The role of sleep in training optimisation and prevention of injury and illness.

Intense exercise reduces energy levels and breaks down muscle, bone and tendon. As your body recoveries it over-compensates, making you stronger.

If your next session is timed optimally to coincide with the peak of this supercompensation period then in theory you achieve optimal performance improvement. Too late and you miss the maximum benefit. Too soon and your body does not recover fully. If you repeatedly leave to little recovery time you enter the cycle of over-training, injury and illness.

Sleep allows your body to recover more quickly, helping to reduce the necessary recovery time. Given the above propositions, the performance benefits of reducing necessary recovery time are obvious.

What happens when your body gets inadequate sleep?

Research has shown inadequate sleep to be associated with:
• reduced exercise performance
• mood swings
• depression
• decreased immune function
• decreased glycogen production
• decreased protein synthesis
• reduced reaction times
• reduced attention span, alertness and concentration.

Inadequate sleep can not only reduce your performance but also put you at increased risk of overload injuries and illness. Slower reaction times and reduced alertness could even increase risk of traumatic injury e.g. ankle sprain, knee impact injury etc.

How can you ensure adequate sleep? Again, based on research:

• Aim for regular sleep patterns
• Limit alcohol intake
• Limit caffeine, especially in the afternoon and evening
• Avoid drinking too many liquids in the evening - AIS athletes cited night time toilet visits as a common reason for sleep disturbances
• Avoid eating a big meal just before bedtime
• Avoid sources of emissive light, particularly short-wavelength light, before bedtime as they can suppress melatonin, the hormone that controls sleep patterns. That means no TV, computers, phones or tablets before bed.
• If possible avoid high intensity training sessions in the evening.

What if I can’t ensure adequate sleep?

For many people a good 8 hours sleep a night is not realistic for various reasons (stress, insomnia, young children, hectic schedule etc). If this is the case then you need to take this into consideration when planning your training sessions. You may need more recovery time between hard sessions or be more flexible with your training, such as delaying a hard session by a day because you have been up all night with a sick child or had a unavoidable early start.

It's always good to listen to your body, but also think about building in "buffers' that allow you to delay a session even if you are feeling good but know you have done activities that place you at risk.

But most of all, if you aren't sleeping try not worry about it. Any rest is better than none.