Sleep and body composition

The impact of sleep on body composition is indirect.

While there can be associations linked between sleeping more and improved body composition outcomes, this does not mean sleep is the secret to getting lean.

An energy deficit is still the boss.

There could be an argument that sleep itself is beneficial for creating an energy deficit because you are expending energy without any energy intake, but I think that’s starting to move away from the point.

Most of the research indicates the association between increased body weight and sleeping less than six hours per night.

It does not go as far as to say that people who sleep for ten hours per day will be leaner than those who sleep for six.

The next step is to decipher why this might be the case - what changes in the body and mind between getting a good nights sleep and not.

Hormones could be a factor, but they aren’t an area I specialise in or can manipulate, so I won’t go into any detail about the hormonal implications of a lack of sleep beyond saying that.

So instead, let’s focus on the variables that we can control: the 3F’s - food, fluid and fitness.

The key word in that last sentence is control.

When we get tired, our capacity to exercise self-control begins to diminish.

A better way to think about it is there is less of a battery life so self-control when we are tired.

When the battery runs out, we often chase the sugary treat, say no to the hard training session and order in for dinner.

Energy expenditure goes down while energy intake goes up - which doesn’t bode well for body composition.

Tom Fitzgerald