A comparison of displacement and energetic variables between three team sport GPS devices

Effect of the role, playing position and the body characteristics on physical performance in female soccer players

The aims of this study were to know the physical demands according to the playing position and team role, and to assess the effect of the body characteristics on the physical performance of semi-professional female soccer players. Forty-five female semi-professional soccer players during 9 home-matches of the 2021-2022 season were analyzed and GPS devices (GPEXE ®) were used. ANCOVA tests were performed with playing time as covariate. The results showed greater physical demands in forwards and wide-midfielders and offensive role players. Total distance, metabolic power, accelerations, deaccelerations, and distance covered to medium and high speed obtained a strong effect size in these analyses according to the playing position. Furthermore, relationships between body weight and physical performance were found (p < 0.05). In conclusion, the main finding of this study showed that semi-professional female soccer players compete differently, caused by differentiated functions, evidenced in the playing positions and role in the team. Offensive role, forwards and wide-midfielder female players performed the highest physical demands in the competition. This study has shown relevant information for coaches, S&C coaches, and training staff of the semi-professional female soccer teams in order to propose new keys and ways of planning training sessions.

Match running performance profiles of amputee football players at the national level

Even though running performance and positional profiles in football are well described, amputee football (AF) has different characteristics of the movement, pitch dimensions, and time played. There is a gap in the scientific literature about positional profiles based on running performance in AF. This study aimed to investigate the differences between positions, the influence of the amputation level or defect of the lower limb (LD), the differences in running performance between halves, and the relationship with the final match result. Thirteen AF National Team players were monitored by Global Navigation Satellite System (GNSS), tracking 24 official international matches for 17 months. Values of top speed, peak acceleration, peak deceleration, average distance per minute, sprint mean speed, GPS load per minute, inertial load per minute (Gs load/min), number of sprints per minute, and a number of impacts per minute were analyzed for defenders (DEF), midfielders (MID) and forwards (FOR). Additional factors analyzed were amputation level (below the knee, low amputation-LA or over the knee, high amputation-HA or defect of the lower limb-LD) and the match's final result. Midfielders had significantly higher running performance parameters compared to other positions (greater top speed than DEF (+ 0.3 m/s; p < 0.001) and FOR (+ 0.2 m/s; p = 0.045), greater peak acceleration and deceleration than DEF (+ 0.5 m/s2 for both measures; p < 0.001) and FOR (+ 0.4 and + 0.3 m/s2; p < 0.001 and p = 0.036, respectively), greater GPS load/minute than DEF (+ 0.2 load/min; p = 0.001) and FOR (+ 0.3 load/min; p < 0.001), greater Gs load per minute than DEF (+ 2.7 load/min; p < 0.001) and FOR (+ 1.8 load/min; p < 0.001), greater number of impacts per minute than DEF (+ 0.2 n/min; p < 0.001) and FOR (+ 0.2 n/min; p < 0.001). Players with LD had significantly higher running performance than those with LA or HA. In the match's second half, a decrease in running performance was registered. The trend of running more when losing could be observed-AF players had higher running parameters in lost matches, but the differences were not statistically significant. Further research complied with contextual game analysis is needed to assess the running performance of AF players deeply.

Assessment of Pain and External Load in Amputee Football Using Digital Pain Drawing and GNSS Tracking—A Pilot Study

Amputee Football (AF) players move using lofstrand crutches (LC) and a single leg during training and matches, which may expose them to excessive loads. Due to a lack of scientific articles describing these issues, this pilot study aims to gain insight into the assessment of pain experiences, as well as external loads during training and matches in AF. An observational study design was followed. Twelve male AF players (2 goalkeepers—GK and 10 field players—FP), 29.9 ± 8.7 years, stature 178.3 ± 6.5 cm, body mass 77.2 ± 8.9 kg were involved in the study. After stature and body mass measures, participants filled out the questionnaire for pain. The players were familiarized with digital pain drawing (DPD). Afterwards, they reported pain typically felt in relation to regular AF training and playing matches—recall pain (RP). During a two-day training camp (TC) with two training sessions each day and during a two-day international tournament (IT) with two matches each day, the players were monitored using DPD, rate of perceived exertion (RPE) and overall pain level (OPL) scales. In addition, during an international tournament (IT), match players were monitored using a GNSS tracking system for external load assessment. All of the participants reported multiple locations of pain after AF training or a match. The area of recall pain (RP) was the highest: +0.5% when compared to the end of TC and +43% when compared to end of IT. The pain area registered at the end of IT was significantly lower (p = 0.028) compared to RP and lower without statistical significance when compared to the end of TC. Average RPE was 3.31 ± 1.38 and average OPL was 2.86 ± 1.81 in 0–10 scale. Typical RPE was higher than that registered at the end of IT. Also typical OPL was higher compared to that registered after the end of TC, which was higher than after the end of IT. The average distance covered by a FP during a match ranged from 2483.14 ± 583.64 m to 2911.08 ± 828.90 m. AF field players suffered pain as a consequence of training and matches. The loads coming from playing and training, combined with pain, may lead to injuries. Further research directions should include assessments of the relationship of pain characteristics, injuries and GNSS tracking parameters.

Accuracy of Tracking Devices' Ability to Assess Exercise Energy Expenditure in Professional Female Soccer Players: Implications for Quantifying Energy Availability

The purpose of the study was to assess the accuracy of commonly used GPS/accelerometer-based tracking devices in the estimation of exercise energy expenditure (EEE) during high-intensity intermittent exercise. A total of 13 female soccer players competing at the highest level in Norway (age 20.5 ± 4.3 years; height 168.4 ± 5.1 cm; weight 64.1 ± 5.3 kg; fat free mass 49.7 ± 4.2 kg) completed a single visit test protocol on an artificial grass surface. The test course consisted of walking, jogging, high-speed running, and sprinting, mimicking the physical requirements in soccer. Three commonly used tracking devices were compared against indirect calorimetry as the criterion measure to determine their accuracy in estimating the total energy expenditure. The anaerobic energy consumption (i.e., excess post-exercise oxygen consumption, EPOC) and resting time were examined as adjustment factors possibly improving accuracy. All three devices significantly underestimated the total energy consumption, as compared to the criterion measure (p = 0.022, p = 0.002, p = 0.017; absolute ICC = 0.39, 0.24 and 0.30, respectively), and showed a systematic pattern with increasing underestimation for higher energy consumption. Excluding EPOC from EEE reduced the bias substantially (all p's becoming non-significant; absolute ICC = 0.49, 0.54 and 0.49, respectively); however, bias was still present for all tracking devices. All GPS trackers were biased by showing a general tendency to underestimate the exercise energy consumption during high intensity intermittent exercising, which in addition showed a systematic pattern by over- or underestimation during lower or higher exercising intensity. Adjusting for EPOC reduced the bias and provided a more acceptable accuracy. For a more correct EEE estimation further calibration of these devices by the manufacturers is strongly advised by possibly addressing biases caused by EPOC.

Physical Demands of Women's Soccer Matches: A Perspective Across the Developmental Spectrum

Female soccer players are exposed to specific physical demands during matches, which vary according to the standard of play. Existing studies have largely focused on quantifying the distances covered for professional and international level players. This approach is limited in scope regarding the broader aspects around physical demands and is detached from development pathway models. An understanding of the demands across all standards will provide valuable insights about appropriate player development and help ensure physical readiness for the demands of the sport. The aim of this perspective paper is to describe the physical demands experienced during women's soccer matches across the developmental spectrum. A combination of evidence from the literature and data from the author's research (JDV) is presented. Specifically highlighted are the trends for locomotor distances, acceleration and deceleration frequency, and metabolic power metrics for youth (≤U17), college (NCAA/U20), professional (domestic) and international standards of women's soccer. In addition, the changes in match demands between levels of play are used to help illustrate gaps that must be overcome in order to successfully achieve physical readiness to compete at higher levels. The evidence demonstrates the importance of training appropriate attributes to prepare female soccer players who are striving to play at progressively higher standards.

How does the mid-season coach change affect physical performance on top soccer players?

The aim of this study was to analyze the locomotion and metabolic responses of professional players in the top three competitive standards of Spanish soccer (First, Second and Second 'B' division) during the four weeks before and after dismissal the coach. Training and match load data were analyzed separately (n = 1189 events) by coach (dismissed coach and the new coach) and Wilcoxon-test was performed to compare data between coaches. In training, players covered longer distance in all speed ranges >14 km•h ^- 1 with the coach dismissed; medium (14-18 km•h ^- 1), high (18-21 km•h ^- 1), very-high (21-24 km•h ^- 1) and sprint running distance (>24 km•h ^- 1) (d = 0.53, 0.46, 0.58 and 0.54; respectively) on first division; and equivalent distance index and accelerations events (d = 0.63 and 0.50; respectively) on second division. Lower differences were found in matches, in which the dismissed coach showed higher equivalent distance index, accelerations and decelerations events (d = 0.69, 0.68 and 0.61; respectively) compared to the new coach in the second division. Therefore, the players covered longer high-intensity distance with the dismissed coach than the new coach in training, whilst a similar performance was found in the competition. These results suggest that the coach turnover at mid-season did no increase the players' physical performance either in training or in competition.

Metabolic Power: A Step in the Right Direction for Team Sports

The ability of the "metabolic power" model to assess the demands of team-sport activity has been the subject of some interest-and much controversy-in team-sport research. Because the cost of acceleration depends on the initial speed and the costs of acceleration and deceleration are not "equal and opposite," changes in speed must be accounted for when evaluating variable-speed locomotion. The purpose of this commentary is to address some of the misconceptions regarding "metabolic power," acknowledge its limitations, and highlight some of the benefits that energetic analysis offers over alternative approaches to quantifying the demands of team sports.