Energy Systems and Movement Patterns
The game of hockey at the top level is essentially a low-intensity activity, interspersed with varying bouts of high intensity activity (Lythe and Kilding, 2011). The successful player requires muscular endurance, strength, power, skill, psychomotor attributes and cardiovascular fitness (Reilly & Borrie, 1992).
Hockey has high demands in all three energy systems. The aerobic system is important during prolonged intermittent exercise, and high intensity efforts rely on the anaerobic energy systems, adenosine triphosphate phosphocreatine for the intermediate and anaerobic glycolysis for short term.
The introduction of artificial turf has transitioned the game to be more physiologically demanding (Reilly & Borrie, 1992). With quicker ball movement play accelerates (Malhotra et al., 1983); there are more touches per possession and greater time dribbling, leading to increased skill level and tactical play. The rule changes of unlimited interchange and no off-side, has led to less disruption in play, and greater player movement (Reilly & Borrie, 1992), requiring a greater level of fitness.
High anaerobic power is required for sprint quality and repeatability, and the many explosive activities, like tackling, jumping, turning, hitting the ball, and changing pace. Strength is important in the upper body allowing powerful hitting, shooting and passing of the ball over long distances (Manna et al., 2010). Grip strength is also an important component for stick and ball handling skills (Scott, 1991).
Distance Covered and Playing Positions
Hockey players cover large distances in game situations, from 9.78 ± 0.72 km per player for an international game (Jennings et al., 2012), 8.16 ± 0.43 km per position (Lythe and Kilding, 2011), 7.33 km for Chinese top level layers, and for female players the average was 6.6 km, but up to 9.5 km for some players (Gabbett, 2010). Fullbacks often cover significantly less total distance than all other positions, and running pace during a field-hockey game was 116.6 m/min of play (Lythe and Kilding, et al., 2011).
Papers looking at movement patterns during a game, have found there can be from 90% up to 97.4% of game time engaged in low and moderate intensity activities (MacLeod et al., 2007; Liu et al., 2013; Lythe and Kilding, 2011; Spencer et al, 2004; Gabbett, 2010), with the remaining time spent in high intensity running and sprinting. The range is broad due to the differing speed categorizations based on velocity and techniques used. Positional differences occur for high intensity work, midfielders cover a greater absolute number of sprints and total distance (102 efforts, 648 m), than strikers (92 efforts, 469 m) and defenders (79 efforts, 421 m) (Gabbett, 2010, Jennings et al., 2012). Midfielders and strikers performed more high speed running than defenders and international players performed 42% more high speed running than their national player counterparts (Jennings et al., 2012).
There is large variability in the positional demands of a game, as well as increasing intensities with competition level. This highlights the use of individualised position-specific conditioning throughout a season, and hence the importance of dietary manipulations to match type, intensity and duration of training.
Energy Expenditure, Glycogen Usage and Fatigue
Early pre-turf estimates of energy expenditure (EE) are 30-50 kJ/min and 35 kJ/min, for males and females, respectively (Reilly & Borrie, 1992). More recently on turf, Boyle et al. (1994) found that mean estimated EE averaged 74.2 kJ/min, ranging from 83 kJ/min for the centre midfield to 61.1 kJ/min for the left forward positions. EE during an entire match was 5.19 MJ (Boyle et al. 1994). Dribbling can increase EE by 15-16kJ/min compared to normal running (Reilly and Borrie, 1992).
There is a significant decrease in the amount of high intensity activity performed in the second half of a game, coupled with a significant decrease in average heart rate in the second half (174 ± 12 beats/min vs. 169 ± 11 beats/min), suggesting a manifestation of fatigue resulting in a decrease in performance (MacLeod et al., 2007). To support this second half fatigue, running pace in field hockey decreases by 2.4 to 7.5% between the first and second half of a field hockey game (Jennings et al., 2012; Lythe and Kilding, 2011).
Spencer et al. (2005) analysed movement patterns over three consecutive international games in four days. They found the percentage of time spent standing increased significantly, while the time spent jogging decreased over the three games, with no change in walking or sprinting times. This also indicates a level of fatigue which reduces the ability to perform repeated sprints with limited recovery time.
Based on early estimates for grass play Reilly and Borrie (1992) suggested that muscle glycogen stores in limb muscles would not be depleted at the end of a game. However, more recent data with movement pattern changes and fatigue decrements, there may be depletion in muscle glycogen stores. Maximising carbohydrate recovery between games played on consecutive days is critical to prevent fatigue. Carbohydrate intake may also be important to replenish muscle glycogen preventing second half fatigue during a high intensity single game, and for intense back to back training schedules, or prolonged training sessions >60mins.
References
- Boyle P.M., Mahoney C.A., and Wallace W.F., (1994). The competitive demands of elite male field hockey. Journal of Sports Medicine and Physical Fitness, 34 (3), 235–241.
- Gabbett, T. (2010). GPS analysis of elite women's field hockey training and competition. Journal of Strength and Conditioning Research. Mar, 24(3), 629-38.
- Jennings, D., Cormack, S. J., Coutts, A. J., and Aughey, R. J. (2012). GPS analysis of an international field hockey tournament. International Journal Sports Physiology Performance, 7(3), 224-231.
- Liu, H., Zhao, G., Gomez, M.A., Molinuevo, J.S., Gimenez, J.V., and Kang, H. (2013). Time motion analysis on Chinese male field hockey players. International Journal of Performance Analysis in Sport, 13, 340-352.
- Lythe, J., and Kilding, A. E. (2011). Physical demands and physiological responses during elite field hockey. International Journal of Sports Medicine, 32(7), 523-528.
- MacLeod, H., Bussell, C., and Sunderland, C. (2007). Time-motion analysis of elite women's field hockey, with particular reference to maximum intensity movement patterns. International Journal of Performance Analysis in Sport, 7: 1–12.
- Malhotra, M.S., Joseph, N.T., and Gupta, J.S. (1974). Body composition and endurance capacity of Indian hockey players. Journal of Sports Medicine, 14, 272-277.
- Manna I., Khanna, G. L., and Dhara, P. C. (2010) Effect of Training on Anthropometric, Physiological and Biochemical Variables of Elite Field Hockey Players. International Journal of Sports Science and Engineering, 04 (04), 229-238.
- Reilly, T. and Borrie, A. (1992) Physiology Applied to Field Hockey. Sports Medicine, 14 (1), 10-26.
- Scott P.A. (1991) Morphological characteristics of elite male field hockey players. Journal of Sports Medicine and Physical Fitness, 31 (1), 57-61.
- Spencer, M., Rechichi, C., Lawrence, S., Dawson, B., Bishop, D., and Goodman, C. (2005). Time-motion analysis of elite field hockey during several games in succession: a tournament scenario. Journal of Science and Medicine in Sport, 8(4), 382-391.
Related Pages
- Nutrition for Field Hockey
- Field Hockey fitness testing
- Fitness Components for Field Hockey
- More about anthropometry for hockey
- Hockey Warm-ups
- Another poll about the fitness components for field hockey
- About Testing for Intermittent Sports
- About the sport of Field Hockey