“How is it possible that I’m just as hungry as on a training day?”, a question that I hear quite often from athletes when they come to see me. There is a strong belief that we don’t need a lot of energy when we don’t exercise. Of course, energy expenditure is reduced on a rest day but our body still needs a lot of energy to recover; and it needs energy to function. Even without exercise our body needs between 1300-2500 kcal/d. Some well trained guys with a lot of muscle mass may need even more than that. After strenuous exercise our body needs to rebuild and replenish its stores. Looking at various metabolic processes, you’ll notice that they require up to 24 hrs and more, especially after hard efforts. Recovery isn’t over after a recovery shake, recovery only starts with a recovery shake.

Cell types within skeletal muscle that contribute to muscle-immune cell interactions and regulate muscle adaptation following exercise (Peake et al. 2017)

Your Training Day influences Your Rest Day Hunger

Athletes often underestimate the time it takes to fully recover after a hard effort. Just because you don’t feel sore doesn’t mean you’re fully recovered (see figure above). An intense training session causes a lot of stress on our body. It takes some time to recover from that. There’s inflammation, there’s micro-injury, there’re depleted glycogen stores. While some athletes think a single recovery shake after an exercise bout sets us up for the next workout, it actually takes at least 24 hrs to restore muscle glycogen completely after exercise. Note that this is only the case when everything is in place. Unfortunately, many athletes lack a good recovery protocol to support glycogen resynthesis.

Besides glycogen stores we also need to support protein synthesis. Studies have demonstrated that protein synthesis rate is elevated more than 24 hrs post-exercise. When we ingest protein after exercise, it serves as trigger for adaptation and as substrate. It takes a while for our muscles to recover from intense exercise. Rebuilding and remodeling takes time, and it needs more than a recovery shake. Now consider that you’ve probably done a few training days in a row since your last rest day. There’s a lot of suffering your muscles need to recover from.

Finally, some may recognize swelling, reduced range of motion or loss of power and strength at the end of a training block. Exercise causes inflammation (see figure above) and as the degree of inflammation rises, our body reacts with certain symptoms. When we notice any of those, it’s a sign that our body needs rest. Depending on the level of muscle damage, it takes one (lighter exercise) to eight days (eccentric exercise).

All these processes together requires energy. Only with sufficient energy supply it’s possible for our body to recover for the next training day. If our hunger is huge, it shows our body needs more energy to recover. Don’t ignore it, listen to your body, it’s still the best feedback we have when it comes to energy intake. Hunger is a physiological reaction and we shouldn’t fight it. There’s a reason why our body says: hunger!

Wrong Nutrition Tactics on Training Day Increase Hunger on Rest Days

However, energy to support recovery is not the only reason why we are hungry on rest days. In some cases the reason for extreme hunger is what we did the day before. Do you feel hungry especially the day after a hard training day? After a long workout? How do you feel about your training nutrition? How do you feel about your nutrition tactics for a hard training day? If we train a lot, we also need to eat a lot. It’s not so easy to eat the right amount of food and athletes tend to underestimate energy expenditure associated with exercise. Because they don’t eat enough, they finish the training day with a huge energy deficit. Some athletes don’t feel hungry after exercise, hunger is suppressed, and they don’t eat enough. Others don’t eat enough during exercise and finish the workout with a huge caloric deficit, so that it’s impossible to finish the day in energy balance. In both cases we wake up the following morning with a big energy deficit and feel hungry. Sometimes we feel we could eat all day. One snack or the other. It’s because our body’s in such a big deficit and needs energy.

The easiest way to stop this rest day hunger is to revise your training day nutrition. If you’re not sure what you need, it’s best to reach out to a sport dietitian to set up a plan for you. Don’t look for a plan in the internet. A plan needs to be tailored to your personal needs. Sport dietitians can create a plan for you that’s based on your needs. They know what it takes to cover the basic needs. They know what it takes to support performance and recovery. And they help you avoid extreme rest day hunger because you had the right fuel plan the day before.

See also this post on an athlete’s nutrition plan.