize, it’s nearly impossible to recover fully from a workout in 24 hours. It might be possible following a very easy day of running, but any type of speed, tempo or long run is going to require anywhere from 2 to 14 days to fully absorb and recover.

That means, unless you want only to run two or three times per week, training while fatigued is necessary —especially since slow, easy mileage is the foundation for running performance and the best way to build aerobic endurance. The trick is finding that balance between running enough miles to build your aerobic capacity without overdoing the fatigue. Herein lies the “art” of training.

However, there is also a way that we can utilize this fatigue to make your training more effective.

RELATED: Do This Sprint Workout To Build Up Leg Speed

How to utilize fatigue to run faster

In training vernacular, coaches use a term called “accumulated fatigue”. This theory posits that fatigue from one workout accumulates and transfers to the next run. You’re always starting a workout or a long run a little tired from your previous training.

This is important for longer distance races like the marathon because it’s nearly impossible to run the full distance of the race in daily training. Furthermore, if you were to start every workout fully recovered and fresh, it would be difficult to simulate how your body feels late into a race.

As such, we can strategically implement the theory of accumulated fatigue to better target the specific demands of your race.

For example, during marathon training, one of my favorite methods for introducing accumulated fatigue is to buttress the long run against a shorter, but steady paced run the day before. For example, you would run six miles at marathon pace on the Saturday before your Sunday long run. Because of the harder running on Saturday, you start Sunday’s long run not at zero miles, but rather at six or eight miles, since that is the level of fatigue and glycogen depletion your body is carrying over from the previous run.

How to find the right balance

Training would be much easier—and runners much happier—if you could just train hard and be fatigued all the time. But, you can’t simply continue to accumulate fatigue and constantly run these types of workouts (although some runners certainly do try). There needs to be a balance.

First, try to keep the specific accumulated fatigue workouts to once every two weeks. Only schedule them during the race-specific portion of your training schedule. This ensures that you don’t overdo it and that you will not get burnt out long-term.

Be sure to keep your easy runs slow. One of the most common mistakes runners make is running their easy day mileage too fast. This hinders your ability to recover and doesn’t provide any additional aerobic benefit. Research has shown that the most optimal aerobic pace for an easy run is about 65 percent of 5K pace. For a 20-minute 5K runner (6:25 pace for 5K – 7:20 pace marathoner), this would mean about 8:40 per mile on easy days.

Finally, don’t be afraid to take a down or rest week every five to six weeks. In these weeks, reduce mileage by 65 to 75 percent and reduce the intensity of workouts. Down weeks help you fully recover from and absorb previous weeks and months of training so that fatigue doesn’t build-up too much.

Hopefully, this lesson on fatigue and how you manage it will help you train more intelligently for your upcoming races.

RELATED: How To Start Running Again After A Short Time Off

Originally seen on