Have you ever wondered how much fatigue affects your football (or soccer for our US friends) skills in the second half of a game? A recent study by Russell et al (1) at Swansea University examined the effects of exercise-induced fatigue on skills performed throughout match play.
Fifteen academy players had their passing, dribbling and shooting skills examined during a soccer match simulation (SMS). Precision, success rate, and ball speed were all recorded via video analysis, whilst blood samples were taken pre-exercise and every 15 minutes during the simulation as well as 10 minutes in to half time.
Test-retest repeatability was confirmed through preliminary testing. Shooting accuracy and passing speed were both noticeably affected by fatigue with shots taken after exercise being 25.5 ± 4.0% less accurate than those taken before exercise and passes in the last 15 min being 7.8 ± 4.3% slower than in the first 15 min. Passing and shooting speeds were also slower during the second half of the simulation when compared with the first half (shooting: 17.3 ± 0.3 m·s-1 vs 16.6 ± 0.3 m·s-1, P = 0.012; passing: 13.0 ± 0.5 m·s-1 vs 12.2 ± 0.5 m·s-1, P = 0.039). Surprisingly, given the results for the shooting and passing measures, dribbling performance was unaffected throughout the simulation.
These findings demonstrate that soccer-specific exercise influenced the quality of performance in gross motor skills, such as passing and shooting. Whilst we could all have likely predicted the inverse relationship between fatigue and performance levels, the extent to which performance was affected is rather interesting. Of particular interest, is that fatigue affected shot accuracy by a huge amount (roughly 25%). With football being a relatively low scoring game, shot accuracy is of the highest importance. There have been clubs who have been relegated (costing them around £50 million) where it could all have been so different had a shot which was taken late in the game, crept in to the top corner rather than hitting the post and rebounding away.
The results emphasise the importance of substitutions in football. They say many managers “sink or swim” by their substitutions and this may give a little inkling as to why. Of course, the tactical benefits of mixing things up by bringing in new personnel are obvious, however this study suggests it is imperative for a manager to be able to identify a player who is particularly fatigued and determine the correct timing to call upon a replacement.With shooting performance appearing to be most susceptible to deterioration in performance, substitutions in the forward positions may be more important still. Here’s hoping Harry Redknapp can do a better job of this in the summer than Steve McLaren did previously.
Beyond substitutions and as the authors suggest, interventions to maintain skilled performance during the second half of play are warranted as a result of this study. For those of us who have to play 90 minutes, what strategies can we adopt to delay fatigue and ensure optimal performance for longer?
- Ensure adequate fluid/electrolyte provision through sports drinks.
- Introduce carbohydrate supplementation to replenish depleted glycogen stores.
- Introduce aerobic training
- Aim to buffer lactic acid. Sodium bicarbonate (good old fashioned baking soda) would be one option, however some users may suffer gastrointestinal distress from this method so it would definitely doing a dummy run before trying this in a match for the first time. Williams (2) suggests the following procedure, repeated several times, to determine if bicarbonate supplementation is appropriate for you:
- 2 days light training
- Perform a time trial
- 2 days light training
- Repeat the time trial in a similar environment after bicarbonate supplementation
Ingest 0.3 g of sodium bicarbonate per kg body weight approximately one to two hours before the time trial. eg. for a 85kg football, consume 25.5 g of sodium bicarbonate.
- Alternatively, you could try a beta alanine supplement such as iForce beta-alanine or IntraXcell by Athletic Edge Nutrition. Studies suggest a recommended dose of 3.2 – 6.4g/day. Check out our beta-alanine article for more information.
- Glycocarn (GPLC) and citrulline malate are two other promising lactic acid buffers that could be beneficial in this situation.
- Finally, aim to stay adequately hydrated. Dehydration will negatively impact your performance for a whole host of reasons. Take a look at our Six Reasons to Stay Hydrated article for more information on this.
Whilst the study does suggest that there fatigue can impair football performance, football is such a multi-faceted game that one cannot base conclusions simply from the results of this single study. With so many psychological and physiological factors involved, future research in the area and perhaps some position-specific studies would certainly help shed more light on this topic.
Author: Hassan Muzaffar
1. Russell M, Benton D, Kingsley M. (2011) The effects of fatigue on soccer skills performed during a soccer match simulation. International Journal of Sports Physiology and Performance, 6 (2). P.221-233
2. WILLIAMS, A. (1996) Research suggests it may boost performance in short events, but it can have nauseating side effects. Peak Performance, 73, p. 6-7
© 2012, Hassan Muzaffar. All rights reserved.