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  Last updated: 2/13/2021

Recovery and The Fatigue Syndromes
(Overtraining, Overreaching, and Chronic Fatigue)

Recovery (along with diet and structured exercise) is the third pillar of a successful training program. If you don't recover adequately, you will not get a maximal training benefit from your time on the bike. And increase the odds of sliding into one of the overtraining syndromes.

This is a nice summary of recovery by Dr. Mirkin. A few points that I would emphasize:

Fatigue with training refers to the tiredness one feels after riding. It is part of the training process in that physiologic over load with exercise, or gradually increasing work load, is the stimulus which leads to adaptation and performance improvement. Fatigue lets us know that we are pushing our physical limits. However, in certain circumstances, fatigue can be a warning that we are pushing too hard (that there is an imbalance between exercise and recovery), and indicate the need to back off or risk an actual deterioration in our performance. This is a common dilemma in a personal training program: Hard work makes us faster, but how much is too much?

Let's be a little more specific and talk about 5 types of fatigue.

  1. The bonk (fatigue resulting from muscle glycogen depletion) usually develops 1 to 2 hours into a ride. It is a particular problem if "on the bike" glucose supplements are not used to extend internal muscle glycogen stores.
  2. Post ride fatigue is a normal response to several hours of vigorous exercise and indicates we are pushing our training limits. It leads to improved performance the next time out.
  3. Overreaching is the next step up - the fatigue we feel at the end of a particularly hard week of riding. It blends with #2, and will, with recovery, make us faster and stronger. It is also a warning that we are flirting with overtraining.
  4. Overtraining is the debilitating and often long term (lasting weeks to months) fatigue which limits rather than stimulates improvement in performance.
  5. Pathological fatigue related to illness
A regular rider needs to routinely assess his or her level of post ride fatigue, trying to walk the fine line separating post exercise fatigue (necessary if one is pushing them-self) and overtraining (which can only hinder future performance). This is made even more complicated in that: can all increase the level of your fatigue with exercise or training.

And there are potential risks beyond overtraining fatigue. The data is pretty clear. You can over exercise your cardiovascular system - to the detriment of your physical health. But how much is too much? Unfortunately we, the baby boomers, are at the leading edge of the curve of a new group of ultra athletes - and only time will sort out the answer. Until then each of us will have to answer that for ourselves.

Although it may seem paradoxical, structured rest is a key component of all training programs and may be one of the toughest training choices you'll have to make. To minimize the risk of overtraining, you should include at least one and occasionally two rest days per week along with a day of easy spinning.

Over reaching is a normal part of the training cycle. It may require several extra (and unplanned) recovery days. But if you find that your performance is not improving with several extra recovery days, it's time to take a break from riding and switch to alternative aerobic activities (at 70% maximum heart rate to maintain your cardiovascular fitness). To push ahead is to risk a level of overtraining which may require a month or two off the bike to recover. Be particularly sensitive to overtraining as your signal of pushing too hard if you have made a sudden or dramatic change in:


Science supports intervals as the best path to improving your performance, but how should you split your time between your interval training and what we will call active recovery - riding at lower intensities?

This article supports the fact that maximizing training adaptation depends on the appropriate distribution of training time over the training intensity zones. Researchers compared riders based on the time spent in three different zones: Zone 1, below aerobic threshold (where you can happily spin for hours), Zone 2, which is between aerobic threshold and anaerobic threshold (or comfortably hard), and Zone 3, which is above anaerobic threshold (or where the suffering really starts).

Those who spent most of their training time in Zones 1 and 3 instead of Zone 2 enjoyed greater gains in their anaerobic power. This strategy of alternating between easy and very hard effort (avoiding the middle) is known as polarized training.

This is another well written article on training intensity balance. And for those interested, here is a link to the abstract of the original scientific paper. Although these are papers on running, the CV training benefits should be quite similar for cycling (and swimming).

So we know there are two pieces to the puzzle.

  1. Focus your training time on both ends of the intensity scale, avoiding the middle
  2. And find the right balance. Don't short change the benefits of that easy riding.
If you don't allow adequate recovery (riding at lower training intensities) you will not only fail to gain any benefit from the extra time you are putting in, but may actually sacrifice your performance.

So 20% of your training TIME at a moderate to high intensity, a perceived effort of 6 - 10 or > 77% MHR. And 80% of your training time at a PE of 4 or less.

Now that you have the numbers, the challenge will be to keep those "slow and easy rides slow and easy. My guess is you will have to work to keep that HR down.

Buried in the middle of this blog is a nice practical suggestion on how to apply the 80/20 approach to maximize improvement. Do more than this and the there is little up side but significant downside. Although this is for running, I think the same approach can be applied to biking.

To quote: "Don't calculate total miles per week in your diary; that will encourage you to pile up junk miles and prevent you from learning how to run fast. .....Set up a program in which you

Finally, this blog from Road Bike Rider reemphasizes the importance of balance.

The conclusion - and I'll quote directly -

"How many challenging workouts you can handle in a week depends on both your chronological age and your athletic maturity. The chronologically older you are the more recovery you need. The more athletic mature you are the less recovery need.

Experienced riders in their:


Fiercer competition between athletes and a wider knowledge of optimal training regimens have dramatically influenced current training methods. A single training bout per day was previously considered sufficient, whereas today's athletes regularly train twice a day or more. Consequently, the number of athletes who are overtraining and have insufficient rest is increasing.

The positive result of training in any sport is adaptation and improved performance: the super-compensation principle - which includes the breakdown process (training) followed by the recovery process (rest). Overtraining results from an imbalance between training and recovery, exercise and exercise capacity, stress and stress tolerance.

Elite sports require large numbers of training hours per week. It is assumed that the relationship between training and improved performance is an inverted U-shape. Overreaching (short term overtraining) is most likely associated with insufficient recovery in the muscle with a decline in ATP levels. Overtraining is a more complicated physiologic problem, perhaps related to failure of the hypothalamus to cope with the total amount of stress.

And to muddy the waters a bit, along with the physical stresses of excess training hours is the question as to whether a rider's nutrition is adequate to replace the Calories consumed by their physical training program. This imbalance results in a condition called RED-S (Relative Energy Deficiency in Sport).

This can be a "within-day" energy imbalance or deficiency as per this study which documented "..a significant correlation between the largest single-hour Calorie deficits and hormonal disturbances such as lower testosterone and higher cortisol." Or, as in this article a constellation of health and performance consequences that can develop over many days of riding or training due to under-eating relative to training demands.

Most regular cyclists have learned that it is not very hard to justify that extra serving at dinner after a day of riding, and see the extra pounds slowing add up. Thus a common response is to keep a close eye on the scale and the size of the servings on the plate, and guess on the low side of total Calorie replacement. But guess wrong and the risks are not only the overt physical problems such as osteoporosis or infertility, but what may be a more pervasive lack of energy that impacts daily training and riding, but may be the first step in the development of overtraining syndromes which can often take weeks and months to resolve.

To quote from the article: "It's important to emphasize that the problem here is low energy availability, not weight loss and not being too lean. .... it is possible to experience RED-S without any loss of body weight."

An ideal weight is important to staying fit and cycling at your best, so I am not advocating unbridled gluttony. But if you find you are tiring more easily than you have in the past, and are not reaching those training benchmarks, be sure to take a good look at your nutritional training program to be sure you have not underestimated your Caloric needs.

Overreaching lasts from a few days to 2 weeks and is associated with fatigue, reduction of maximum performance capacity, and a brief interval of decreased personal performance. Recovery is achieved with a reduction in training or a few extra days of rest.

Overtraining (overtraining syndrome, staleness, systemic overtraining) is the result of many weeks of exceeding the athlete's physiologic limits and can result in weeks or months of diminished performance - symptoms normally resolve in 6-12 weeks but may continue much longer or recur if athletes return to hard training too soon. It involves mood disturbances, muscle soreness/stiffness, and changes in blood chemistry values, hormone levels, and nocturnal urinary catecholamine excretion.

Stress factors such as the monotony of a training program and an acute increase in training program intensity lasting more than a few days increase the risk of development of overtraining. On the other hand, heavy training loads appear to be tolerated for extensive periods of time if athletes take a rest day every week, and alternate hard and easy days of training.

Pathological fatigue is defined as fatigue and tiredness that cannot be explained by the volume of training. These are generally medical conditions such as infection, neoplasia, disorders of the blood, cardiovascular, or endocrine systems, and psychologic/psychiatric disorders. Included in this grouping are the side effects of medications and "chronic fatigue syndrome" - an ill defined medical condition. A recent article has muddied the water even further by describing muscle changes from years of high volume exercise training that may be related to this entity. Another controversial possibility is iron deficiency without anemia - although this is much more common in endurance runners than cyclists.


For those of you interested in more on the the basic physiology of overtraining, this paper goes into more detail on the syndrome itself, and this one suggests diagnostic approaches.

The underlying pathology is speculated to be related to an autonomic nervous system imbalance and/or a problem with the endocrine system. Several findings support this thesis. During heavy endurance training or overreaching periods, the majority of studies indicate a reduced adrenal responsiveness to ACTH which is compensated by an increased pituitary ACTH release. In early overtraining syndrome, despite increased pituitary ACTH release, adrenal responsiveness continues and serum cortisol levels fall. In advanced stages of overtraining, pituitary ACTH release falls as well. In this stage, there is additional evidence of decreased intrinsic sympathetic activity and sensitivity of target organs to catecholamines - indicated by decreased catecholamine excretion during night rest, decreased beta-adrenoreceptor density, decreased beta-adrenoreceptor-mediated responses, and increased resting and exercise induced plasma norepinephrine levels.

The role of a decrease in the responsiveness of the ACTH - cortisol axis is supported by studies that show a decrease in post ride salivary cortisol levels (the level normally rises with the stress of exercise) in overtrained athletes.

There is also a psychological toll from overtraining. For the most part, the competitive athlete is a well-adjusted individual who demonstrates less depression, anxiety, and fatigue than nonathletic counterparts. The well-trained athlete, however, may also have a personality that is somewhat rigid, strongly goal oriented, and perfectionist. It is not unrealistic to expect that when confronted with diminished performance or success, such an athlete may be compelled to drive himself or herself harder to succeed. This can express itself in the form of depression and accompanying chronic fatigue.

Listed below are some of the physiologic and performance changes that have been documented with overtraining. A common thread is the inability to attain maximum energy output (aerobically as well as anaerobically) and the psychological consequences that go along with failing to do your best.

Can you exercise too much?

If you are worried about the strain on your heart or cardiovascular system, the short answer is "NO" based on this study using accelerometer data rather than self reported interviews and questionnaires (which risk being biased.) The authors found no evidence of a threshold or plateau in an inverse association between both moderate and vigorous physical activity and a lower incidence of cardiovascular disease. Their findings suggest that physical activity is not only associated with lower risk for of CVD, but the greatest benefit is seen for those who are active at the highest level.

However several other studies have suggested that too much intense training is another issue and may be associated with health issues above and beyond the risk of an immediate 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 regularly pushed their limits with over 4000 exercise Calories per week the death rate began to rise again.

And two additional 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). On the other hand there is overwhelming evidence that a moderate cycling program actually stimulates and improve the immune system.

The bottom line is that a program structured to avoid too much intense exercise provides numerous health benefits. And within those limits, you really cannot get too much physical exercise. The challenge is finding your personal limits, avoiding a transition from overreaching to overtraining. So let your body tell you when it is time for a recovery day (feelings of fatigue, musculoskeletal symptoms).


Cyclists are one of the few groups of athletes capable of reaching the over trained level associated with prolonged fatigue. It has been speculated that this is due to the way cycling stresses the body with muscle activity concentrated in a single muscle group - the quadriceps. And it isn't necessary to undertake an extensive training program to be at risk. Even those working out sporadically (and with light training schedules) are 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.


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

Personality/Disposition - While your personal demeanor is difficult to quantify, it appears to be the most sensitive and earliest indicator of overtraining. Anger, depression, and a decrease in your sense of well being and vigor have all been reported as signs of OT. 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.

Resting heart rate - A resting pulse rate is taken on awakening in the morning 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. Remember, it is the trend of your resting heart rate, taken over a period of days, that is important, not a single day's reading.

Performance - A short, standardized time trial every week is another helpful monitoring tool, and the changes will usually be in minutes, not seconds. If you see a deterioration, take some time off or consider switching to another aerobic activity (being careful to keep your exercising heart rate below 70% of maximum). A drop of 10 beats per minute in your time trial maximum heart rate has also been used as an indicator of overtraining.

General fatigue - Ongoing daily lethargy is a clue that it's time to slow down.

General physical complaints - Sore throat, sore muscles, and chronic diarrhea all may indicate the chronic stress of overtraining. An increase in minor illnesses has been reported as well.

Disruption of the normal sleep cycle - Falling asleep easily, awakening abruptly, and then feeling like you need a nap at 10 AM can reflect a change in your normal sleep cycle associated with overtraining.

Biochemical parameters - And of course there are a myriad of biochemical parameters that have been used by coaches to identify early overtraining. These include resting and exercise cortisol levels, norepinephrine levels, and lactic acid clearing after maximal exercise.

But when it comes right down to it, you are how you feel, so to speak. Your sense of well being, sense of fatigue throughout the day, and sense of perceived effort as you take that weekly ride over your regular route all appear to be more sensitive than the most sophisticated laboratory study in identifying early overtraining.


In a nutshell, overtraining is the result of "doing too much, too quickly". The body likes regular, moderate changes, not upheaval, in a training program. So don't increase your mileage or training time by more than 10% per week.

The most important aspect of preventing OT is realizing you are almost there. And a good training diary is the single most important tool you have at your immediate disposal to alert you to the risk. In addition to the usual training facts such as mileage and times, it should include a daily notation on:

For professional coaches, there are some intriguing additional tools and literature available.


Overtraining refers to prolonged fatigue and reduced performance despite increased training. Its roots include muscle damage, cytokine actions, the acute phase response, improper nutrition, mood disturbances, and diverse consequences of stress hormone responses. The clinical features are varied, non-specific, anecdotal and legion. No single test is diagnostic. The best treatment is prevention, which means

Over reaching is a normal part of the training/recovery 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 maximum heart rate (to maintain your level of fitness) or risk entering the zone of OT which may take a month or two to recover.

How long do you need to rest? If you have made a significant increase in your training schedule, and have been at it for 3 weeks or more, the chances are that you are entering that gray zone of overreaching. If so, recovery (and again this means keeping your general level of aerobic activity at 70% max. heart rate, not complete inactivity) takes at least 3 days and often up to several weeks as opposed to the normal recovery cycle of less than 3 days. The implication in that situation is that you may need more than 1 or 2 days of rest before a big event to perform at your personal best.

In addition, you can structure your training program to decrease the risk of overtraining. It should 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. Increasing variation (decreasing monotony) both in your training routine from week to week (long rides, intervals) as well within individual rides has been proven to minimize training stress and decrease the risk of OT.

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.


I ran across this personal story on and thought it might tie it all together for a few of you. To quote from that article:

"Question: I've been racing for four decades, averaging about 700 hours of training each year. But now I'm 59 and sometimes feel the motivation is just not there. I heard that a 67-year-old finished El Tour de Tucson (111 miles) in 4:51. He had significantly reduced his on-bike training to 4 days per week and lifts weights the other 3 days. Do you think I can cut back my training that way and still ride well? -- Bill S.

Coach Fred Replies: That's a great question, Bill. And because I'm 59 like you, I can provide an answer based on experience. Sometimes it's been bitter experience! I think that 700 hours of training a year may be excessive if two conditions are present:

But the real signal that you're doing too much is your level of enthusiasm. If you plan to race but then don't feel like doing it when the time comes, this conflict is a sure sign that you're overdoing it. The best indicator of long-term overtraining is loss of motivation.

In general, our ability to recover from exercise decreases as we age. But studies show that we can retain most of our aerobic power as long as our training is intense. In some cases, older cyclists who ride extremely well are doing more high-intensity workouts than they did in their 20s.That seems like a contradiction. How can we train intensely if we can't recover as well? But the answer is simple: Make more time for recovery between hard workouts. Hence the 4-days-per-week riding regimen of the Arizona roadie you mentioned.

Weight training is important, too. Past age 55 we encounter sarcopenia, a fancy name for loss of muscle volume. Resistance training helps us retain enough muscle to propel us down the road later in life.

If I were you, I'd hang up the bike for a while here in the off-season and concentrate on weight training and different aerobic activities like those mentioned above. Then when you begin riding again, limit the bike to 4 days per week. On 2 of those days, do hard work (intervals or hilly rides).Make the other 2 rides very easy. Lift 2 days per week. Take one day off to rest.

Try this schedule for 6 weeks and see what happens. I bet you'll be faster and more enthused. Keep it up and you'll ride great in road races, 40K time trials and fast centuries."

And a question I received earlier this winter:

Q. Hi, I'm a sixteen-year old cyclist who has been avidly into the sport for the past fifteen months. My interest in the sport has led me to buying books and searching the web for the best information to help me push myself just that bit faster.

In the last two or three months, my resting heart rate has been gradually getting higher and higher. I used to wake up in the morning to the sound of my heart beating around fifty times each minute, but now it seems to be up around seventy. In the time that it took for my heart rate to increase like this, I haven't noticed a large reduction in my riding capacity until now. I feel as though I have improved my fitness compared to when my heart rate was twenty beats lower, yet while on a social ride with the other members of the club today, I was going along alright until someone broke away. While the bunch chased, I couldn't maintain the high pace the other riders were producing. Cyclists who I was once much faster than had to go around me as my speed kept going lower and lower. I felt as though I just could not handle the high speed I previously thrived in.

Can you explain to me what I'm doing wrong? After witnessing what happened today, I think I am crossing from over-reaching into overtraining. I still have a huge interest in the sport and I have always kept control over my distances and intensity, always managing to have rest days after hard days. It puzzles me to see my performance drop like this - LS

A. It sure sounds as if you are working too hard at getting better. Interesting what the body can do to tell you to slow down. Since it is winter, you might consider backing way down for a couple of weeks - a little spinning. Half the miles, and a little alternative work on the cross country skis. Then when you start up again, hold it to 5 days max on the bike and a couple of them long slow distance.

Questions on content or suggestions to improve this page are appreciated.

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