Monitoring Training in Elite Soccer Players: Systematic Bias between Running Speed and Metabolic Power Data

Abstract

We compared measurements of high-intensity activity during field-based training sessions in elite soccer players of different playing positions. Agreement was appraised between measurements of running speed alone and predicted metabolic power derived from a combination of running speed and acceleration. Data was collected during a 10-week phase of the competitive season from 26 English Premier League outfield players using 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), respectively. We selected 0.2 as the -minimally important standardised difference between methods. Mean training session TS was 478±300 m vs. 727±338 m for TP (p<0.001). This difference was greater for central defenders (~ 85%) vs. wide defenders and attackers (~ 60%) (p<0.05). The difference between methods also decreased as the proportion of high-intensity distance within a training session increased (R2=0.43; p<0.001). We conclude that the high-intensity demands of soccer training are underestimated by traditional measurements of running speed alone, especially in training sessions or playing positions associated with less high-intensity activity. Estimations of metabolic power better inform the coach as to the true demands of a training session.

Positional Match Running Performance in Elite Gaelic Football

“…The current study is the first to differentiate players into the five positional roles. Similar to previous studies in soccer (10,17,21,37) , rugby league (5,6,20) and Australian football (2,15,16,19) positional differences for running performance during elite Gaelic football were observed. Specifically, midfielders covered greater total distance compared to other playing positions, also high speed distances were greater for midfielders as well as half-forwards and half-backs in comparison to full-forwards and full-backs.…”

The application of differential ratings of perceived exertion to Australian Football League matches

“…Nonetheless, the association between high-speed running (total and relative), relative total distance, total metabolic power and relative high power distance with RPE-L was moderate, which we believe provides further support for the discriminate validity of differential RPE's. The incorporation of both velocity and acceleration contributions to external load using the metabolic power approach did not strengthen associations with RPE ratings, which supports recent conclusions drawn by Coutts et al 21 who suggested that metabolic power adds little information to external loading observations in AFL matchplay, perhaps due to the less congested nature of AFL versus Soccer 17,20 or Rugby League. 28 The unclear associations between accelerometer derived indices and RPE ratings may reflect the large between-subject variation in running mechanics.…”

“…However, total energy costs calculated from this model are similar to those derived from physiological measures, 17 and its determination of the instantaneous metabolic cost has demonstrated concurrent 19 and construct validity. 20,21 Therefore, in this study we adopted the metabolic power approach to estimate total match energy expenditure (Energy Expenditure, KJ·kg -1 ) and average metabolic power (Pmet, W·kg -1 ), together with the relative distance covered at a high instantaneous metabolic power (≥ 20 W·kg -1 ). Equivalent Distance (ED; m) was determined to represent the corresponding total distance covered for steady state running to match the estimated energy expenditure.…”

Match Running Performance During Fixture Congestion in Elite Soccer: Research Issues and Future Directions

“…Metabolic power estimations adjust data to incorporate the additional energy cost of acceleration and deceleration activities [27]. Although no studies have yet been conducted, these measures could be a valid means for interpreting changes in performance and subsequently individualising recovery strategies according to a more accurate account of the match loads imposed on players [28]. Indeed, recent research using global positioning systems (10 Hz sampling) in elite players has shown that the distance covered in rapid acceleration/deceleration phases is potentially more sensitive than high-speed distance alone in detecting variations in match running performance [29].…”