title: The influence of recovery and training phases on body composition, peripheral vascular function and immune system of professional soccer players.
abstract: Professional soccer players have a lengthy playing season, throughout which high levels of physical stress are maintained. The following recuperation period, before starting the next pre-season training phase, is generally considered short but sufficient to allow a decrease in these stress levels and therefore a reduction in the propensity for injury or musculoskeletal tissue damage. We hypothesised that these physical extremes influence the body composition, blood flow, and endothelial/immune function, but that the recuperation may be insufficient to allow a reduction of tissue stress damage. Ten professional football players were examined at the end of the playing season, at the end of the season intermission, and after the next pre-season endurance training. Peripheral blood flow and body composition were assessed using venous occlusion plethysmography and DEXA scanning respectively. In addition, selected inflammatory and immune parameters were analysed from blood samples. Following the recuperation period a significant decrease of lean body mass from 74.4+/-4.2 kg to 72.2+/-3.9 kg was observed, but an increase of fat mass from 10.3+/-5.6 kg to 11.1+/-5.4 kg, almost completely reversed the changes seen in the pre-season training phase. Remarkably, both resting and post-ischemic blood flow (7.3+/-3.4 and 26.0+/-6.3 ml/100 ml/min) respectively, were strongly reduced during the playing and training stress phases, but both parameters increased to normal levels (9.0+/-2.7 and 33.9+/-7.6 ml/100 ml/min) during the season intermission. Recovery was also characterized by rising levels of serum creatinine, granulocytes count, total IL-8, serum nitrate, ferritin, and bilirubin. These data suggest a compensated hypo-perfusion of muscle during the playing season, followed by an intramuscular ischemia/reperfusion syndrome during the recovery phase that is associated with muscle protein turnover and inflammatory endothelial reaction, as demonstrated by iNOS and HO-1 activation, as well as IL-8 release. The data provided from this study suggest that the immune system is not able to function fully during periods of high physical stress. The implications of this study are that recuperation should be carefully monitored in athletes who undergo intensive training over extended periods, but that these parameters may also prove useful for determining an individual's risk of tissue stress and possibly their susceptibility to progressive tissue damage or injury.
authors.affiliation: Division of Applied Cachexia Research, Department of Cardiology, Charité Universitätsmedizin Berlin, CVK, Berlin, Germany. simon.reinke@charite.de
authors.forename: Simon
authors.initials: S
authors.lastname: Reinke
authors.forename: Tim
authors.initials: T
authors.lastname: Karhausen
authors.forename: Wolfram
authors.initials: W
authors.lastname: Doehner
authors.forename: William
authors.initials: W
authors.lastname: Taylor
authors.forename: Kuno
authors.initials: K
authors.lastname: Hottenrott
authors.forename: Georg N
authors.initials: GN
authors.lastname: Duda
authors.forename: Petra
authors.initials: P
authors.lastname: Reinke
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Volk
authors.forename: Stefan D
authors.initials: SD
authors.lastname: Anker
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D001808:Blood Vessels / Q000502:physiology*; D001823:Body Composition; D006801:Humans; D007107:Immune System / Q000502:physiology*; D008297:Male; D012039:Regional Blood Flow; D012916:Soccer / Q000502:physiology*