Svein Arne Pettersen

Does a variation in self-reported physical activity reflect variation in objectively measured physical activity, resting heart rate, and physical fitness? Results from the Tromsø study

Aims: To study the association between self-reported physical activity (PA) and objectively measured PA, resting heart rate, and physical fitness. Methods: During 2007—08, 5017 men and 5607 women aged 30—69 years attended the sixth survey of the Tromsø study. Self-reported PA during leisure-time and work were assessed and resting heart rate was measured. In a sub-study, the activity study, PA (Actigraph LLC) and physical fitness (VO2max) were objectively measured among 313 healthy men and women aged 40—44 years. Results: Self-reported leisure PA was significantly correlated with VO2max (ml/kg/min) (women 0.40, p < 0.001, men 0.44 p < 0.001) and moderate-to-vigorous PA (>2000 counts/min) (women 0.28, p < 0.01, men 0.25, p < 0.01). The intra-class correlation coefficient between self-reported leisure PA and overall PA (counts/min) measured by accelerometer was 0.62 (95% CI 0.51, 0.71) for women and 0.59 (95% CI 0.47, 0.69) for men, and for VO2max the intra-class correlation coefficient was 0.86 (95% CI 0.81, 0.90) for both sexes. Among all participants, an inverse dose—response relationship was observed between self-reported leisure PA and resting heart rate for both men and women (p < 0.0001). More women than men met the international recommendations of 10,000 step counts/day (27% vs. 22%) and the recommendation of at least 30 minutes/day of moderate-to-vigorous intensities (30% vs. 22 %). Conclusions: The Tromsø physical activity questionnaire has acceptable validity and provides valid estimates of high-intensity leisure activity. However, these results underscore the need for collecting objectively PA measurements in large epidemiological studies.

Soccer video and player position dataset

This paper presents a dataset of body-sensor traces and corresponding videos from several professional soccer games captured in late 2013 at the Alfheim Stadium in Tromsø, Norway. Player data, including field position, heading, and speed are sampled at 20Hz using the highly accurate ZXY Sport Tracking system. Additional per-player statistics, like total distance covered and distance covered in different speed classes, are also included with a 1Hz sampling rate. The provided videos are in high-definition and captured using two stationary camera arrays positioned at an elevated position above the tribune area close to the center of the field. The camera array is configured to cover the entire soccer field, and each camera can be used individually or as a stitched panorama video. This combination of body-sensor data and videos enables computer-vision algorithms for feature extraction, object tracking, background subtraction, and similar, to be tested against the ground truth contained in the sensor traces.

Caffeine supplementation does not affect match activities and fatigue resistance during match play in young football players

Abstract The study examined the effect of caffeine supplementation on match activities and development of fatigue during a football match. In a randomised, double-blind cross-over design, two experimental football games separated by 7 days were organised between the junior teams of two professional football clubs (17.6 ± 1.1 years (±s), 71.7 ± 6.9 kg, 13.9% ± 5.0% body fat). The players ingested either a capsule of 6 mg · kg−1 b.w. caffeine or placebo (dextrose) 65 min prior to the matches. Match activities were assessed using the ZXY match analysis system, and a Yo-Yo intermittent recovery test–level 2 (Yo-Yo IR2) was conducted immediately post-game. Heart rate was monitored throughout the game, and blood samples were obtained at baseline, half-time and after the game. There were no differences between caffeine and placebo regarding total distance covered (10,062 ± 916 vs 9854 ± 901 m), high-intensity running (557 ± 178 vs 642 ± 240 m), sprinting distance (109 ± 58 vs 112 ± 69 m) or acceleration counts (123 ± 31 vs 126 ± 24). In both trials, players displayed lower (P < 0.05) values in total distance and acceleration counts in the last 15 min compared to all other 15-min periods of the matches. Post-game Yo-Yo IR2 performance was not different between game trials (caffeine: 829 ± 322 m; placebo 819 ± 289 m). In conclusion, oral caffeine administration does not appear to have an ergogenic effect in young football players during match play.

Application of the Copenhagen Soccer Test in high-level women players – locomotor activities, physiological response and sprint performance

We evaluated the physiological response, sprint performance and technical ability in various phases of the Copenhagen Soccer Test for Women (CSTw) and investigated whether the locomotor activities of the CSTw were comparable to competitive match-play (CM). Physiological measurements and physical/technical assessments were performed during CSTw for eleven Norwegian high-level women soccer players. The activity pattern during CSTw and CM was monitored using the ZXY tracking system. No differences were observed between CSTw and CM with regards to total distance covered (10093±94 and 9674±191m), high intensity running (1278±67 and 1193±115m) or sprinting (422±55 and 372±46m) (p>.05). During CSTw, average HR was 85±2%HRmax with 35±2% playing time >90%HRmax. Blood lactate increased (p<.05) from 1.4±0.3mM at rest to an average of 4.7±0.5mM during CSTw, with no changes during the test. Blood glucose was 5.4±0.3mM at rest and remained unaltered during CSTw. Sprint performance (2×20m) decreased (p<.05) by 3% during CSTw (8.19±0.06-8.47±0.10s). In conclusion, the locomotor activities during CSTw were comparable to that of high-level competitive match-play. The physiological demands of the CSTw were high, with no changes in heart rate, blood lactate or technical performance during the test, but a lowered sprint performance towards the end of the test.

Effect of short burst activities on sprint and agility performance in 11- to 12-year-old boys.

Abstract Pettersen, SA and Mathisen, GE. Effect of short burst activities on sprint and agility performance in 11- to 12-year-old boys. J Strength Cond Res 26(4): 1033–1038, 2012—There are limited data on how coordinative sprint drills and maximal short burst activities affects childrens sprint and agility performance. The purpose of the present study was to investigate the effect of short burst activities on sprint and agility performance in 11- to 12-year-old boys. A training group (TG) of 14 boys followed a 6-week, 1-hour·week−1, training program consisting of different short burst competitive sprinting activities. Eleven boys of similar age served as controls (control group [CG]). Pre- and posttests assessed 10-m sprint, 20-m sprint, and agility performance. Results revealed significant performance improvement in all tests within TG (p < 0.05), but not between TG and CG in the 10-m sprint test. Furthermore, the relationships between the performances in straight-line sprint and agility showed a significant transfer effect (r = 0.68–0.75, p < 0.001). Findings from the present study indicate that competitive short burst activities executed with maximal effort may produce improvement in sprint and agility performance in 11- to 12-year-old boys.

Anthropometric factors related to sprint and agility performance in young male soccer players

Objective To investigate the relationship between anthropometrics and sprint and agility performance and describe the development of sprint (acceleration) and agility performance in 10- to 16-year-old male soccer players. Methods One hundred and thirty-two participants were divided into three age groups, 10–12 years (mean 10.8±0.50), 13–14 years (mean 13.9±0.50), and 15–16 years (mean 15.5±0.24), with assessment of 20 m sprint with 10 m split time and agility performance related to body height and body mass within groups. Results In the 10- to 12-year-olds, there were no significant correlations between height, weight, and the performance variables, except for body mass, which was correlated to 10–20 m sprint (r=0.30). In the 13- to 14-year-olds, body height was significantly correlated with 10 m sprint (r=0.50) and 20 m sprint (r=0.52), as well as 10–20 m sprint (r=0.50) and agility performance (r=0.28). In the 15- to 16-year-old group, body height was correlated to 20 m (r=0.38) and 10–20 m (r=0.45) sprint. Body mass was significantly correlated to 10 m spring (r=0.35) in the 13- to 14-year-olds, as well as 20 m (r=0.33) and 10–20 m (r=0.35) sprint in the 15- to 16-year-olds. Conclusion Height and body mass were significantly correlated with sprint performance in 13- to 16-year-old male soccer players. However, the 10- to 12-year-olds showed no significant relationship between sprint performance and anthropometrics, except for a small correlation in 10–20 m sprint. This may be attributed to maturation, with large differences in body height and body mass due to different patterns in the growth spurt. The agility performance related to anthropometrics was insignificant apart from a moderate correlation in the 13- to 14-year-olds.

Quantified Soccer Using Positional Data: A Case Study

Performance development in international soccer is undergoing a silent revolution fueled by the rapidly increasing availability of athlete quantification data and advanced analytics. Objective performance data from teams and individual players are increasingly being collected automatically during practices and more recently also in matches after FIFAs 2015 approval of wearables in electronic performance and tracking systems. Some clubs have even started collecting data from players outside of the sport arenas. Further algorithmic analysis of these data might provide vital insights for individual training personalization and injury prevention, and also provide a foundation for evidence-based decisions for team performance improvements. This paper presents our experiences from using a detailed radio-based wearable positioning data system in an elite soccer club. We demonstrate how such a system can detect and find anomalies, trends, and insights vital for individual athletic and soccer team performance development. As an example, during a normal microcycle (6 days) full backs only covered 26% of the sprint distance they covered in the next match. This indicates that practitioners must carefully consider to proximity size and physical work pattern in microcycles to better resemble match performance. We also compare and discuss the accuracy between radio waves and GPS in sampling tracking data. Finally, we present how we are extending the radio-based positional system with a novel soccer analytics annotation system, and a real-time video processing system using a video camera array. This provides a novel toolkit for modern forward-looking soccer coaches that we hope to integrate in future studies.

Accelerations and high intensity running in field and assistant football referees during match play

ABSTRACT Objectives: (1) to examine accelerations and high intensity running (HIR) in football field referees (FR) and assistant referees (AR) during football matches and (2) to evaluate fluctuations in accelerations and HIR between first and second half and in 5-min periods. Methods: All movements of the referees were measured using a radio-based tracking system during 41 matches in the Norwegian top and second league during the 2015 and the 2016 seasons. Movements were classified into accelerations (≥2 m · s–2) and HIR (≥19.8 km · h–1). Results: AR performed 86% more accelerations than FR (158 (147–169) vs. 85 (76–94), P < 0.001, d = 1.9), and FR performed 171% longer HIR distance than AR (619 (534–703) m vs. 228 (208–248), P < 0.001, d = 2.7). When divided into 5-min periods, the number of accelerations (P < 0.001) and acceleration distance (P < 0.001) were reduced towards the end of both halves in AR. However, in the 5-min subsequent to the most intense 5-min period of the match, both FR and AR performed accelerations and HIR (n and m) equal to the 5-min mean (P > 0.35). Conclusions: As the running performance of FR and AR are substantially different, training recommendations for AR should include more accelerations while FR should focus on HIR and endurance training.

The "Football is Medicine" platform-scientific evidence, large-scale implementation of evidence-based concepts and future perspectives

Krustrup, Peter; Williams, C A; Mohr, Magni; Hansen, Peter Riis; Helge, Eva Wulff; Elbe, Anne-Marie; de Sousa, M; Dvorak, J; Junge, A; Hammami, A; Holtermann, Andreas; Larsen, Malte Nejst; Kirkendall, D; Schmidt, Jakob Friis; Andersen, Thomas Rostgaard; Buono, P; Rørth, M; Parnell, D; Ottesen, Laila; Bennike, Søren; Nielsen, Jens Jung; Mendham, A E; Zar, A; Uth, Jacob; Hornstrup, Therese; Brasso, Klaus; Nybo, Lars; Krustrup, Birgitte Rejkjær; Meyer, T; Aagaard, Per; Andersen, J L; Hubball, H; Reddy, P A; Ryom, Knud; Lobelo, F; Barene, S; Helge, Jørn Wulff; Fatouros, I G; Nassis, G P; Xu, J C; Pettersen, S A; Calbet, J A; Seabra, A; Rebelo, A N; Figueiredo, P; Póvoas, S; Castagna, C; Milanovic, Z; Bangsbo, Jens; Randers, Morten B; Brito, J

Position specific player load during match-play in a professional football club

There is a rapid growing body of knowledge regarding physical aspects of a football match due to studies using computer-assisted motion analysis. The present study used time-motion analysis and triaxial-accelerometers to obtain new insights about differences in physical profiles of elite football players across playing-positions. Player performance data in 23 official home matches from a professional football club, during two seasons were collected for analysis. Eighteen players from five different playing positions (central backs: n = 3; full-backs: n = 5; central midfielders: n = 6; wide midfielders: n = 3; and central forwards: n = 4), performing a total of 138 observations. A novel finding was that central backs and central midfielders had significantly lower work-rate in sprints, decelerations and accelerations than full-backs, wide midfielders and central forwards (p<0.001). Furthermore, wide midfielders and full-backs performed significantly more turns (>90°) than central backs. The most common distance covered in high-intensity runs (≥19.8 km·h−1) for central backs, central midfielders, wide midfielders and central forwards was 1–5 m, but for full-backs was 6–10 m. This may help coaches in developing individualized training programs to meet the demands of each position in match-play.