Int J Sports Med 2014; 35(06): 489-493
DOI: 10.1055/s-0033-1355418
Training & Testing
© Georg Thieme Verlag KG Stuttgart · New York

Systematic Bias between Running Speed and Metabolic Power Data in Elite Soccer Players: Influence of Drill Type

P. Gaudino
1  Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
2  Department of Biomedical Sciences for Health, Università degli Studi di Milano, Italy
,
F. M. Iaia
2  Department of Biomedical Sciences for Health, Università degli Studi di Milano, Italy
,
G. Alberti
2  Department of Biomedical Sciences for Health, Università degli Studi di Milano, Italy
,
R. D. Hawkins
1  Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
A. J. Strudwick
1  Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
,
W. Gregson
1  Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
3  ASPIRE, Academy for Sports Excellence, Doha, Qatar
› Author Affiliations
Further Information

Publication History



accepted after revision 23 August 2013

Publication Date:
28 October 2013 (eFirst)

Abstract

The aims of the present study were to: i) evaluate the agreement between estimates of high-intensity activity during soccer small-sided games (SSGs) based on running speed alone and estimated metabolic power derived from a combination of running speed and acceleration; ii) evaluate whether any bias between the 2 approaches is dependent upon playing position or drill characteristics. 3 types of SSGs (5vs5, 7vs7 and 10vs10) were completed by 26 English Premier League outfield players. A total of 420 individual drill observations were collected over the in-season period using portable global positioning system technology. High-intensity activity was estimated using the total distance covered at speeds>14.4 km · h−1 (TS) and the equivalent metabolic power threshold of > 20 W · kg−1 (TP). We selected 0.2 as the minimally important standardised difference between methods. High-intensity demands were systematically higher (~100%, p<0.001) when expressed as TP vs. TS irrespective of playing position and SSG. The magnitude of this difference increased as the size of SSG decreased (p<0.01) with a difference of ~200% observed in the 5vs5 SSG. A greater difference between TP and TS was also evident in central defenders compared to other positions (p<0.05) particularly during the 5vs5 SSG (~350%). We conclude that the high-intensity demands of SSGs in elite soccer players are systematically underestimated by running speed alone particularly during “small” SSGs and especially for central defenders. Estimations of metabolic power provide a more valid estimation as to the true demands of SSGs.