The pervading paradigm amongst serious athletes, recreational athletes and the general population of fitness enthusiasts appears to be that the more they train, the better they will perform. However, performance and results depends not only on a high level of commitment; but it relies on a carefully designed program where training is complemented by appropriate recovery.
The US Olympic Committee defines overtraining as "the syndrome that results when an excessive, usually physical, overload on an athlete occurs without adequate rest, resulting in a decrease in performance and the inability to train." An alternative but similar definition is that overtraining refers to "the point where the athlete starts to experience physiological maladaptations and chronic performance decrements" (Fry et al, 1997).
The maxims "more is better" and "no pain, no gain" can eventually lead to decrements in performance through overtraining syndrome (OTS). It appears that OTS is a very common phenomenon. It has been reported to be present in:
- More than 60 percent of elite distance runners at least once in their career
- 21 percent of the Australian swimming team after six months of training for a national competition
- More than 50 percent of players in a soccer team in a competitive season
- 28 percent of athletes competing in the 1996 Summer Olympics
- 10 percent of athletes in the 1998 Winter Olympics
OTS is not just a problem with elite adult athletes. It is now also common in young athletes, where it tends to manifest in the form of increased injury rates. Due to the large amount of sports specific training being undertaken, overuse injuries are now common among young athletes. DiFiorni conducted a major review of overuse injuries in children and adolescents and found that 49.5 percent of 394 sports injuries were classified as overuse, and the type of sport practiced played a major role. For instance, 60 percent of swimmers’ injuries were due to overuse, compared to 15 percent of soccer players’ injuries.
The Root of the Problem
Why is overtraining so prevalent when our knowledge of sports science is increasing all the time? It appears that both athletes and coaches are to blame. Training loads (mainly the responsibility of coaches) are increasing, by some estimates, at a rate of 10 to 20 percent every five years. When Mark Spitz won seven gold medals at the 1972 Olympics, he swam an average of 9000 metres per day in his training routine. This was surpassed by average university/college swimmers by 1990 and almost quadrupled (35000 metres) by Olympic swimmers in 1995. However, coaches should not shoulder all the responsibility. It appears that an athlete’s drive for continuous performance improvements is at least partly to blame, as Armstrong and VanHeest point out in their excellent review, "Athlete frustration leads to increased practice time each day and increased training intensity, which results in less regeneration, increased fatigue and worsening of performance." It would appear that both athletes and coaches have not caught on to what sports science tells us: sometimes less is more.
The price to pay for overtraining can be a high one. While most athletes who become overtrained miss only a few days of training (if action is taken early), the symptoms can and do last much longer. This is particularly true for those who ignore the early warning signs.
Principles of Training
In order to explore OTS properly, we must view it in the light of the key principles of training: the FITTE principles, progressive overload and periodization.
Perhaps the single most important principle is that of progressive overload. This is related to the General Adaptation Syndrome, made famous by the Physiologist Dr Hans Seyle. The basic premise is that the body needs a stimulus (in this case, physical stress) in order to adapt. If the stimulus (training load/volume) remains constant, the body will only adapt to that level of stimulation. However, this progressive overload must be carefully managed if the body is to avoid encountering OTS. This is where FITTE principles and periodization come into play.
When designing any program, there are several components to be considered. These components are known as FITTE principles. Applying the FITTE principles ensures that a program is specific to the individual and is successful over the long term. FITTE stands for:
F – Frequency of training
I – Intensity of a training session
T – Type of training
T – Time of the session
E – Enjoyment
It should be remembered that the most significant gains in performance come from long term consistency. Therefore, for longevity of training, coaches and fitness professional should consider the last two components of the FITTE model: type of training (gains are specific to the type of exercise) and enjoyment, as these tend to have the biggest influence on an individual's motivation.
The other components, frequency, intensity and time of sessions, are best applied by adhering to the principles of periodization (i.e., different phases of high training stress and planned periods of recovery). A scientific periodized program can be quite complicated, depending on the type of sport/training, and a complete overview is beyond the scope of this article. In general terms, however, it is important to remember that intensity and volume are inversely related. While it may be tempting to increase both intensity and volume, intensity and volume should never be increased simultaneously. A proper periodized program also needs to take into account an off season, a general conditioning period, a specific conditioning period and a period of skills training (if indeed, the sport requires a high level of skill). Finally, the real art comes in during the in season. It is often a very delicate balancing act when maintaining optimum conditioning during intense competition, and different athletes often respond differently to training and competition demands (other factors will be discussed later).
Types of Overtraining
The picture of OTS is further complicated by the existence of two different types: one that primarily involves the sympathetic nervous system and the other involving the parasympathetic nervous system (different branches of the autonomic nervous system). It appears that the different types of OTS involve interactions of different neurotransmitter systems (chemical messengers within the brain and nervous system), such as serotonin and noradrenalin (called norepinephrine in the US) as well as hormones such as testosterone, DHEA (both anabolic hormones that induce muscle growth and repair) and cortisol (a catabolic hormone that induces breakdown of body tissues, particularly proteins).
Parasympathetic symptoms of overtraining include low resting heart rates, hypoglycemia during exercise, rapid recovery of heart rate post-exercise, decreased maximal plasma lactate during exercise and decreased catecholamine levels. Other symptoms may include inhibition, staleness, performance incompetence and depression.
Parasympathetic overtraining is the more common type and is typically found in aerobic athletes such as distance runners, cyclists and swimmers. Two hormones that are often impacted by high volume training are testosterone and cortisol, and as the training volume increases, the ratio of these two hormones is altered. Although these symptoms are well known, they are often overlooked, so it is imperative that fitness professionals keep a sharp eye on the client’s behavior and mood.
According to Lehmann et al, sympathetic symptoms of overtraining are more common in younger individuals who train for speed and/or power. It also appears that these symptoms may develop before the parasympathetic overtraining syndrome, and some of the features are restlessness, excitation and performance incompetence. Additional symptoms are increased heart rate, blood pressure, metabolic rate and respiration, which all appear to be due to increased levels of catecholamines.
|Low resting heart-rate
||High resting heart-rate
|Rapid post-exercise heart-rate recovery
||Decreased post-exercise heart-rate recovery
|Decreased catecholamine levels
||Increased catecholamine levels
|Hypoglycaemia (low blood sugar)during exercise
|Decreased blood lactate during exercise
||Increased blood pressure
||Increased metabolic rate
||Increased respiratory rate
||Loss of appetite
Overtraining in Resistance vs. Endurance Training
Most of the research on overtraining is based on endurance type activities and sports, but research by Fry and Kraemer showed that there are differences in OTS depending on what type of training is undertaken. Specifically, the researchers differentiated between neuroendocrine responses in the classical training volume-induced OTS (increased exercise frequency or more sets) and OTS induced by excessive resistance training intensity (too much resistance/weight for extended periods of time). It appears that the volume-related OTS results in alterations in the testosterone/cortisol ratio, whereas intensity-related OTS results in a marked elevation of exercise-induced catecholamines. Upon reflection, this makes perfect sense as we know that different types of training induce different neuroendocrine responses. The result is that OTS can no longer be viewed as a general term that refers to all types of training due to the different variables.
Overreaching is a systematic attempt to intentionally overstress the body and cause it to adapt short term to the increased training stimulus. It can be thought of as short term overtraining as it involves a brief period of heavy overload without adequate recovery. The main difference between overtraining and overreaching is the time frame spent in a state of overload. Overreaching typically occurs over the period of a month or so but can be induced much quicker if training volume/intensity is dramatically increased for a short period. On the other hand, overtraining typically takes months to set in. An individual can easily recover from overreaching by resting for between two days to a week or so, whereas recovering from overtraining may take several weeks or months. An example of overreaching is where distance runners perform their most mileage three to five weeks prior to competition, then taper for three weeks leading up to the event.
Due to the long term repercussions of OTS, it is critical that coaches, personal trainers and individuals prevent overstepping the mark between overreaching and overtraining. As this mark is often blurred and differs from individual to individual, overreaching should only be practiced by those who know what they are doing. Remember that we don’t know we are overtraining until it has happened! Additionally, it is key that the individual aggressively recovers (either complete rest or a drastic reduction in training volume and intensity) as soon as some of the symptoms (refer to earlier table) appear. In more general terms, we should be looking for things such as decreased performance, decreased training tolerance, decreased motor coordination and an increase in technical faults. We also need to educate our clients/athletes (especially the obsessive ones) about the dangers of OTS.
Something that has not yet been discussed is stress from other sources. It is vital to recognize that all stresses (physical, cognitive or emotional) take their toll on the body as they all result in the release of stress hormones (the catecholamines adrenalin and noradrenalin and, in the case of extreme/prolonged stress, cortisol from the family of glucocorticoids). We all experience different amounts of stress from these three sources, and different recovery strategies are appropriate. Hence, it is critical that our clients/athletes are sufficiently self aware to pinpoint the real source of stress. Coaches and personal trainers who know their clients well can also assist in identifying the source of stress. Below is a table of possible recovery strategies for each source of stress.
||Social support (friends and/or family)
||Classical music (induces relaxing alpha brain waves)
||"Dump pad" (list things that are on your mind)
||Cognitive Behavior Therapy
||Selective attention (focus on what you can change)
|Light aerobic activity (< 50% VO2 max)
In summary, the important thing to remember is that prevention is the key to success when avoiding OTS. We must remember that exercise/training only provides the stimulus for performance improvements. The real adaptations take place when we recover. Therefore, it is crucial that we learn to "train smarter, not harder" because the consequences of overtraining will be devastating to performance and will require a long recovery period. Lastly, we should bear in mind that emotional and cognitive stresses often play a role in OTS, and there is no substitute for close, personal observation and effective communication with our athletes and clients.
- Armstrong, L. & VanHeest, Journal of Sports Medicine 32(3): 185-209, 2002.
- DiFiorni, J., Overuse in children and adolescents. The Physician and Sports Medicine 27(1), 1999.
- Fry, A.C., Kraemer, W.J. Resistance training and overreaching: Neuroendocrine responses. Sports Medicine 23(2): 106-129, 1997.
- Fry, A.C., Overtraining with Resistance Exercise: ACSM’s Current Comments Jan. 2001.
- Gould, D., Greenleaf, C., Guinan, D., Dieffenbach, K., & McCann, S. Pursuing performance excellence: Lessons learned from Olympic athletes and coaches. Journal of Performance Excellence 4: 21-43, 2001.
- Hooper, S.L., L.T. Mackinnon, R.D. Gordon, and Bachmann, A.W. Hormonal responses of elite swimmers to overtraining. Medicine & Science in Sports & Exercise 25:741-747, 1993.
- Lehmann, M., Schnee, W., Scheu, R., Stockhausen, W. and Bachl, N. Decreased nocturnal catecholamine excretion; Parameter of an overtraining syndrome in athletes. International Journal of Sports Medicine 13:236-242, 1992.
- Morgan, W.P., O’Connor, P.B., Ellickson, K.A., & Bradley, P.W. Personality structure, mood states, and performance in elite distance runners. British Journal Sports Medicine 21(3):107-114, 1987.
- Raglin, J.S. & Wilson, G.S. Overtraining in Athletes. In Hanin, Y.L. (Ed.), Emotions in Sport: 191-207. Champaign, IL: Human Kinetics.