Mammoth’s resident sleep expert, Dr Jonathan Bloomfield, shares why sport is now paying close attention to the benefits of sleep.
I’ve always said that every individual would do well to pay closer attention to their sleep habits. I’m a big advocate of using the power of sleep to optimise everyday health. From energy levels to the immune system to mental wellbeing, sleep is proven to be a powerful tool in keeping us happy and functional. Throughout our lives we all share the same common truth: we have one body and mind, so we have to look after them as best we can.
In recent years, however, it seems as though the world of elite sport has truly switched on to the importance of sleep and recovery. Of course, athletes from all sports must rely on their bodies to earn them a living. With that in mind, it’s no surprise that the means by which they compete and often make a living needs close attention. So, in this article I want to focus on the high performance athlete: if you are one or aspire to be one, I hope there’s some interesting information in here for you.
Understanding fatigue and recovery
There are many factors that contribute to fatigue: there are mental, physical, social and emotional elements to consider. Over time, we all accumulate fatigue when we don’t allow enough time to recharge and enjoy some down time. Ultimately, the accumulation of fatigue can begin to impact on our wellbeing – reducing concentration, coordination, energy levels and physical capacity for work. For athletes this is a significant issue because it can limit performance ahead of a competition.
It is the role of scientists like myself to measure and influence the fatigue–recovery balance. Over the course of my career I have worked with many professional teams, elite sportspeople and Olympians to help them understand what they need to do to achieve performance gains and reduce risks. These risks can include illness, injury, burn-out or simply lack of concentration. Just as a nutritionist will work with sports stars to help them refuel with the right balance of protein, carbohydrate, fats, vitamins and minerals, so I look at fatigue and an athlete’s state of readiness.
Fatigue specialists like myself have developed systems of monitoring “workload”. We measure how much (volume), how hard (intensity) and how often (frequency) “work” can be undertaken before health suffers. We often talk about getting our athletes into a state of “readiness” – a state where they have achieved a state of wellbeing that will allow them to begin their next phase of “work”. If an athlete is not ready for work – perhaps a match or tough training session – then we say that they are in a “state of compromise” that may lead to underperformance or injury. At times, it can be a very fine line.
In English football’s Premier League or the rugby Premiership, the discussions around burnout and performance dips is particularly topical. Many elite players now find themselves training and playing for 10 or even 11 months of the year without a break. The cumulative effect of this can be devastating physically, but often it is fatigue that is a precursor to a dip in form or, worse, an injury.
How often have you seen a football player’s performance begin to drop midway through a season only to improve after a couple of games off. Squad rotation and managing workload is now an essential part of professional sport. And you might be surprised to see how much work goes on behind the scenes to monitor data, assess player fitness and, most importantly, safeguard against burnout.
When it comes to recovery, you may already have heard stories of some unusual and bizarre practices to help sports stars feel refreshed and energised. Take Mo Farah’s oxygen tent, which he used before London 2012; Andy Murray’s ice baths at Wimbledon; and Michael Phelps’s cupping at the Rio Olympics. While these strange habits often grab the headlines, nutrition, hydration and sleep are still recognised to be the most powerful methods of recovery.
Much of this can be attributed to the rise in professional staff and trends of sophisticated monitoring procedures at professional clubs. As money has flooded into sport and the world has become more commercially minded, the culture within teams and organisations has visibly changed. As the bar has been raised, the margins between winning and losing have become finer.
Lifestyles have changed to achieve success and it is no longer acceptable to indulge in smoking, alcohol or a poor diet. Similarly, failing to pay attention to sleep is a no-no. Entire teams of support staff are now employed to implement changes to exercise and recovery plans. Many of these recommendations are informed by detailed research, such as the landmark studies that have illustrated how quality sleep can benefit athletes.
A number of research studies have been performed by Stanford University within their athletic population to show that “extended” sleep length plays a significant role in athletic performance. Allowing student athletes to reach up to 10 hours of sleep over a period of 7 weeks produced significant performance improvements across several different sports including:
- 8% improvements in 15m speed
- 20% improvement in reaction time off the block
- 10% turn time efficiency
- 19% increase in kick-strokes
Collegiate Basketball Players
- 9% improvements in free throw shooting accuracy
- 9.2% improvement in 3 point shooting accuracy
- 0.7 sec faster sprint time over 95yards
- Overall improved mood and wellbeing scores
Collegiate Tennis Players
- 1.5 sec faster at tennis sprint drill
- Significant improvement in serving accuracy
- 42% improvement in hitting depth drill
- Overall improved mood and wellbeing scores
What happens while we sleep?
It’s important to note that while science is taking great steps forward in understanding the process of sleep and the effects of sleep on the body, our knowledge of the night-time hours is still in its infancy. However, there are strong indications that a number of processes take place while we sleep. Physical and mental repair is thought to take place at night as the hormone surges of the day, such as adrenaline and testosterone, die down and the body rebalances cortisol levels to regulate stress.
Once asleep, the body also typically sees a spike in growth hormone production, which is directed to areas of the body where it is needed most. This contributes to the development of our muscles and bones, and the regulation of our metabolism. We also get an increase in the hormone prolactin, which helps to reduce any inflammation.
During sleep the breathing rate slows and deepens, delivering more oxygen to the bloodstream than when awake and at rest. Our brains and central nervous systems develop to recognise, restore and refine the motor skills we have learnt, as well as the context of when to apply them through experiential learning. To put it a different way, all the things an athlete learns during coaching sessions, competitive matches and analysis meetings is consolidated at night. These skills eventually develop to the point of automation and instinct when athletes are World Class.
Something worth noting is that problems only arise when athletes consistently lose sleep. Athletes can often experience a single bad night of sleep, particularly before a big event, but this short-term loss does not seem to have a major impact on how they will be able to compete the following day. What’s more concerning is when sleep loss is more regular to creates an imbalance in the autonomic nervous system, which controls our body’s essential functions.
How does this present itself?
Brain function and cognitive abilities are often the first thing to suffer, as decision making skills, judgement of distance and speed and reaction time begin to fail. There has also been some evidence produced that shows perceptions worsen around feelings of pain, depression, tension, confusion, fatigue, anger and vigour (which negatively affects mood, motivation and competitiveness) and there is also a higher susceptibility to gain illness due to workloads and immune suppression.
There may be several factors why top athletes (and coaches!) may experience continual sleep loss based on situational, medical and behavioural factors including:
- Scheduling and types of training (e.g. early morning weights)
- Scheduling of competition and congested fixtures (e.g. afternoon/evening kick off)
- Scheduling of travel
- Poor sleep habits and hygiene (e.g. over-arousal)
- Irregular sleep/wake & nap timings,
- Hotel beds & unfamiliar surroundings
- Post-match media and corporate responsibilities
- Light exposure (natural and artificial)
- Jet lag (plus connecting with loved ones at home on a different time zone)
- Chronotype (night owls vs intermediates vs larks)
- Over hydrating leading to increased bathroom visits
- Pain and injury
- Overuse and or ill-timing of caffeine
- Stress, anxiety, depression
- Studying for exams
- Medical sleep disorders (e.g. Insomnia, RLS, Apnea)