Overtraining And Cycling

The feeling of fatigue that follows a good ride or workout tells us that we are pushing our physical limits, and is a necessary part of improving our personal performance. However, in certain circumstances, fatigue may also be our only warning that we are pushing too hard and indicating a need to back off or risk a deterioration in our abilities. This is a common dilemma in a personal training program: Hard work makes us faster, but how much is too much?

Four levels of fatigue are experienced by the regular cyclist.

  1. The fatigue (or bonk) which accompanies muscle glycogen depletion develops 1 to 2 hours into a ride unless we use glucose supplements to extend our internal muscle glycogen stores.
  2. The normal post exercise fatigue which tells us we are pushing our normal training limits and will lead to improved performance the next time out.
  3. The fatigue we feel at the end of a particularly hard week of riding ( really an extension of #2) that, with recovery, will also make us faster and stronger. Exercise physiologists refer to this as “overreaching”.
  4. The debilitating and long term (often lasting weeks and months) fatigue which degrades performance and is the most common symptom of overtraining.

Your challenge is finding your own individual boundary between overreaching and overtraining.


Cyclists seem to be one of the few groups of athletes capable of reaching the over trained level of fatigue. It has been speculated that this is due to the way cycling stresses the body with a concentration of muscle activity in a single muscle group – the quadriceps. And it isn’t necessary to undertake an extensive training program to be at risk. In fact it may be those working out sporadically and with light training schedules that are most at risk. While a professional cyclist might consider a 50 mile ride as part of a light recovery week, your 20 mile ride could produce all the symptoms of overtraining.

And several studies have suggested that overtraining may be associated with other health issues above and beyond a deterioration in physical performance. One study of Harvard alumni found a lower death rate (mortality) among men expending as few as 200 Calories per week in exercise versus those leading sedentary lifestyles, but when they routinely spent over 4000 Calories on exercise per week the death rate began to rise again. And two different studies have suggested a decrease in immune system competence with intense training (cycling 300 miles per week for 6 months or 2 intensive sessions of running per day for 6 days). But before you give up exercising completely, there is plenty of evidence that a moderate cycling program will actually stimulate and improve your immune system. The key is planning your own personal training program to occasionally overreach but not overtrain.


How do you know when you are in danger of overtraining? The following are clues which could suggest that an extra day or two of rest is in order.

  1. Resting heart rate. A resting pulse rate is done on awakening in the morning and before getting out of bed. An increase of 10% or 10 beats per minute for several days in a row is accepted by most coaches as a sign to slow down.
  2. Personality/disposition. While your personal demeanor is more difficult to quantify, it may be the most sensitive and reliable indicator of overtraining. Anger, depression, and a decrease in your sense of vigor have all been reported. You won’t need a psychologist to help you with this one. Your family and significant others are usually the first to point these symptoms out to you.
  3. Performance. A short, standardized time trial every week is another helpful tool. And the changes will usually be in minutes, not seconds. If you see a deterioration, take some time off and consider switching to another aerobic activity, keeping your heart rate below 70% of maximum. (A drop in your time trial maximum heart rate of 10 beats per minute can also be a sign of overtraining.)
  4. General fatigue. Ongoing daily lethargy is a clue that it’s time to slow down.
  5. General physical complaints. Sore throat, sore muscles, and chronic diarrhea all may indicate the chronic stress of overtraining.
  6. Disruption of your normal sleep cycle. Falling asleep easily, awakening abruptly, and then feeling like you need a nap at 10 AM all can reflect the change in your normal sleep cycle associated with overtraining.


Most training programs include at least one (and sometimes two) rest days per week as well as a day or two of easy spinning. This reflects the practical experience of coaches who have had to deal with the results of pushing too hard for too long.

Over reaching is a normal part of the training cycle, but if your performance is not improving after a few days of recovery, it’s time to switch to other aerobic activities which will keep you at 70% of your max. heart rate (to maintain your level of fitness) or risk entering the zone of overtraining which may take a month or two to recover.

How long do you need to rest? Studies have indicated that recovery from overreaching (and again this means keeping your general level of aerobic activity at 70% max. heart rate, not complete inactivity) may take up to two weeks with performance improving daily. The implication of this observation is that a 1 to 2 day taper before a big event may not be enough to perform at your personal best.

As in all aspects of personal training programs there is individual variability, so it is up to you to decide where to draw your own line. But remember that rest is a key part of any training program and may be the toughest training choice you’ll have to make.

And finally, don’t forget to pay particular attention to post exercise carbohydrate replacement. Part of the fatigue of overtraining may be related to chronically inadequate muscle glycogen stores from poor post training ride dietary habits.