Plasma IL-6 concentration during ultra-endurance exercise

• Published in: European journal of applied physiology 2011-06, Vol.111 (6), p.1081-1088
• Main Authors: Wallberg, Linnea, Mikael Mattsson, C., Enqvist, Jonas K., Ekblom, Björn
• Format: Article
• Language: English
• Subjects: Adult; adventure race; Athletes; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Blood; Cytokine; Cytokines; endurance; Exercise - physiology; Exercise intensity; Exercise Test - methods; Female; Fundamental and applied biological sciences. Psychology; Fysiologi; Fysiologi och farmakologi; Human Physiology; Humans; Idrott; immune response; Immune system; INTERDISCIPLINARY RESEARCH AREAS; Interleukin-6 - analysis; Interleukin-6 - blood; Male; MEDICIN; Medicin och hälsovetenskap; Medicin/Teknik; MEDICINE; Medicine/Technology; Metabolism; Occupational Medicine/Industrial Medicine; Original Article; Osmolar Concentration; Physical Endurance - physiology; Physical Exertion - physiology; Physical fitness; Physiology; Physiology and pharmacology; Plasma; Sports; Sports Medicine; Time Factors; TNF-α; Tumor necrosis factor-TNF; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-010-1737-7

Interleukin 6 (IL-6) response was studied during two ultra endurance events—one laboratory 24 h protocol (9 men) with exercise intensity set to 60% of VO 2max and one Adventure Race over 6 days (12 men/6 women) with a self-selected race pace, including rests, of about 38% of VO 2max . In the 24-h protocol IL-6 level was elevated from 0.76 ± 0.48 pg mL −1 at rest to 7.16 ± 2.70 pg mL −1 at 6 h, and increased further to 10.58 ± 1.04 pg mL −1 at 12 h, but remained thereafter unchanged at 24 h, (10.89 ± 0.36 pg mL −1 ). All participants had nearly identical values at 12 and 24 h, supporting intensity as main determinant in the IL-6 response during prolonged exercise since exercise duration did not increase IL-6 level after 12 h. Possible confounding factors do not seem to influence the IL-6 concentration during the longer races (>12 h), but might very well do so during shorter exercise bouts. In the 6-day race IL-6 increased from rest to 24 h, but thereafter there was no change in plasma IL-6 value until the end of the race (mean 143.5 h). There was no elevation of TNF-α in any of the protocols, suggesting that the competitors were free from systemic inflammation. We conclude that during endurance exercise lasting >12 h intensity, and not duration, is the main determinant of the IL-6 response, while during shorter exercise bouts both intensity and duration contribute to the accumulation of IL-6 in plasma.