Effects of 21 Days of Intensified Training on Markers of Overtraining

Slivka, DR, Hailes, WS, Cuddy, JS, and Ruby, BC. Effects of 21 days of intensified training on markers of overtraining. J Strength Cond Res 24(10)2604-2612, 2010-The purpose of this study was to impose a period of quantifiable intensified training to determine if commonly used diagnostic markers of overtraining parallel changes in physical performance and thus overtraining status. Eight trained male cyclists (24 ± 1 years, 71 ± 3 kg, O2peak = 4.5 ± 0.1·L·min) performed 21 days (3,211 km) of intensified training in the field where volume and intensity were increased over normal training. Salivary IgA, testosterone, and cortisol, 1-hour time trial performance, heart rate response, and profile of mood states (POMS) were collected and analyzed throughout the 21-day training period. The POMS category vigor declined from day 1 to day 4 and remained lower throughout (p < 0.05). There were no other statistical changes in overtraining parameters. However, individuals who demonstrated 2 or more symptoms of overtraining at any point throughout the 21 days were considered symptomatic and had a lower (p < 0.05) O2peak (4.2 ± 0.1·vs. 4.7 ± 0.1 L·min) and lower (p < 0.05) average workload during the initial 1-hour time trial (253 ± 5 vs. 288 ± 14 W). Interestingly, the 1-hour time trial power in these individuals with symptoms of overtraining did not decline (p > 0.05). These data demonstrate that markers of overtraining do not parallel a decrease in performance and should be interpreted with caution.