Purpose: Recent studies have shown that soccer players’ responses are similar on natural grass (NG) and artificial turf (AT), but they did not control the mechanical properties of these surfaces. This work aimed to analyze the influence of the game surface on amateur soccer players’ physical and physiological responses using a soccer simulation protocol. Methods: A total of 16 amateur players performed 3 bouts of the soccer simulation protocol on AT, and, on another day, 3 bouts on NG. The mechanical properties of both surfaces were recorded. The order of surfaces was randomly established for each participant. Physiological responses of players were assessed before and after the 6-repeated-sprints test existing at the midpoint of each bout. Fatigue (% best; % diff) and general variables (total time; best time, mean time; maximum speed) for both the repeated sprint test (RST) and the agility tests (nonlinear actions at maximum speed) incorporated into the soccer simulation protocol were also analyzed. Results: The 2 surfaces displayed different mechanical properties. Physical responses were found similar for both surfaces (P > .05) before and after the RST. There were no surface differences in sprint times or fatigue variables for the RST (P > .05). The agility test was faster on AT than on NG in bout 1 (average speed [+1.17 km/h;P = .037]; agility test cut time [−0.31 s; P = .027] and best time [−0.52 s; P = .042]). Conclusions: The differences in the mechanical properties of the 2 surfaces are not sufficient to cause differences in the physiological and physical responses of soccer players, although they may affect turns and cuts.
Jorge López-Fernández, Javier Sánchez-Sánchez, Jorge García-Unanue, José Luis Felipe, Enrique Colino and Leonor Gallardo
Enrique Colino, Jorge Garcia-Unanue, Leonor Gallardo, Carl Foster, Alejandro Lucia and Jose Luis Felipe
Purpose: To characterize, for the first time, the mechanical properties of treadmill surfaces along with a practical interpretation of their influence on physiological and perceived demands during endurance running compared with other widely used surfaces such as asphalt and tartan tracks. Methods: Ten experienced male endurance runners performed a 40-minute running bout at a preferred constant speed on 3 different surfaces (after a randomized, counterbalanced order with a 7-d interval between trials): asphalt, tartan, or treadmill. Shock absorption, vertical deformation, and energy restitution were measured for the 3 surfaces. Intensity (based on heart rate data) and rating of perceived exertion were monitored. Results: The values of shock absorption averaged 0.0% (asphalt), 37.4% (tartan), and 71.3% (treadmill), while those of vertical deformation and energy restitution averaged 0.3, 2.2, and 6.5 mm and 90.8%, 62.6%, and 37.0%, respectively. Running intensity (as determined by heart rate data) was higher overall on the treadmill than tartan but not asphalt running. Except for the first 10 minutes, all mean rating of perceived exertion values were significantly higher in asphalt and treadmill than in tartan. No significant differences were identified between treadmill and asphalt. Conclusions: The considerably higher shock absorption of the treadmill than the tartan surface leads to a reduction in the amount of energy returned to the athlete, which in turn increases physiological stress and rating of perceived exertion during endurance running.