Rest days are critical for anyone in the pursuit of better health, performance, and or body composition. Rest days help give your body the time it needs to repair and replenish many various areas and functions of our body: muscles, nervous systems, glycogen stores, connective tissue, joints, and more.
Have you ever noticed that there are *mandatory* scheduled 1–2-minute rests in between lifts in your programming or class workout? Similar principles apply to our nutrition approach and training/workout regimen. Keep reading to learn what we mean by this.
The Science
Some things do and do not take conscious thought for your body. You don’t have to think about your heart beating or your kidneys filtering through fluid, etc. (Autonomic Nervous System, ANS.) But your body DOES have to actively think about firing the muscles needed while working out and voluntarily choosing to move in specific patterns (Somatic Nervous System. )
The ANS can be further divided into the sympathetic and parasympathetic nervous systems, PSNS.
The SNS, coined the “fight or flight” system, is used to “protect” us from perceived danger and often prepares the body for that danger. This system would be fired off if you’re running from a bear, BUT this system is also activated by other stressors (like intense physical exercise or emotional stress.)
The PSNS is almost the opposite of the SNS, as it is called the “rest and digest” system. The PSNS lowers the heart rate, increases activity in digestive mechanisms, and more. This system can be activated by deep breathing, spending time in nature, and using calming words or thoughts.
When the body thinks it is stressed and has to run out of a burning building, its top priority is NOT to digest your food… It wants to get the hell out of the building!! If we apply this same principle to training with intensity, the body is worried about actions necessary to survive. Some of these resulting actions can be increased blood flow throughout the body’s muscular structure, bringing glucose quickly into the bloodstream, increasing sweat production, and more.
The body is not as concerned with hunger compared to some of these other functions, which can lead to suppression of appetite and decreased hunger.
What’s on YOUR plate? (*not just food*)
Even if you are not training as often as an elite athlete but still train somewhat frequently (like an hour CF class several times a week), you could still experience a decreased hunger response.
Why? We have to consider what other stressors may be in your life: job, children, emotional stressors, etc.
In a recent Instagram post, we laid out this common example: “ You start the day with a HIIT session, rush home to shower as fast as you can, then rush to work. From there, you’re bombarded by your job all day. Now compare that to your Sunday rest day. No gym or job to rush to, no “bear attack” of a workout. Your brain is FINALLY in “rest and digest” mode, and your hunger response comes online in a BIG way.”
Rest days give our body the chance and time to transition out of a chronic “fight or flight” mode (activated CNS) and transition more into the “rest and digest” mode.
“I’m not burning as many calories, so I don’t need to eat that much…”
For some, it can be tempting to eat significantly less on a rest day because intentional movement via exercise/training decreases. This can partially be accounted for from years of misinformation and marketing from the media and societal influences spreading the widespread belief that you need time in the gym to burn calories. Which *YES* calories are burned during exercise; they are not your body’s only source of energy expenditure. On average, about 50% of the calories burned come from our Basal Metabolic Rate (BMR.)
This concept is highlighted further in another blog post, but the calories burned from our exercise have much less impact than we may think. But we also have to remember that working out ONLY to burn calories should not be the only reason we are working out.
*This may prompt some further internal questions, and if this is occurring, reach out to your coach/us. We would love to help you, and in some cases, that might mean us guiding you to someone qualified in mental health if needed.
The catch-all problem is if we *are not* taking appropriate rest days and or lowering our food intake on those days. The CNS cannot prioritize proper recovery, muscle tissue does not get the chance to repair optimally, and our glycogen stores are not refilled. This cycle can lead to potential problems like reduced energy (mentally and physically), comprised recovery, impaired performance in the gym, higher potential for injury, and non-ideal body composition effects as your body attempts to cope with these constant stressors.
To tie it back into our lifting analogy from earlier, yes, you could say screw it and try to hit another lift immediately after you finished a lift when the programming has it written to rest two minutes in between in the lifts intentionally. There is potential that you could successfully hit the lift. Still, likely, your body was not able to “recover” and perform optimally with the 10 seconds of rest versus its potential after two full minutes of rest.
But exercise is my stress relief?!
I get it. When you are at the gym, you often can see friends, connect with your community, listen to loud music, and not think about other responsibilities: work, getting your kid to sports, having to take your car into the shop (You get the point.) Sometimes, it can be the best part of our day to go to the gym and the planned time to “de-stress.” While many of us are very passionate about our fitness and health pursuits, it can be easy to forget that biologically, training is a stressor on the body.
Whenever the body is stressed, it cannot differentiate everyday stressors (like taking care of the kids, work, etc.) from our stressors of exercise. It just knows that it is stressed out and responds in a “fight or flight” manner. This response is led by our sympathetic nervous system (SNS) and recruits the adrenal glands to release epinephrine and cortisol (high cortisol levels are linked to higher stress levels.)
Food can allow our body to lower the stress response and elevated cortisol levels (especially carbs). Our bodies can then transition from an elevated “fight or flight” mode and shift back towards a regulated level with the Parasympathetic Nervous System (“rest and digest.”). It is also important to note that proper recovery and fuel can help you perform even better in the gym the next day.
In our go-go-go society and culture, it is very challenging to take a step away, but even the Energizer BunnyTM needs refueling at SOME point to keep chugging along. Plus, it probably goes faster after getting new batteries than when it is running out of juice. It also cannot continue to go ANY further after it has entirely run out of fuel. Our bodies can almost act in the same manner, but with our fuel being food and not batteries.
So, what can I do?
There is hope! Some general recommendations may potentially lead to more regulated hunger levels on training -vs.- non-training days. Some ideas could be making sure you are eating enough on your training days AND rest days, potentially increasing overall macro intake across the board, reducing the toll of emotional stressors, etc.
While we aren’t asking you to change your job as a noticeable stress reduction, you can look into journaling, intentional breathing practices, or mediation as a way to shift more into the “rest and digest” mode on training days as well. Even if that means you do not turn on the radio/speaker in your car for 3 minutes and work on deep breathing instead- it is a start!
Specific recommendations vary based on the individual, and the root cause of increased hunger could go beyond just rest day nutrition. If you feel these are issues for yourself, let us help you to piece the puzzle together!