Elite football teams mustn’t sleep on sleep science

IT COULD BE THE DECIDING FACTOR IN WHO WINS THE WORLD CUP IN 2022

FEATURE / DR. CHRIS JAMES (BSC, MSC, DCLINPSY) AND DAVID THORNE (BSC, MSC) SLEEP ATHLETIC

Sleep and performance science is a growing field, with more and more elite performance teams looking to tap into sleep as a way to gain a competitive edge through boosting performance and recovery. Sleep science has been a part of American sport for much longer, with NBA1, MLB2 and NFL3 teams having enjoyed the benefits of specialist sleep guidance for a decade or two. Football has lagged behind, but there are forwardthinking teams that realise that specialist sleep guidance can make a huge difference to athletic performance.

Specialist sleep guidance can have a significant impact on athletic performance in a number of ways

Sleep is vital for all of us. It’s integral for both cognitive and physical recovery and growth. This means sleep also has a massive impact on athletic performance, and this is highlighted within the academic research where simple changes like increasing sleep quantity in athletes (sleep extension) can lead to improved4-7:

• Sprint performance by ≈4% • Jump height by ≈10% • Reaction time by ≈11% • Shot accuracy by ≈15%

This importance is amplified when we look at elite athletes playing within a sport like football, which is so low scoring, meaning marginal gains can have a far bigger impact.

As well as athletic performance, sleep helps reduce athletes’ chances of injury and fatigue, and it improves recovery times. Poor sleep quality increases athletes’ chances of overreaching8 (which is associated with increased injury risk), while sleeping at least 8 hours per night reduces elite athletes’ injury risk by 61%9. This is a significant reduction in risk of injury, yet specialist sleep guidance is still a rarity within football.

We all have a sleep tip…but could this be dangerous?

Sleep science is one of the most frequently spoken about ‘pop science’ topics. We’ve all read or heard something interesting about sleep, and it’s easy to feel like we are all somewhat experts in the field, because it’s something we all do every night. Although there are benefits to some of the basics of sleep science being relatively mainstream, the danger is that it leads to complacency, poor application, and a lot of ‘sleep myths’ based on flimsy or non-existent science.

For example, whilst sleep hygiene (i.e. providing basic education about sleep) can be useful, research shows it is not a very effective way of helping someone with more significant sleep issues (e.g. insomnia symptoms)10. So yes, it’s helpful to know about, but it’s unlikely to help athletes who are really struggling. The other challenge for clubs is adherence and consistency - even if players know what they ought to be

doing to get good sleep, this often doesn’t always happen in practice for a whole range of reasons (e.g. time pressures, distractions, competing demands, fatigue, motivation dips). Furthermore, without routinely screening the sleep health of their players, clubs are likely to be in the dark about which players are struggling with their sleep, when, and in what ways.

Sleep medications (e.g. hypnotics) are prescribed for more significant sleep issues, as medical staff may be unsure how best to support players with sleep issues. However, these medications bring their own issues as they can be highly addictive11 and do not deal with the underlying cause of the sleep problem12, which is typically rooted in behavioural habits, thinking patterns, beliefs, and other psychological factors. Melatonin can be an extremely useful tool in an elite medical team’s arsenal, but only when dosed correctly, given at the correct times, and given to players for the right reasons13 .

Another issue with general sleep guidance is that even if it’s evidence-based it isn’t bespoke. We all have our own unique sleep patterns and vulnerabilities. Brushing all players and staff with the same stroke might have a slight impact, but it won’t tackle deeper individualised sleep issues. Additionally, general sleep guidance is unlikely to be effective if a player is travelling across multiple time zones or they’re particularly vulnerable to travel fatigue and jet lag.

Rarely does one size fit all, so in order to get the best results, we recommend that sleep guidance is tailored to individual players and staff based on their specific sleep patterns, personal vulnerabilities and sleep issues. For the same reason, in our experience teamwide guidance is likely to be more meaningful and useful when based on individual travel patterns and squad-specific sleep problems.

So how does this relate to Qatar 2022?

Qatar offers unique challenges…

Qatar 2022 is the first World Cup to ever be held in the middle of the European league season, with the competition being shifted into the winter to account for the summer heat. This has a significant impact on the fixture congestion seen in club competitions but also means international teams will have less time to prepare for the World Cup. This lack of preparation time makes sleep preparation even more important. During a normal World Cup campaign, players would fly out early to the host or nearby nation to start their training camp, giving players and staff time to adjust to the local time zone and overcome the bad night’s sleep they likely got on the flight over. This World Cup is different.

…And unique opportunities

As Qatar is such a small country, every team has been given their own base camp and the two most distanced stadia are only 55km apart. This means that travel fatigue will be less of an issue in this World Cup than previous tournaments, but it also means there’s more of an opportunity for players and staff to establish a proper sleep routine.

This is where specialist sleep guidance could be highly impactful, offering players an opportunity to develop sleep routines that work for them based on their chronotype, sleep risks and sleep strengths. It also means environmental factors that can impact sleep quality, like black out blinds, bedroom temperature, pillows and noise can be more easily controlled. And finally, it means that players will more easily be able to get out on the training pitch when the sun rises, rather than having to travel, which is a reliable way of speeding up players and staff members’ adjustment to Qatari time.

Some World Cup teams are at greater risk than others

While all jet lag can have a major impact on performance, some teams are at greater risk than others. The most obvious reason for this is that there is a greater time difference between certain countries and Qatar, with research indicating that it takes, on average, a person one full day per hour time difference to overcome jet lag14. Additionally, the direction of travel can also play a role14. Studies have shown that jet lag is more severe when travelling eastward, as opposed to westward14 . This is because our body clocks tend toward slightly more than 24 hours. Research in the field bears this out, with west coast American teams in both American Football and Baseball struggling much more away from home than teams from the east coast of America.

From a performance perspective, this means some countries will benefit from feeling ‘themselves’ within a day or so of arriving in Qatar. Other countries, without utilising specialist sleep coaching guidance, can expect it to take a whole week for them to feel like themselves. By that point, their first match of the tournament will likely already be upon them. The corresponding results of this are numerous:

• Poor information retention, making tactical guidance inefficient15-16 • Inferior recovery, resulting in less intensity in training sessions17 • Potentially greater susceptibility to overreaching, increasing the risk of injury – in fact, athletes getting less than 8 hours of sleep have shown to be at 1.7 times greater risk of injury than those who obtained 8 or more hours of sleep18 . • A greater likelihood of risk taking and worse concentration, leading to more mistakes19-20 • Worse fine motor control and skill execution, meaning players will be performing at percentiles lower than they normally would21

In a tournament where 3 matches are the difference between knockout qualification and an early flight home, there’s no room for a slow start to the tournament because of a controllable factor like jet lag.

So, which teams are at greatest risk?

Well, it’s too simplified to say the countries with the fewest time zones between them and Qatar, like the European teams, have the lowest risk. For example, one of the tournament favourites, Argentina, has a time difference of 6 hours compared to Qatar. If all players were travelling from Argentina, you’d expect them to struggle to have fully recovered from their jet lag before their first fixture of the tournament against Saudi Arabia on 22nd November. The reality is that because the World Cup is in the middle of domestic seasons, players will likely fly straight to the World Cup from their clubs and meet up with their team in Qatar. In their latest squad, Argentina only had 1 player playing outside of Europe - Franco Armani of River Plate (3rd choice GK).

So, instead of there being a European country advantage, there is instead an advantage for countries where the majority of their players play in Europe. What this means is that the strongest teams in the tournament are going to have a significant sleep advantage. The top 10 teams, in terms of odds of winning the tournament, will all have almost entirely Europe-based players: Brazil, France, England, Argentina, Spain, Germany, Portugal, Netherlands, Belgium, and Denmark. In contrast, promising yet ‘underdog’ teams like Mexico (69%), USA (42%), Ecuador (54%), Japan (23%), South Korea (81%), and Canada (46%) will all have to contend with a significantly larger proportion of their squads travelling from regions that will lead to significant jet lag upon arriving in Qatar (percentages are based on the squads for the June 2022 internationals).

What does this mean? Well, it means the underdogs in the tournament are going to be further disadvantaged. These teams should really be utilising sleep health screening for their World Cup squads and identifying which players are likely to struggle the most with jet lag upon arriving in Qatar, which will allow them to adjust their sleep guidance and training load on the back of this. Some managers might even want to take this into account when there’s a 50/50 call on which player to go for in the first game of the tournament.

Figure 1: Petal diagram showing the variety of factors impacting on the sleep quality of elite athletes - Adaptation of diagram taken from Walsh et al. (2021), modified by Barça Innovation Hub

Figure 2: An example of one of Sleep Athletic’s sleep quality radar charts, indicating a player’s sleep strengths and weaknesses across 8 areas of sleep quality.

Family commitments (eg. children, spouse)

NON-SPORT FACTORS

SPORT FACTORS

Social demands/needs (eg. friends, social media)

Individual characteristics (eg. age, gender, disability)

Night competition

(start > 18:00 physiological + cognitive arousal)

Long-haul travel

(circadian rhythm disruption)

Lifestyle choices

(eg. diet, caffeine, leisure)

High training loads

(physiological arousal)

SLEEP DISTURBANCE

Night before competition

(cognitive arousal)

Unfamiliar sleeping patterns

(cognitive arousal)

Early morning training

(start < 8:00 schedule)

Work/study commitments (eg. sponsorship, study or work demands)

Attitudes and beliefs (eg. social influence, individual expectations)

Night Time Symptoms Duration

Timing

Unbroken Sleep Efficiency

Daytime Symptoms

Consistency Satisfaction

And what can performance and medical teams do about sleep risk?

Sleep is one medical area where athletes disproportionately struggle, over and above that experienced by the general population22 . This is why we see reports of sleep medication addiction amongst footballers, which is a worrying trend.

The most important guidance for performance teams is that, although it might feel easier to just give all players the same sleep guidance, players need to be assessed individually when it comes to sleep. Each player will have specific areas of sleep quality that they struggle with and need working on, and areas which are strengths. It’s not just a case of telling players to sleep for 7-9 hours; different players will require different sleep quantities in order to feel refreshed. On top of this, generic sleep guidance does not fit the specific needs of athletes, e.g. elite athletes should actually be getting around 9-11 hours of sleep, as they need more sleep to aid recovery from the physical and cognitive strains they experience23 .

On this same point, not all players will have the same sleep chronotype. You don’t want your players developing sleep debt because you are scheduling training for the morning when many of your key players are night owls and aren’t ready to engage in physically and cognitively demanding training until midafternoon.

The football performance and medicine community can support players getting better sleep by:

• Treat players as individuals with different sleep needs, patterns, and issues

• Prioritise sleep as an area that can have a positive impact across the board for players: motivation, concentration, tactical flexibility, athletic performance, in-game and nutritional decision making. Focus on explaining to players the positive gains they can expect.

• Get a qualified athlete sleep specialist in to provide consultation on how to limit jet lag, tackle sleep issues, and offer guidance on sleep medication. We rightly consult specialists for set pieces, medical issues, mental toughness and nutrition - why aren’t we doing it for sleep too?

• Be cautious in dishing out sleep medication, melatonin and caffeine to players/staff, even if you’re feeling pressured. Follow best practice guidelines, and if you aren’t sure, consult a sleep specialist who can provide advice and suggest effective alternatives to pharmacological interventions.

Conclusion

Qatar is the first World Cup to be played in the middle of the season. On top of dealing with common sleep issues amongst athletes, certain teams are going to have to contend with having less time to recover from jet lag and travel fatigue, leaving their training sessions pre-tournament in Qatar affected and potentially their performance in the first match of the tournament. The positive for teams in the World Cup is that the negative impact on sleep isn’t inevitable. Specialist sleep science can help teams pre-adjust to limit jet lag, tackle sleep issues within individuals, quickly adjust to changes in sleeping environment, improve sleep hygiene through education, and help medical teams avoid medication hangovers and caffeine-induced sleepless nights.

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