Competing at Altitude Reduces In-Match Physical Demands of Professional Soccer Players Compared With Sea Level.

Purpose: This study examined whether physical demands during soccer matches differ between sea level and altitude, considering variations by playing position.

Methods: Thirty-seven professional players were monitored during 22 matches (11 at sea level and 11 at altitudes of 2200-4090 m) with global navigation satellite systems. Independent mean differences were used to compare in-match physical demands (ie, total distance, distance covered at specific speed intervals, accelerations [ACCs] and decelerations [DECs], and maximal speed) between locations for 5 playing positions (central defenders, fullbacks, central midfielders, wide midfielders, and forwards).

Results: At altitude, players covered shorter total distances (P < .001) and less distance in the 14.4- to 19.8-km/h (P < .001), 19.8- to 25.2-km/h (P < .001), and >25.2-km/h (P < .001) speed ranges. They also performed fewer ACCs (2.0-3.5 m/s2, P < .001; 3.5-6.0 m/s2, P < .001) and DECs (-3.5 to -2 m/s2, P < .001; -6.0 to -3.5 m/s2, P < .001) and achieved lower maximal speeds (P < .001). The impact of altitude varied by position: Central midfielders showed reduced performance in all variables, while central defenders (distance > 25.2 km/h, ACCs [2.0 and 3.5 m/s2], DECs [-3.5 and -2.0 m/s2], and maximal speed), fullbacks (distance > 25.2 km/h, ACCs, and DECs [-3.5 and -2.0 m/s2]), and forwards (distances [total, 19.8-25.2 km/h, and >25.2 km/h] and ACCs [-3.5 and -6.0 m/s2]) presented unclear differences (P > .05) between locations.

Conclusion: Our study highlights the importance of considering playing positions when assessing the in-match activity profiles of sea-level resident soccer players competing at moderate to high altitudes.