Fatigue in Soccer

From a general perspective, fatigue can be defined as “an acute impairment of performance that includes both an increase in the perceived effort to exert a desired force or power and/or any reduction in the ability to exert maximal muscle force or power” (Gandevia, 2001). For a clearer definition in relation to the game of soccer, fatigue “is generally referred to as an inability to maintain physical and technical performance during a match” (Jan Van Winkel, Kenny McMillan, Paul Bradley, David Tenney, and Werner Helson, 2014). In essence, a coach’s training organization strategy must seek to progressively improve the team’s fitness levels in order to delay the onset of fatigue, which is detrimental to performance.

When discussing the concept of fatigue, there are two sub-classifications including central and peripheral fatigue. The classification can be “central when the origin is proximal and / or peripheral when the origin is distal to the neuromuscular junction (Gandevia, 2001). Ermanno Rampinini, Andrea Bosio, and Ivan Ferraresi (2011) reported that central fatigue appears to be the main cause of the reduction in maximal muscular contractions and sprint ability while peripheral fatigue is more related to muscle soreness, which can be linked to muscle damage and inflammation. The idea is that due to the complexity of fatigue, coaches must be consciously aware of the need for players to recover psychologically and physiologically in order to maintain health and performance.

There are many possible metabolic factors that can lead to peripheral fatigue including the reduction of adenosine triphosphate (ATP) and creatine phosphate (CP), a depletion of muscle glycogen, and drops in pH due to muscle acidosis (Jan Van Winckel et. al., 2014). With regards to muscle glycogen depletion, a study by Krustrup et. al. (2006) concluded that low muscle glycogen levels within the individual muscle fibers were directly related to the hindrance of sprinting at the end of the game (Jan Van Winckel et. al., 2014). In addition, as hydrogen ions are produced due to anaerobic glycolysis (from intense bouts of exercise), the acidity within the cell increases (Jan Van Winckel et. al., 2014). Thus reducing the pH value below neutrality (7.4), and possibly causing a fatigued state.

When analyzing fatigue from a reductionist standpoint, managing fatigue appears to be as simple as developing a strong aerobic base to increase recovery capabilities in addition to maintaining proper hydration and nutrition protocols. However, if fatigue is considered as a complex system, an understanding of fatigue as a “sensory perception, rather than a physical phenomenon” can be had (E V Lambert, A St Clair Gibson, and T D Noakes, 2005). From an integrative perspective, the brain organizes the metabolic (physiological) changes occurring during exercise in order to decide whether or not to increase, maintain, or decrease the intensity of work. Ultimately acting as a protective mechanism (Don Kirkendall, 2012). Moreover, central fatigue is governed by “how each athlete’s brain interprets the signals delivered and integrated. This milieu is entirely individual – a personal illusion. Athletes that consistently win are those whose illusions interfere the least with performance. And they can’t be expected to deal with those illusions if they haven’t experienced them and that comes from training” (Kirkendall, 2012).

Coaches can increase their team’s buffering zone between performance and fatigue by creating a training environment that prepares the team for the demands of the game. However, one of the main contributors to fatigue in soccer players is due to insufficient training session planning. Kirkendall (2012) said, “Finally, there is the problem with too much training and insufficient rest. Some coaches and athletes seem to forget that training is the stimulus and that cellular adaptation occurs during rest between bouts.”

One sufficient training organization strategy is Tactical Periodization, which revolves around operationalizing the coach’s game model through weekly microcycles that aim to “avoid a large amount of the same physical fitness component stressed the day before, giving the body time to recover. Recovery would take place, at least partly, by switching the dominant physical fitness component throughout the week” (Juan Luis Delgado-Bordonau and Alberto Mendez-Villanueva, 2012). Xaiver Tamarit (2012) continued by stating, “Tactical Periodization has the virtue of increasing a player’s capacity to concentrate through training, also, the creation of habits enabled by this process allows for acquired knowledge to become part of the subconscious, reducing the use of the central nervous system”.

Soccer matches are extremely intense, and the ever-changing situations can raise stress levels amongst the players if they are unsure of how to solve the difficulties on the pitch in a unified way, thus increasing central fatigue. In Tamarit (2014), Vitor Frade said, “Central nervous fatigue is one of the problems in collective sports. Fatigue is characterized by the inability to concentrate and to save effort resulting in a loss of understanding of the game.” The idea is that if the coach appropriately implements and trains their game model with clear principles and sub-principles, the team will be able to interpret and read the game in the same language, reducing stress and subsequently, central fatigue.

By implementing clear playing principles and respecting the training-recovery continuum, coaches can delay the onset of fatigue in their players, and ultimately provide them with the greatest chance of experiencing success on the field.

References:

Bradley, P., Tenney, D., & Helsen, W. (2014). Fatigue. In J. V. Winckel (Author) & K. McMillian (Ed.), Fitness in Soccer: The Science and Practical Application. Klein-Gelmen: Moveo Ergo Sum.

Delgado-Bordonau, J. L., & Mendez-Villanueva, A. (2012). TACTICAL PERIODIZATION: MOURINHO'S BEST-KEPT SECRET?. Soccer Journal, 57(3), 29-34.

Gandevia, S.C., 2001. Spinal and supraspinal factors in human muscle fatigue. Physiol Rev, 81 (4), pp. 1725-89.

Kirkendall, D. (2012). Fighting Fatigue: Understanding and Managing Soccer Fatigue. Performance Conditioning Soccer, 17(3), 1-3.

Krustrup, P., Mohr, M., Steensberg, A., Bencke, J., Kjær, M., & Bangsbo, J. (2006). Muscle and blood metabolites during a soccer game: implications for sprint performance. Medicine & Science In Sports & Exercise, 38(6), 1165-1174 10p.

Lambert, E. V., Gibson, A. C., & Noakes, T. D. (2005). Complex systems model of fatigue: integrative homoeostatic control of peripheral physiological systems during exercise in humans. British Journal Of Sports Medicine, 39(1), 52-62.

Rampinini, E., Bosio, A., Ferraresi, I., Petruolo, A., Morelli, A., & Sassi, A. (n.d). Match-Related Fatigue in Soccer Players. Medicine And Science In Sports And Exercise, 43(11), 2161-2170.

Tamarit, X. (2014). What is Tactical Periodization? Bennion Kearny Limited.