In recent years our understanding of the physical demands of soccer has improved. We
know that the intensity at which the game is played has increased and that the fixture
schedules for professional teams can often be very congested. These factors are likely to
have increased the importance placed on the physical condition of players. Therefore,
the process of monitoring the fitness levels of players is likely to be an important task
within clubs. Any fitness assessments that are employed need to be sensitive enough to
detect changes that may result from different training stimuli. A further critical
consideration for clubs is what are the best practices to implement in order to maximise
recover between matches? The two areas that are central to successful recovery of
performance are the restoration of muscle and liver glycogen stores and the rapid
reduction of muscle soreness.
We have a good understanding of the importance of carbohydrate feeding in the
immediate hours following the completion of exercise, furthermore that high levels of
carbohydrate consumed during short recovery periods can improve subsequent
endurance running capacity in both continuous and intermittent exercise. However,
there is dearth of literature investigating the effects that different types (glycemic index)
of carbohydrates have on subsequent performance of high intensity intermittent
exercise. Furthermore, we know that the movement patterns experienced in soccer
commonly induce symptoms of muscle damage. Despite this there is little research based
information on modalities that reduce these potentially detrimental side-effects
For these reasons the series of investigations that have been conducted in this thesis
were designed with the intent to examine areas that are critical to the preparation and
recovery of soccer players.
The first of five experimental chapters collated information on the use of fitness testing
within English professional football. It was concluded that the practise of fitness testing
players is extremely commonplace and that field-based testing protocols were far more
popular an assessment method. The second experimental chapter went on to
demonstrate that the most commonly used fitness test within professional football (MSFT) was sensitive enough to detect performance changes that occur as a result of
training. A further finding within the context of the question was that it is possible for
female players to significantly improve aerobic capabilities with additional high
intensity aerobic training.
The third experimental chapter investigated the effect different glycemic index high
CHO diets could have on recovery of performance following 90 min of intermittent
soccer type exercise. This study concluded that consuming either predominately high or
low GI CHO mixed meals in the 24h recovery period between bouts of high intensity
prolonged intermittent exercise had no difference on measures of performance.
The final two experimental chapters went on to investigate the effects of cold water
immersion on indices of muscle damage following intermittent exercise. Results from
these investigations suggest that submerging individuals in 10°C water immediately
following high intensity intermittent exercise reduces some but not all indices of muscle
In summary, fitness assessments of players are commonly made within professional
football clubs. The most common test used was the MSFT and this appears to be
sensitive to changes that result as a consequence of training. During recovery from high
intensity intermittent exercise the importance of carbohydrates is apparent although the
type of carbohydrate appears to be less important, furthermore, cold-water immersion
may be effective in reducing some but not all indices of muscle damage.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.