Often I hear the comment from some of my clients that they are so much hungrier on rest days! Why may this be?
First of all let’s look at some of the body systems. There are some actions that require active thought where you are consciously choosing to do something (ex. running) and some that are unconscious (breathing, beating heart, digesting food). These unconscious functions are controlled by the autonomic nervous system.
The autonomic nervous system is subdivided into the sympathetic and parasympathetic nervous system (SNS and PSNS)
The SNS is considered our “fight or flight” system and is activated by any intense physical AND emotional stress.
The PSNS is considered our “rest and digest” system and is activated by calming thoughts and deep breathing.
Activation of the SNS can slow down your digestion. When your body is under stress it will naturally prioritize functions required for survival (increasing blood flow, mobilizing glucose, increasing sweat production) NOT digesting the meal that you may have just eaten or are about to eat.
So now we can look at what your workout day and rest day look like. Maybe on your workout day you get up early, go to the gym for your workout, rush home, eat a quick breakfast, go off to work! Your SNS system is activated and you may not feel as much hunger. Compare that to your rest day where you may sleep in, maybe even not work if it is on a Sunday and have some extra down time. Now your brain can finally “rest and digest” and your hunger response comes on!
Now you know why it may feel like you could “eat the whole house” on your rest days :)