Muscle oxygenation response during duplicate sprints in professional football players: an original investigation

Football requires repeated sprint ability for game-changing moments; however, the demand on the skeletal muscles is unknown. The aim of the current study was to determine the muscle oxygen response during duplicate sprints in professional footballers. Eight male professional footballers (age: 29 ± 5 y; height: 181 ± 8 cm; weight: 78 ± 8 kg) were recruited. Participants wore their normal GPS unit and completed their normal match warm-up before near-infrared monitors were attached to the rectus femoris and bicep femoris muscles. Participants then completed two 30 m sprints with 10 s of recovery, while GPS data and muscle oxygenation were recorded. Max speed was unaltered across the two sprints (s1: 8.4 ± 0.3 m.s⁻¹; s2: 8.4 ± 0.4 m.s⁻¹), but max acceleration (s1: 5.0 ± 1.5 m.s⁻²; s2: 3.7 ± 1.2 m.s⁻²) and time to max acceleration (s1: 1.0 ± 0.3 s; s2: 1.8 ± 0.8 s) were significantly different in sprint 2 compared with sprint 1. Change in muscle oxygenation was greater in the bicep femoris muscle than in the rectus femoris muscle in sprint 1 (right BF: 37.0 ± 14.7%; right RF: 23.4 ± 14.8%). Time to fast delay was longer in sprint 2 than in sprint 1 in the bicep femoris muscle (right BFs1: 1.6 ± 1.2 s; right BFs2: 5.2 ± 2.3 s), reflecting different recovery kinetics in the two muscles. During duplicate sprints there is a difference in oxygen response between the two muscles, and the overall recovery of the bicep femoris is much slower. This suggests poorer conditioning of the bicep femoris muscle, which may impact injury risk in professional football players.