Overtraining effects on performance

If you want to prevent staleness and overtraining, keep a record of your quality of sleep and levels of fatigue

To perform at a higher level, most dedicated athletes increase their volume and intensity of training during a training season. However, when these increases occur before the athletes’ bodies are ready to handle them, or when they take place without sufficient recovery, the increased-training strategy can backfire, with chronic fatigue and decreases in performance – not performance improvements – the end result.

When athletes enter such periods of reduced performances, they are said to be ‘stale’. No sport has an exclusive right to staleness, with cyclists, basketball players, boxers, runners, swimmers, gymnasts, rowers, wrestlers, and a variety of other athletes all susceptible to the malady. A considerable amount of scientific effort has gone into identifying ‘warning signs’ of staleness – identifiable physiological markers which might appear before staleness is actually reached, markers which could be used by athletes to cut back on their training before they become stale.

To date, this research hasn’t been particularly successful. Various investigators have suggested that changes in morning heart rate, alterations in heart rate during exercise, rises in blood pressure, or shifts in enzymes or hormone levels might be good markers of impending staleness. Unfortunately, such indicators seem to predict staleness without a great deal of reliability, may appear after staleness is already reached, or are difficult for individual athletes to monitor. For example, sex-hormone levels often drop and cortisol levels often rise as athletes begin to become stale, but how many athletes have the time – or ability – to assess their blood-sex-hormone and cortisol levels on a daily basis?

How Australian swimmers rate themselves Now, researchers at the University of Queensland in Australia have identified a simple, apparently reliable way to predict staleness. Their study tracked 14 elite swimmers (five males and nine females) over the course of a six-month training season. During the season, the swimmers completed 10 to 12 workouts per week, with Sunday reserved for complete rest. Over the entire season, the Queensland researchers had the swimmers keep training logs, with entries made each morning after waking up. The swimmers subjectively rated their quality of sleep, fatigue, stress, and muscle soreness on a scale of 1-7. A rating of ‘1’ was a good rating, meaning an athlete had slept extremely well or perceived almost no stress, soreness, or fatigue. At the other end, a score of ‘7’ was extremely bad, indicating terrible sleep, high stress, extreme fatigue and muscle soreness.

Several swimmers became stale during the season, with their performance times slowing by up to 4 per cent, and the logbook recordings of these swimmers were considerably different from the entries made by swimmers who did not become stale. For example, early in the season, swimmers who subsequently became stale recorded higher than usual ratings of muscle soreness and stress, compared to swimmers who stayed fresh. These ratings tended to stay between 3 and 4 (on the 7-point scale) for swimmers who avoided staleness but rose to 5-6 for swimmers who eventually were stale.

In mid-season, the story was a bit different, with ratings of sleep quality and fatigue becoming the dominant predictors of staleness. Again, sleep ratings hovered around 3 for non-stale swimmers but rose to almost 5 for athletes who became stale. Likewise, fatigue stayed below 4 for the high-performing swimmers but ascended above 5 for those who became burned-out. Late in the season, stress became the best indicator, rising to almost 6 for individuals who became stale but staying below 4 for others.

There were some other surprising predictors of staleness. High blood-neutrophil counts were an indicator of staleness in the early season and during the tapering period at the end of the season (neutrophils are a key kind of white blood cell which can easily be counted through routine blood analysis). High blood adrenaline (epinephrine) levels were also predictive of staleness in the early and late parts of the season. However, collecting appropriate blood samples and analysing blood for adrenaline can be time-consuming and costly.

Stay in ‘the threes’
The bottom line? Athletes can probably lower their susceptibility to staleness by keeping careful daily records of their quality of sleep and feelings of fatigue, stress, and muscle soreness on a seven-point scale. Normally, these ratings will settle at below 4 during the season – when an athlete is recovering well from workouts and staleness is not impending. However, when any of these ratings rise to around 5 or above for more than a few days, it may be wise for athletes to cut back on their training until they’re ‘in the threes’ again. A return to ratings below 4 is a good sign that an athlete has recovered well from previous tough training and is now ready for more serious work.

In addition, the Queensland researchers felt that increases in feelings of fatigue and decreases in quality of sleep were particularly valid markers of impending staleness in the mid-season. These changes actually preceded staleness by SEVERAL WEEKS in the stale swimmers, giving athletes who monitor their sleep quality and fatigue ample time to reduce their training and avoid the overtrained state.

(‘Markers for Monitoring Overtraining and Recovery,’ Medicine and Science in Sports and Exercise, vol. 27(1), pp. 106-112,1995)

Owen Anderson

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