Metabolic Power in Team Sports - Part 2: Aerobic and Anaerobic Energy Yields

Abstract

A previous approach to estimate the time course of instantaneous metabolic power and O consumption in team sports has been updated to assess also energy expenditure against air resistance and to identify walking and running separately. Whole match energy expenditure turned out ≈14% smaller than previously obtained, the fraction against the air resistance amounting to ≈2% of the total. Estimated net O consumption and overall energy expenditure are fairly close to those measured by means of a portable metabolic cart; the average difference, after a 45 min exercise period of variable intensity and mode, amounting to ≈10%. Aerobic and anaerobic energy yields, metabolic power, energy expenditure and duration of High (HI) and Low (LI) intensity bouts can also be estimated. Indeed, data on 497 soccer players during the 2014/2015 Italian "Serie A" show that the number of HI efforts decreased from the first to the last 15-min periods of the match, without substantial changes in mean metabolic power (≈22 W·kg) and duration (≈6.5 s). On the contrary, mean metabolic power of the LI decreased (5.8 to 4.8 W·kg), mainly because of a longer duration thereof, thus underscoring the need for longer recovery periods between HI.

Metabolic Power in Team Sports - Part 1: An Update

“…Finally, we would like to point out that the approach described above does not take into consideration several specific characteristics of soccer, such as jumps, backwards running, running with the ball, kicking the ball or confronting an opponent. Nevertheless, as discussed in detail in the accompanying paper [12], we think that, in terms of the energetics of a match and provided that it is correctly implemented, this approach yields a picture closer to the "truth" than that emerging from more conventional approaches. ▶Fig.…”

“…We have previously shown that the energy cost of accelerated/decelerated running on flat terrain can be estimated on the basis of the biomechanical equivalence between accelerated/decelerated running on flat terrain and uphill/downhill running at constant speed [5] and that this approach can be applied to soccer and other team sports [13]. Indeed, by monitoring the players' speed at 18.18 Hz by means of a GPS system (GPEXE®), it is possible to estimate energy cost, overall energy expenditure and instantaneous metabolic power of any given player, from which the effective O₂ consumption can also be obtained, as shown in the accompanying paper [12]. However, in soccer as in many other team sports, several walking episodes are interspersed among running bouts.…”

“…In the accompanying paper [12], we will show that this upgraded approach, as incorporated into portable GPS devices, allows one to estimate with reasonable accuracy the time course of metabolic power and actual O 2 uptake. The information thus obtained can be utilized to assess the overall energy expenditure and the fractions thereof derived from aerobic and anaerobic sources, as well as the duration and metabolic power of high-and low-intensity episodes, thus yielding a more accurate picture of the metabolic load than can be obtained from speed and/or acceleration alone.…”

Monitoring Matches and Small-sided Games in Elite Young Soccer Players

“…SSG) is controversial [9][10][11], it has been demonstrated that the MP analysis may be useful to properly assess the physical constraints and especially the high-intensity phases of professional players (i.e. match or training session) [6,8,[12][13][14]. Indeed, the high-intensity phases require an attention to proper monitoring of players' external workload, and are decisive moments that impact the matches [15,16].…”

“…Recently, a metabolic power (MP) approach has been developed to estimate more precisely the energy expenditure of soccer players considering positive and negative accelerations, instantaneous running speed and mechanical parameters of the athletes [6][7][8]. The…”