Not Just a Man's World

I was staying away from home the other week because of work.  For the second week I had a dreadful mattressso my sleep quality was poor and by the end of four days I was stressed and physically tired.

Sleep is a hugely underestimated element of athletic performance.  Dan John swears by it for performance and fat loss.  Robb Wolf is an advocate of sleep and makes the important point that sleep is vital for human survival.  Chris Shugart has even carried out a sleep experiment on himself.

Carl Lanore recently did a Super Human Radio show on sleep (#432) in which he interviewed Dr. Mark Rosekind, whose website includes plenty of resources to learn more, and Paul Becker, inventor of the Earth Pulse machine, which uses pulses of an electromagnetic field to improve the quality of sleep. 

This post is a summary of some of the key things I learned through listening to Dr. Rosekind and doing some extra reading.

Sleep cycles – the basics

There are two types of sleep in the sleep cycle.

• Rapid Eye Movement (REM) –the period when you dream.
• Non-REM (NREM) sleep – divided into four stages, the first two are lighter sleep, the third and fourth are deeper sleep.

Typically we have between three and five sleep cycles in a single night.  But what is a sleep cycle?

1. Start at stage one of NREM, the lightest sleep stage.
2. Move through the stages until sleeping in the deepest stage (four).  As our bodies recover we go less deeply into NREM sleep stages on each cycle.
3. Move back through the stages to stage one (light) sleep.
4. There follows a period of REM sleep before the next cycle of NREM sleep begins.

A good summary of the sleep cycles with an accompanying graph can be found on the Helpguide website.

Benefits of different types of sleep

REM sleep allows our bodies to process thoughts and emotions, retain memories and relieve stress so it is essential to help our minds recover from the day before.  Studies have shown that REM sleep boosts our mood during the day.

Deeper non-REM stages represent the recovery phase for your body when it can mend and heal itself.  These are the stages that are critical for athletic recovery.

What happens if we don’t get enough sleep?

Sleep deprivation occurs if you consistently fail to get sufficient sleep for your body on a daily basis.  Sufficient sleep varies from person to person, but is usually in the range of seven to nine hours.  If you get sufficient sleep then you should be able to get through the day without using aids like an alarm clock or caffeine and you should feel alert all day.

Studies of sleep deprivation have shown that insufficient sleep can reduce performance by 20-50%.  Areas of particular concern to athletes are reductions in:

• reaction times;
• decision making abilities;
• memory and learning; and
• communication skills – particularly important for team sports.

A study carried out on business travellers showed that individuals who were sleep deprived believed that their performance was still optimal (scoring themselves with top marks on a rating scale).  Objective measurement showed that their performance was reduced by 20% on average.  The lesson?  Sleep deprivation affects our judgement as well as our performance.

What other problems might I have if I don’t get enough sleep?

A recent study posted on Conditioning Research concluded that patients suffering from insomnia had reduced orbitalfrontal grey matter (OGM).  Whether the volume of OGM would increase if they resolved the insomnia is unclear.

In a short interview, Neuroscene also discusses the consequences of disrupting our body clocks and circadian rhythms with Dr. Ilia Karatsoreos who talks about current research he is carrying out on sleep cycles.

What can prevent us from sleeping?

Noted inhibitors of quality sleep include:

• consumption of caffeine near bedtime;
• smoking or using other stimulants near bedtime;
• doing exercise not long before going to bed (elevated heart and respiratory rates can prevent you getting to sleep); and crucially
• not allowing yourself enough hours to sleep.

This last one is particularly interesting, since it is probably crucial to today’s society.

Most of us have to get up by a certain time, either to get to work or to do various chores.  Logically we should work backwards from this to ensure that we go to bed early enough the night before, but often we get side-tracked by TV show or the computer and don’t get to bed until it is too late to get a full night of sleep.

How to improve sleep

There are plenty of websites providing advice on ways to improve your sleep.  A few recent ones are:

• Bodybuilding.com – top ten tips to help you sleep better;
• The Happiness Project – fourteen tips for getting more sleep;
• Dr John Briffa – Natural strategies for individuals who have difficulty falling asleep at night and getting up in the morning

The key points can be summed up as:

• develop some pre-bedtime habits to cue your body that it is time to sleep;
• avoid exercise and TV before going to bed (allow about an hour if possible);
• learn a physical relaxation skill (eg. stretching) that can be a pre-bedtime cue and can also be used if you wake up during the night;
• avoid alcohol and caffeine before going to bed;
• sleep in a completely dark room (bin the LED clock);
• avoid having items in the room that may make noises (eg. mobile phones);
• sleep in a cool room,
• allow yourself time for a full night of sleep.

This has really hit home to me that we should all be caring about the amount and quality of the sleep that we get.  Do you manage to get enough sleep to maximise your recovery?

Related posts:

1. Lessons learned: summer sleep cycles
2. Blog-watch: latest sleep round-up
3. Impact of artificial light on sleep
4. Lessons learned: exercise and the menstrual cycle