Biomechanical and Physiological Responses to 120 Min. of Soccer-Specific Exercise

ABSTRACT

Purpose: The purpose of the study is to investigate biomechanical and physiological responses to soccer-specific exercise incorporating an extra-time period (ET) and assess the test–retest reliability of these responses. Methods: Twelve soccer players performed 120 min of soccer-specific exercise. Tri-axial (PL_Total) and uni-axial PlayerLoad™ in the vertical (PL_V), anterior–posterior (PL_A–P), and medial–lateral (PL_M–L) planes were monitored using a portable accelerometer. Likewise, respiratory exchange ratio (RER) was recorded throughout exercise. At the end of each 15-min period, players provided differential ratings of perceived exertion for legs (RPE-L), breathlessness (RPE-B) and overall (RPE-O), and capillary samples were taken to measure blood lactate (BLa) concentrations. The soccer-specific exercise was completed twice within 7 days to assess reliability. Results: A main effect for time was identified for PL_Total (p = 0.045), PL_V (p = 0.002), PL_A–P (p = 0.011), RER (p = 0.001), RPE-L (p = 0.001), RPE-O (p = 0.003), and CMJ (p = 0.020). A significant increase in PL_Total (234 ± 34 au) and decrease in RER (0.87 ± 0.03) was evident during 105–120 versus 0–15 min (215 ± 25 au; p = 0.002 and 0.92 ± 0.02; p = 0.001). Coefficients of variations were <10% and Pearson’s correlation coefficient demonstrated moderate-to-very strong (0.33–0.99) reliability for all PL variables, RPE-B, BLa, and RER. Conclusions: These results suggest that mechanical efficiency is compromised and an increased rate of lipolysis is observed as a function of exercise duration, particularly during ET. These data have implications for practitioners interested in fatigue-induced changes during ET.

KEYWORDS:

• Football
• PlayerLoad™
• oxygen consumption
• perceived exertion
• fatigue
• reliability

Acknowledgments

The authors gratefully acknowledge the participants who willingly took part in the research.

Author contributions

AF, RMP, and LDH planned the study. AF, RN, and LDC conducted the data collection. AF, MH, SL, and LH completed data analysis. AF wrote the first draft and LDC, MH, RN RMP, and LDH reviewed the manuscript at various stages throughout the editing process and approved the final draft for publication.