Military tackles sleep secrets
What can a Defence Force sleep study tell us about how to think and perform better - and what are the tricks to getting 40 winks? Eugene Bingham reports.
There’s a confronting question Captain Dave Edgar asks audiences, both civilian and military, about their night-time activities.
‘‘ Right,’’ he’ll ask the room, ‘‘who sleeps poorly here, or who would like to enhance their sleep?’’
Inevitably, he says, 95 per cent of people will put their hands up.
And then he’ll say: ‘‘What if I said there’s a device that you could wear that would give you graphs about the quality of your sleep, the quantity of your sleep, give you tips on how to sleep better . . . but it’s going to cost you around $600 to $800. Who would be prepared to buy it?’’
There will be murmurings, but, eventually, nearly all the hands go up.
‘‘ OK,’’ he then says, ‘‘ well, I could tell you a way that’s free, and there’s literature that shows it will work.’’
The clamouring for the answer will be deafening. ‘‘What is it? Tell us.’’
Edgar: ‘‘ Don’t after lunchtime.’’
Usually, he says, sniggers will ripple through the room. They already know it’s true, but, still, many of them will drink caffeine in the afternoon and evenings.
And that’s the problem with sleep. We all know how important it is, how bad we feel when we don’t get enough sleep, but we’re all striving for answers we can only dream of.
Edgar – who hasn’t drunk coffee after lunchtime for three years – knows all about the importance of sleep. He’s in a small unit of the New Zealand Defence Force called the performance health team, and for the past few years, he’s been studying sleep.
It’s part of work he’s doing on his PhD through Waikato University, looking at enhanced physical performance and recovery within Defence. Part of that means understanding how recovery and sleep can make people perform better, something that can sometimes be hard to explain.
‘‘The mindset is changing but you’ve got some regimental people in there who say, ‘What do you do?’ And I’ll say, ‘I’m a scientist.’ And they’ll say, ‘Oh, are you just trying to make it easier’?’’
The answer, of course, is no. ‘‘ We’re trying to be smarter,’’ says Edgar.
Part of his work has involved looking at sleep during Defence courses for recruits.
‘‘One of the first things we’ve seen in the research I’ve done is that the amount of sleep in drink coffee
Defence within these courses has been on the low side of what’s acceptable for good restorativestate sleep, and getting on the verge of sleep deprivation.’’
And it’s not just about the quantity of sleep – it’s the quality, he says.
During a good, deep sleep, the body regenerates cells, and the brain consolidates and refreshes for the day ahead.
If you don’t get enough good sleep, says Edgar, you whittle away your cognitive function. This is stuff we all know, right? When you’re tired, you don’t make good decisions, you can’t think straight, you forget things.
In the military, he says, yes, you need to be physically fit, ‘‘but we also have to be able to think clearly on our feet’’. And the stakes can be high.
He equates it with rugby. The higher up you go – all the way to the All Blacks – the ability to make snap decisions, almost innate thinking, becomes more important. And if the thinking is clouded because players are tired, things can go wrong.
‘‘ But at the end of the day, if that pass goes wrong or the ball gets dropped, they carry on. Whereas in Defence, it can be lifethreatening.’’
Edgar is almost uniquely qualified to use rugby and Defence analogies. After joining the Army as a 22- year- old, he served as a soldier working in catering for several years.
But he always had an interest in high-performance sport – Edgar started running at 5 yearsold, has represented New Zealand in triathlon, and is still a competitive long-distance swimmer, currently in training to swim the Cook Strait and harbouring ambitions to swim the length of the Waikato River.
And, so, eventually, he wanted to develop his understanding of exercise and how the body works.
He left the Army to study physical education at Otago University, and went on to work as a strength and conditioning coach for Super
Rugby teams and internationally with Samoa. He worked in Japan for a club team for several years, until the Edgar family wanted to come home.
During his time with the Chiefs, Edgar had gained selection as an officer in the Army Reserves. On his return to New Zealand, he decided he wanted to go back to military life fulltime, to see if he could bring some of his knowledge to the forces.
‘‘So, I’ve got this history with Defence, I’ve done basic training, I’ve done officer training, but I would still call myself a strength and conditioning coach.’’
From his base in Marlborough, Edgar and his boss, Major Jacques Rousseau, look for ways to improve performance amongst military personnel.
They work across the Army,
Navy and Air Force, including with specialised units such as the SAS and Navy dive squad. Last year, Edgar carried out an observational study on trainee officers, seeing how sleep affects physical performance.
It was the Joint Officer Induction Course, a six-week training programme across the services.
The 22 participants were fitted with a wrist-worn actigraphy device to measure activity, rest and sleep for the duration of the course. They carried out a series of physical tests – a 2.4km run, pressups, and curl- ups – before, during and after the course, as well as answering questions about how they felt: their mood, stress, fatigue and soreness. Using a midpoint of 6 hours 15 minutes of sleep a night, Edgar tracked who was sleeping more and less than that. Even though it is less than the recommended 7-9 hours for adults, could small differences in sleep be critical? ‘‘We were looking at whether those who slept a little bit more performed better.’’
And the results, presented to the Sport and Exercise Science Conference last month, showed that, yes, even just a bit more sleep counted.
‘‘Those that slept on average about 36 minutes more per night did show better gains in aerobic fitness on the 2.4km run and had small benefits to upper body muscular endurance.’’
And in those subjective measures, too, there was a difference.
‘‘An interesting finding was that those that slept more would report sometimes they were still sore, and they could still be a little bit fatigued, but their mood and stress was significantly better. ‘‘That correlates to them poss
ibly adapting because they’re managing to push themselves quite hard in the training – they’re thinking, ‘Actually I can handle this’.’’
With data showing that, yes, sleep delivers improvements, Edgar has been trying to see if there are differences that can be made on the courses.
While military life traditionally begins early, he’s asking, does it have to be so early?
Normally recruits are up at 5.15am, straight into a rigorous routine of exercises.
‘‘Whereas that’s one of the things we shaped over the time of this course: try to put that wakeup time a bit later. Could it be 5.45? Even an extra 20 minutes or something?’’
Another area Edgar is looking at is lighting in the barracks. Does dimmer lighting in the evenings make a difference to quality of sleep?
As someone who studies sleep, Edgar takes bedtime seriously. And lighting is one of the things he has changed about his bedtime routine.
In the evenings, he and his wife dim the lights a few hours before bedtime: it’s all about training the brain to start thinking about sleep.
Edgar believes it’s important to get into a routine. When he talks to people, they often have a routine in the morning – get up, have breakfast, have a shower, for example.
‘‘ But with sleep it’s like, ‘ Right, I’m going to bed’, from whatever they’re doing.’’
Edgar tries to prepare for sleep, getting off his laptop and devices early in the evening, and going to bed at the same time.
‘‘Another thing we do is have no artificial light in the way of alarm clocks with flashing lights or TVs or anything in the bedroom. And we don’t heat our bedroom either because you sleep better in a cooler environment.’’
And don’t forget that other big thing, the simple, cost-free sleephack: ‘‘Watch your caffeine intake.’’
‘‘If the ball gets dropped, they [the All Blacks] carry on. Whereas in Defence, it can be lifethreatening.’’