Training-overtraining. A prospective, experimental study with experienced middle- and long-distance runners.

Area of Science:

• Sports Science
• Exercise Physiology
• Endocrinology

Background:

• Overtraining syndrome is a significant cause of performance stagnation in athletes.
• It can manifest as either parasympathetic (inhibition) or sympathetic (excitation) overtraining.
• Understanding the physiological impact is crucial for athlete health and performance.

Purpose of the Study:

• To induce overtraining syndrome in middle- and long-distance runners.
• To examine the effects of increased training volume on cardiovascular, metabolic, and hormonal parameters.
• To specifically analyze plasma and urinary catecholamine responses to overtraining.

Main Methods:

• 8 experienced middle- and long-distance runners underwent a 4-week training increase, peaking at 174.6 km/week.
• Cardiovascular, metabolic, and hormonal markers were assessed via laboratory testing, including graded treadmill running.
• Measurements were taken at baseline, day 14, and day 28 of the intensified training period.

Main Results:

• A decrease in maximum working capacity and stagnation in endurance performance were observed in most athletes.
• Subjective complaints significantly increased, alongside notable decreases in glucose, lactate, albumin, and heart rate.
• Elevated creatine phosphokinase (CPK) and stable levels of urea, creatinine, and liver enzymes were recorded.

Conclusions:

• The study successfully induced overtraining syndrome, demonstrating its negative impact on performance and physiological markers.
• Significant metabolic and cardiovascular alterations occurred, highlighting the body's stress response to excessive training.
• These findings underscore the importance of monitoring athletes for overtraining to prevent performance decrements and health issues.