The effects of exercise on our appetite

Have you ever wondered why you lose your appetite after HIIT but are ravenous when you get back from a run? We ask David Wiener, training specialist at Freeletics, to explain the science behind post-workout hunger and the effects of exercise on our appetite…

How does exercise affect our ‘hunger hormone’?

To fully understand the link between exercise and appetite, we must first explore the hormone ghrelin – nicknamed the ‘hunger hormone’. Ghrelin is a hormone that is produced and released by the stomach. It has numerous functions and has been termed the ‘hunger hormone’ because it stimulates appetite, increases food intake and promotes fat storage.

Due to this hormone, it means that appetite isn’t purely based on how many calories you burn during the day, but also to do with what you eat. By avoiding sugary food and eating high protein diets, you can help reduce the level of ghrelin in your blood.

Moreover, not all exercise affects your appetite in the same way. While intense exercise burns more calories than a walk, harder workouts tend to temporarily suppress appetite, while low-to-moderate intensity exercise can make you feel hungry quickly. This is because during a challenging routine your body shuttles much of its blood supply to the heart, brain and muscles. Meanwhile, your digestive system gets more or less abandoned.

How hungry should I be after:

Running

Running is likely to spike your hunger, specifically long runs, this is largely because of the number of calories you have just burned off. Your body will need to replace the energy that it has just used. Following a run, an apple or banana with peanut butter is the perfect snack. The natural carbs from the fruit and the fats from the peanut butter work simultaneously to help you recover but also curb your hunger for the rest of the day.

HIIT

Short HIIT workouts can often suppress hunger, but this is only for a short period of time after your workout. When you complete a HIIT workout, at first your body is still supplying all your muscles with blood rather than your stomach and digestive system, so your body won’t be secreting as much ghrelin. An egg white omelette with loads of veggies is one of the best meals to eat after a HIIT workout. HIIT workouts are short and intense so it’s best to focus your post-workout meal around protein, which is key in building and repairing muscle.

Weight training

Weight and strength training are likely to leave you with a big appetite afterward. As your muscle tissue repairs, it cries out for food to help it regain strength. Similar to HIIT training, after weight training you must eat a meal that is high in protein, carbs and fats. For example, poached egg and avocado on sweet potato.

Yoga

Since yoga is all about your mind and body and finding inner peace and stability, you will find yourself in that relaxed state of mind. Thinking mindfully will cross over into mindful eating, which means you will be more aware of what you are eating. Yoga will also affect your breathing and digestion, helping to curb unwanted cravings and keep you fuller for longer. After yoga, you’ll want to refuel with a meal or snack that has a 3-to-1 ratio of carbohydrates to protein, which can help repair muscle tissues and restore energy levels. Some of the best post-yoga snacks would be Greek yogurt with fruit, nuts, and granola or a quinoa bowl with veggies and tofu.

Why am I starving on rest days?

If you’re hungrier on rest days, it may be that you are under-fuelling your heavier training days. Try increasing your caloric intake on days your body needs it the most, and see if that lessens your cravings on the next day without training. Your rest days should include carbohydrates to restore your glycogen levels and drink plenty of water to help deliver nutrients around your body and to your muscles.

Main image: Shutterstock

By Sam

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