Int J Sports Med 2019; 40(12): 762-767
DOI: 10.1055/a-0985-4464
Physiology & Biochemistry
© Georg Thieme Verlag KG Stuttgart · New York

C-Reactive Protein Serum Levels as an Internal Load Indicator of Sprints in Competitive Football Matches

Pedro Jatene
1   Group of Study and Research in Exercise Science (GEPECEF), Universidade Municipal de Sao Caetano do Sul, Sao Caetano do Sul, Brazil
,
Gustavo Silva dos Santos
1   Group of Study and Research in Exercise Science (GEPECEF), Universidade Municipal de Sao Caetano do Sul, Sao Caetano do Sul, Brazil
,
Daniel Leite Portella
2   School of Physical Education - Group of Study and Research in Exercise Science (GEPECEF), Universidade Municipal de Sao Caetano do Sul, Sao Caetano do Sul, Brazil
› Author Affiliations
Further Information

Publication History



accepted 22 July 2019

Publication Date:
29 August 2019 (online)

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Abstract

This study compared internal load variable dynamics across three consecutive football matches and investigated its relationship with the number of sprints performed by players. Twenty-three male players had blood and salivary samples collected for hormonal concentration (testosterone, cortisol, and testosterone-cortisol ratio), and serum analysis (interleukin-6, interleukin-1-beta, and c-reactive-protein), respectively. Sprints were measured through Global Position System devices. Testosterone and testosterone-cortisol-ratio presented a decreasing behavior up to the second match, and all other indicators presented an increasing behavior during the same period, c-reactive-protein was the only indicator observed to significantly rise up to the third match as well (0.38±0.02 mg/L; 0.49±0.05 mg/L; 0.69±0.05 mg/L; 0.89±0.08 mg/L). C-reactive-protein showed strong correlations with sprints in the second and third matches (p<0.01, r=0.71 and 0.79), and weak-to-moderate in the first one (p<0.05, r=0.59). Interleukin-6 and interleukin-1-beta presented weak-to-moderate correlation in every match (p<0.05, r=0.48 to 0.51; r=0.51 to 0.55) while testosterone-cortisol ratio presented weak-to-moderate correlation only in the third one (p<0.05, r=0.42). Multilevel linear regression showed that c-reactive-protein had a higher R2 than other biomarker in any regression model (R2=0.624; p<0.001). Therefore, c-reactive-protein can be a valid and reliable indicator of sprinting in competitive football. Future research should explore longer periods of monitoring and/or others external load variables so that other behaviors may arise to knowledge.