title: Soluble tumour necrosis factor receptor-1 (sTNFR1) levels are positively associated with exercise intensity in athletes after strenuous off-road cycling.
abstract: OBJECTIVE
  Strenuous exercise can enhance plasma levels of pro- and anti-inflammatory cytokines. Increases in plasma tumor necrosis factor-alpha (TNF-α) are followed rapidly by a rise in its natural inhibitors, soluble TNF receptors (sTNFRs). These inhibitors likely prevent an over-response to the cytokine. Aims of the present study were: 1) analyze plasma sTNFR1 at different time-points in response to a strenuous off-road cycling competition; 2) evaluate whether plasma levels of sTNFR1 correlate to increased blood lactate levels on completion of the exercise.
  
  
  METHODS
  Eight trained off-road cyclists took part in this study and the data collection occurred during an official off-road race. Blood samples were collected pre-race, immediately post-race, and 1 h, 2 h and 24 h during the recovery period, for plasma sTNFR1 and blood lactate determination.
  
  
  RESULTS
  Increase in sTNFR1 plasma levels were observed immediately post-race, 1 h and 2 h post-race (P<0.01), returning to baseline levels at the end of the recovery period (24 h). Significant correlation between plasma levels of sTNFR1 and blood lactate concentration were observed at the end of the race (r=0.925; P<0.001).
  
  
  CONCLUSIONS
  An off-road cycling race stimulated an increase in plasma sTNFR1 and this anti-inflammatory molecule was positively correlated to blood lactate concentration. This result reinforces the view that exercise intensity influences the increase in plasma anti-inflammatory molecules.
authors: Grupo de Estudos em Saúde e Exercício Universidade Federal de Viçosa, Florestal, MG, Brazil - anaaless@gmail.com.
authors: G A
authors: GA
authors: Pussieldi
authors: E C
authors: EC
authors: Gomes
authors: C E
authors: CE
authors: Veneroso
authors: J A
authors: JA
authors: De Paz
authors: T R
authors: TR
authors: Fonseca
authors: T T
authors: TT
authors: Mendes
authors: A G
authors: AG
authors: Rossi
authors: M M
authors: MM
authors: Teixeira
authors: A L
authors: AL
authors: Teixeira
authors: A L
authors: AL
authors: Alessandri
mesh_terms: D001642:Bicycling / Q000502:physiology*; D003163:Competitive Behavior; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D005082:Physical Exertion / Q000502:physiology*; D010953:Plasma Volume; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000097:blood*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D007773:Lactates; D047888:Receptors, Tumor Necrosis Factor, Type I