Overreaching

Abstract: An imbalance between the overall strain experienced during exercise training and the athlete's tolerance of such effort may induce overreaching or overtraining syndrome. Overtraining syndrome is characterised by diminished sport-specific physical performance, accelerated fatiguability and subjective symptoms of stress. Overtraining is feared by athletes yet there is a lack of objective parameters suitable for its diagnosis and prevention. In addition to the determination of substrates (e.g. lactate, ammonia and urea) and enzymes (e.g. creatine kinase), the possibilities for monitoring of training by measuring hormonal levels in blood are currently being investigated. Endogenous hormones are essential for physiological reactions and adaptations during physical work and influence the recovery phase after exercise by modulating anabolic and catabolic processes. Testosterone and cortisol are playing a significant role in metabolism of protein as well as carbohydrate metabolism. Both are competitive agonists at the receptor level of muscular cells. The testosterone/cortisol ratio is used as an indication of the anabolic/catabolic balance. This ratio decreases in relation to the intensity and duration of physical exercise, as well as during periods of intense training or repetitive competition, and can be reversed by regenerative measures. Correlations have been noted with the training-induced changes of strength. However, it seems more likely that the testosterone/cortisol ratio indicates the actual physiological strain in training, rather than overtraining syndrome. The sympatho-adrenergic system might be involved in the pathogenesis of overtraining. Overtraining appears as a disturbed autonomic regulation, which in its parasympathicotonic form shows a diminished maximal secretion of catecholamines, combined with an impaired full mobilisation of anaerobic lactic reserves. This is supposed to lead to decreased maximal blood lactate levels and maximal performance. Free plasma adrenaline (epinephrine) and noradrenaline (norepinephrine) may provide additional information for the monitoring of endurance training. While prolonged aerobic exercise conducted at intensities below the individual anaerobic threshold lead to a moderate rise of sympathetic activity, workloads exceeding this threshold are characterised by a disproportionate increase in the levels of catecholamines. In addition, psychological stress during competitive events is characterised by a higher catecholamines to lactate ratio in comparison with training exercise sessions. Thus, the frequency of training sessions with higher anaerobic lactic demands or of competition, should be carefully limited in order to prevent overtraining syndrome. In the state of overtraining syndrome and overreaching, respectively, an intraindividually decreased maximum rise of pituitary hormones (corticotrophin, growth hormone), cortisol and insulin has been found after a standardised exhaustive exercise test performed with an intensity of 10% above the individual anaerobic threshold.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract: Overtraining is an imbalance between training and recovery, exercise and exercise capacity, stress and stress tolerance. Stress is the sum of training and nontraining stress factors. Peripheral (short-term overtraining, STO) or peripheral and central fatigue may result (long-term overtraining, LTO). STO lasting a few days up to 2 wk is termed overreaching. STO is associated with fatigue, reduction, or stagnation of the 4 LT performance capacity (performance at 4 mmol lactate or comparable criterion), reduction of maximum performance capacity, and brief competitive incompetence. Recovery is achieved within days, so the prognosis is favorable. LTO lasting weeks or months causes overtraining syndrome or staleness. The symptomatology associated with overtraining syndrome has changed over the last 50 yr from excitation and restlessness (so-called sympathetic form) to phlegmatic behavior and inhibition (so-called parasympathetic form). Increased volume of training at a high-intensity level is likely the culprit. The parasympathetic form of overtraining syndrome dominates in endurance sports. Accumulation of exercise and nonexercise fatigue, stagnation, or reduction of the 4 LT performance capacity, reduction in maximum performance capacity, mood state disturbances, muscle soreness/stiffness, and long-term competitive incompetence can be expected. Complete recovery requires weeks and months, so the prognosis is unfavorable. Other optional or further confirmation requiring findings include changes in blood chemistry variables, hormone levels, and nocturnal urinary catecholamine excretion. Based on the findings reported, recommendations for training monitoring can be made, but their relevance in the practice must still be clarified.

Abstract: Generally speaking, athletes train to increase performance. Performance increases are achieved through increased training loads. Increased loads are tolerated only through interspersed periods of rest and recovery—training periodization. Overreaching is considered an accumulation of training load that leads to performance decrements requiring days to weeks for recovery.14,30 Overreaching followed by appropriate rest can ultimately lead to performance increases.14,30 However, if overreaching is extreme and combined with an additional stressor, overtraining syndrome (OTS) may result.30 OTS may be caused by systemic inflammation and subsequent effects on the central nervous system, including depressed mood, central fatigue, and resultant neurohormonal changes.2,45,46 This article summarizes previous literature and updates the European College of Sport Science’s position statement.30

Abstract: The present investigation compared responses in previously identified physiological, biochemical, and psychological markers of overreaching in triathletes. Sixteen experienced male triathletes (.VO(2max) [mean +/- SD] = 55.7 +/- 4.9 mL . kg (-1) . min (-1), age = 31.3 +/- 11.7 yr) were divided into matched groups according to physical and performance characteristics, and were randomly assigned to either intensified training (IT) or normal training (NT) groups. Physiological, biochemical, and psychological measures were taken at baseline, following four weeks of overload training and following a two-week taper. The IT group completed 290 % greater physical training load than the NT group during the overload period. The subjects completed a 3-km run time trial (3-km RTT) each week in order to assess the time course of change in endurance performance. 3-km RTT performance was significantly reduced (3.7 +/- 7.5 %; p < 0.05) following four weeks of overload training in the IT group confirming a state of overreaching. During the same period, 3-km RTT performance significantly improved in the NT group (3.0 +/- 1.1 %; p < 0.05). Following the two-week taper, 3-km RTT performance significantly improved in the IT group (7.0 +/- 5.6 %; p < 0.05). Hemoglobin concentration significantly decreased and urea increased in both groups during the overload period (p < 0.05). During the taper hemoglobin normalized with a greater increase in the IT group compared to the NT group (p < 0.05). A significant increase in free testosterone to cortisol ratio was also observed in the IT group compared to the NT group during the taper (p < 0.05). No significant changes were observed for any other biochemical variables during the period of investigation. The RESTQ-76 Sport questionnaire showed an impaired recovery-stress state with increased training load, which improved following the taper in the IT group (p < 0.05). These present results suggest that none of the physiological and biochemical variables measured in this study were effective for the early identification of overreaching in experienced triathletes. However, the RESTQ-76 Sport questionnaire may provide a practical tool for recognizing overreaching in its early stages. These findings have implications for monitoring training status in athletes in a practical training setting.