Collision activity during training increases total energy expenditure measured via doubly labelled water

• Published in: European journal of applied physiology Vol. 118; no. 6; pp. 1169 - 1177
• Main Authors: Costello, Nessan, Deighton, Kevin, Preston, Thomas, Matu, Jamie, Rowe, Joshua, Sawczuk, Thomas, Halkier, Matt, Read, Dale B., Weaving, Daniel, Jones, Ben
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2018; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Energy expenditure; Human Physiology; Kinematics; Occupational Medicine/Industrial Medicine; Original; Original Article; Recovery (Medical); Sports Medicine; Rugby; Nutrition; Recovery; Contact
• ISSN: 1439-6319; 1439-6327
• DOI: 10.1007/s00421-018-3846-7

Purpose
Collision sports are characterised by frequent high-intensity collisions that induce substantial muscle damage, potentially increasing the energetic cost of recovery. Therefore, this study investigated the energetic cost of collision-based activity for the first time across any sport.
Methods
Using a randomised crossover design, six professional young male rugby league players completed two different 5-day pre-season training microcycles. Players completed either a collision (COLL; 20 competitive one-on-one collisions) or non-collision (nCOLL; matched for kinematic demands, excluding collisions) training session on the first day of each microcycle, exactly 7 days apart. All remaining training sessions were matched and did not involve any collision-based activity. Total energy expenditure was measured using doubly labelled water, the literature gold standard.
Results
Collisions resulted in a very likely higher (4.96 ± 0.97 MJ; ES = 0.30 ± 0.07;
p
 = 0.0021) total energy expenditure across the 5-day COLL training microcycle (95.07 ± 16.66 MJ) compared with the nCOLL training microcycle (90.34 ± 16.97 MJ). The COLL training session also resulted in a very likely higher (200 ± 102 AU; ES = 1.43 ± 0.74;
p
 = 0.007) session rating of perceived exertion and a very likely greater (− 14.6 ± 3.3%; ES = − 1.60 ± 0.51;
p
 = 0.002) decrease in wellbeing 24 h later.
Conclusions
A single collision training session considerably increased total energy expenditure. This may explain the large energy expenditures of collision-sport athletes, which appear to exceed kinematic training and match demands. These findings suggest fuelling professional collision-sport athletes appropriately for the “muscle damage caused” alongside the kinematic “work required”.