Overtraining syndrome (OTS) is a state of excessive training stress combined with fatigue and inadequate recovery. Over time, this leads to a decline in performance.
Signs and symptoms of overtraining
Reduced strength and power output
Chronic fatigue and sleep disturbances
Increased cortisol and decreased testosterone
Elevated resting heart rate
Decreased motivation and mental fatigue
Higher injury risk
Types of overtraining
Functional overreaching (FOR): Temporary fatigue that resolves with adequate recovery.
Non-functional overreaching (NFOR): More severe fatigue that can last weeks.
Overtraining syndrome (OTS): Chronic performance decline lasting months or longer.
OTS can occur, but it’s relatively rare. Non-functional overreaching is more common and is the bigger concern for most athletes.
Ensure proper recovery: Prioritize sleep, nutrition, and rest days.
Use periodization: Cycle training intensity and volume to reduce burnout risk.
Track performance indicators: Watch for declining strength, mood changes, and elevated RHR.
The overtraining continuum
Overtraining develops in stages, as shown in the figure below.
Overtraining continuum
Acute fatigue (days): Temporary performance reduction that typically resolves with short-term recovery.
Functional overreaching (FOR) (days to weeks): Short-term fatigue with a temporary decline in performance, followed by supercompensation if managed properly.
Non-functional overreaching (NFOR) (weeks to months): Extended fatigue with diminishing performance returns and a prolonged recovery time.
Overtraining syndrome (OTS) (months to years): Severe, chronic fatigue with persistent performance decline and systemic physiological dysfunction.
Signs and symptoms of overtraining
Overtraining can affect multiple body systems, including:
Altered catecholamines (epinephrine/norepinephrine): Can increase stress responses and impair recovery.
Monitoring hormonal changes can help identify early signs of overtraining.
Psychological factors in overtraining
Mood disturbances are a reliable indicator of overtraining. Symptoms include:
Decreased motivation & confidence
Increased irritability & anxiety
Poor concentration & cognitive fatigue
Regular psychological assessments, such as the Profile of Mood States (POMS), can help detect mental fatigue before physical performance declines.
Detraining: The reversal of adaptations
Detraining is the loss of physiological adaptations due to a reduced training stimulus. It occurs when an athlete significantly reduces training or stops training altogether.
Effects of detraining
Adaptation
Timeframe of loss
Strength
Gradual loss after 2-4 weeks, but retained longer than endurance
Muscle hypertrophy
Noticeable loss after 3-6 weeks
Neuromuscular efficiency
Declines after 2-3 weeks of inactivity
Cardiovascular fitness (VO₂ Max)
Drops 4-14% in 2-4 weeks, significant loss after 8+ weeks
Glycolytic/Anaerobic capacity
Decreases within 4-6 weeks
Tendon/Bone density
Structural adaptations persist longer but weaken over months of inactivity
Detraining effects are influenced by:
Training history: Well-trained athletes retain strength and neuromuscular adaptations longer.
Duration of inactivity: The longer the detraining period, the greater the loss of muscle size, strength, and endurance.
Type of training cessation: A complete stop in training causes faster performance decline than reduced frequency or intensity.
Strategies to minimize detraining effects
Maintain low-volume, high-intensity training: 1-2 weekly strength sessions can preserve muscle mass and strength.
Use cross-training: Different physical activities can help maintain cardiovascular and muscular fitness.
Gradual return to training: Avoid excessive volume/intensity increases after an extended break.
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