Relationship Between Inflammatory Cytokines and Self-Report Measures of Training Overload

Abstract

It has been purported that inflammatory cytokines may be responsible for the aetiology of overtraining. The aim of the present study was to investigate the relationship between self-reported measures of overtraining and inflammatory cytokines. Eight elite male rowers were monitored in their natural training environment for 8 weeks prior to the 2007 Rowing World Championships. During this period of intense endurance training, self-report measures of overtraining and inflammatory cytokines (Interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12p70, and Tumor Necrosis Factor (TNF)-α) were assessed fortnightly. Consistent with previous findings, proinflammatory cytokines IL-1β and TNF-α were significantly associated (p ≤ 0.05) with measures of depressed mood, sleep disturbances, and stress. Similarly, IL-6 was significantly associated (p ≤ 0.01) with measures of depressed mood, sleep disturbances, and fatigue. These results are consistent with previous hypotheses describing how overtraining may be caused by excessive cytokine release, and lend further support for a cytokine hypothesis of overtraining.

KEYWORDS:

• interleukins
• fatigue
• overreaching
• rowing
• depressed moods

The authors acknowledge the invaluable statistical advice received from Mr. Kevin Murray at The University of Western Australia School of Mathematics and Statistics, Statistical Consultation Group. Furthermore, we acknowledge that the sample analysis was carried out using facilities at the Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, which are supported by university, state and federal government funding.

Notes

¹ Confidentiality agreements with the coaching staff preclude us from describing the training program in more detail.