Sporting competitions, even recreational, can be fierce. So the athletes’ training program is always go-go-go. Without proper coaching, monitoring and periodisation in their program, it is very easy to fall prey to over-training and muscle fatigue.
In soccer players aged 16-18 years, lower leg injuries account for 70% of all injuries. With regards to the knee joint, injuries frequently affect the ACL and surrounding ligaments where the incidence rate coincides with the presence of muscle fatigue.
Monitoring fatigue and overtraining
Muscle fatigue has a huge impact on soccer players' performance and can pose a potential risk of injury. Fatigue is defined as a decreased level of maximal power/force in response to contractile activity. Changes within the central nervous system seem to also play a role in the development of chronic fatigue. The first sign of muscle fatigue and overtraining is usually subjectively reported by the athletes themselves. These signs can be:
stress and anxiety
changes in appetite and weight
As muscle fatigue is influenced by multiple factors, it becomes imperative for coaches and trainers to keep a close monitor on players' fatigue levels. One of the ways to help diagnose and ascertain whether athletes are experiencing muscle fatigue is the use of an objective measure like VALD Forcedecks. The Forcedecks is a dual force plate system that detects different parameters of a physical movement and provides numeric data and metrics for fatigue monitoring. We can easily monitor fatigue level through changes in metrics such as:
reactive strength index – RSI (Flight and contact time)
concentric rate of force development – RFD or power
active stiffness (peak active force divided by the change in displacement of center of mass from contact to minimum value).
Fatigue monitoring becomes easier to identify through athlete profiling. This is where athletes' training and performance metrics are measured and analysed periodically. Therefore, any sign of a drop in performance can be picked up quickly and be addressed immediately to prevent the potential risk of injury.
Recovery and prevention of fatigue
For some athletes, they may have a soccer match in the morning and then have to perform again in the final later in the day within just a few hours’ time. Therefore, it is important to be fully recovered as quickly as possible. The aim of recovery is to maximise performance and minimize the potential for injury at the next event. The objectives in the recovery process are:
restoration of function
resolution of muscle soreness
The most important component of prevention is awareness of the problem. Most episodes of fatigue can be mitigated by first identifying the cause, followed by adjustments to training or activity schedules.
In general, fatigue can be reverted by appropriate nutrition (higher fluid and carbohydrate intakes) and adequate rest. Periodisation of training also allows sufficient regeneration time within the training program, and the use of regenerative techniques such as massage, hydrotherapy and relaxation.
These are some of the methods commonly used to hasten the recovery process:
Warm-down or active recovery
5-15 mins of walk-jog regime followed by stretching of the muscles used in training
Deep-water running (hydrotherapy)
Running in the deep end of the pool wearing a buoyancy vest, performed post-strenuous training or match for 3 consecutive days
Cold water immersion (ice bath)
Standing in waist-deep 10-15 degrees water for 5 minutes followed by 1 minute out of the bath, repeated 2-3 times.
Reduce post-exercise delayed onset muscle soreness
Wearing lower limb tights and below-knee socks post-event for the next 24 hours
Avoid post-event alcohol consumption as it impairs muscle glycogen storage vital for recovery
Ensure adequate carbohydrates to fuel the muscle glycogen storage post-training
Replenish fluid and electrolytes lost in sweat by consuming 125-150% of estimated fluid loss (pre and post-event weight loss) in the 4-6 hours after exercise. E.g. Pre-game weight 100kg, post-game weight 98kg, consume up to 2kg x 125% = 2.5L of fluid
Elevated arousal levels correlate to the person’s sympathetic nervous system which controls the “fight or flight” response. This is characterised by adrenaline rush, tachycardia (increased heart rate), increased cardiac output where blood is shunted away from the gastrointestinal tract. This affects the athletes’ recovery as the sympathetic overarousal delay absorption of nutrients from the gastrointestinal tract.
Techniques such as soft tissue therapy, spas, warm baths, showers, flotation tanks, music, visualisation, and relaxation tapes are helpful to keep athletes’ arousal level calm and stable post-training or events.
In the competitive scene, athletes cannot only just focus on getting faster or stronger as this can put them at risk of injuries. Therefore, proper implementation of rest and recovery into their program is super important for any athlete’s longevity in the sporting field.