How Exercise Affects Appetite and Hunger, and What This Means for You

Have you ever finished a workout and felt like you need to eat a huge meal? Have you finished a workout and felt like you weren't hungry, even though you thought you would be? Both of those situations are realistic examples of how exercise impacts your appetite. You may think exercise will always make you hungry, but it's actually more nuanced than that.

Exercise has the ability to either increase or decrease your appetite, depending on the type of training you are doing, your physiology, and your current diet. Knowing how exercise affects hunger can help you plan your pre and post-workout nutrition as well as strategize your meal intake to boost the fitness progress you're working toward.

Hunger vs. Appetite

Hunger and appetite are not one and the same. Hunger is a physical sensation caused by hormones and chemical reactions that occur when your body senses that it requires more food. This reaction can happen for a variety of reasons.

Appetite is a psychological reaction that can be a learned response or occur due to triggers like boredom, emotions, seeing, or smelling tempting foods. These triggers can cause you to eat even when you're not hungry. Several hormones regulate hunger, appetite, and digestion.

The terms hunger and appetite are often used interchangeably, even in scientific literature, but using the words to describe separate functions is helpful for explaining the differences between psychological and physiological desires for food.

Hormones That Control Hunger

There are several hormones and hormonal interactions that influence hunger. Understanding how these hormones affect hunger will provide context for how different forms of exercise interact with these hormones and, therefore, hunger. Here are the significant influencers:

• Leptin: Increased leptin levels trigger the hypothalamus to decrease hunger. Leptin is secreted by adipose tissue (body fat) into the bloodstream. Higher levels of leptin coincide with higher body fat levels and increase with food intake.
• Ghrelin: Ghrelin works with the hypothalamus to increase hunger. It is produced by the stomach and small intestine when your stomach is empty.
• Adiponectin: Adiponectin is secreted by fat cells and goes up as your level of body fat goes down. Conversely, when your body fat levels increase, your adiponectin levels decrease.
• Cholecystokinin: Cholecystokinin is produced in the small intestine during and after eating. It triggers bile and digestive enzymes to release into the small intestine, suppresses hunger, and increases feelings of fullness.
• Peptide YY: Peptide YY suppresses hunger for about 12 hours post-meal. It is produced in the large and small intestines.
• Insulin: Insulin regulates blood sugar levels and suppresses hunger. It is produced in the pancreas.
• Glucocorticoids: Glucocorticoids in excessive amounts increase hunger while a cortisol deficiency can reduce hunger. They are made by your adrenal glands and have several functions including regulating inflammation.
  

The Effects of Intense Exercise

Research on the effects intense exercise has on hunger points to a blunting effect, meaning that your HIIT session could cause reduced feelings of hunger afterward. This effect may not reduce overall calorie intake on the day of training, but instead, blunts hunger for a while after the workout, according to some research. However, the scientific consensus on this is mixed.

A study that monitored the levels of certain hunger hormones after intense forms of exercise, showed that ghrelin and appetite were suppressed after high-intensity continuous training. Blood samples were obtained immediately pre-and post-exercise, as well as 30- and 90-min post-exercise.

While these effects were also seen with moderate-intensity continuous training, they were highest after sprint interval training. In this particular study, energy intake was reduced on the day after high-intensity continuous training compared to both moderate intensity and the control group which did not exercise. This study monitored calorie intake the day before, day of, and day after the exercise and revealed a decrease in overall caloric intake on the day after.

The Effects of Moderate Exercise

Moderate exercise has been shown to affect hunger, appetite, and calorie intake in various ways. Several studies have shown that most individuals don't experience compensatory changes in hunger after moderate-intensity exercise.

Moderate sustained exercise can suppress appetite with an increase in peptide YY, which suppresses appetite for about 12 hours. What this means is that moderate-intensity exercise, which burns calories, thereby increasing your calorie output, does not cause hunger that leads to increased food intake. That being said, eating after you exercise is crucial for restoring glycogen and repairing muscle.

If your goal is to gain or maintain your weight, or increase performance, you may need to purposefully increase your calorie intake if you participate in exercise. Adding slightly more to your regular meals, especially in the form of nutrient-dense protein and carbohydrates, can support your training and help you gain lean mass.

Strength Training and Hunger Regulation

Strength training can be performed at light, moderate, and intense levels, depending on the type of training you do. For instance, resistance training with more extended sets using multiple reps and lighter weight may not increase the heart rate too much, while powerlifting performed with heavier weights can increase the heart rate to near maximum.

Strength training, however, is unique from traditional cardiovascular training in that it causes more damage to the muscles than other types of exercise often do. This type of damage is necessary for muscles to become stronger and larger.

Some research suggests that strength training can lead to a significant increase in appetite.However, others have suggested no increase in caloric intake. If your aim is to build muscle and increase your lean mass, it is likely you will need to make a conscious effort to consume more calories, not only to build the new tissues but to compensate for the calories burned during your training.

How These Effects Can Be Used Toward Your Goals

Adding exercise to your lifestyle provides many benefits to your health and wellbeing, far beyond bodyweight. However, you may also have specific goals related to your weight, including reducing body fat, gaining muscle, fueling performance, or maintaining your weight. In that case, there are some things to consider regarding how your training may affect your appetite.

Weight Gain and Building Muscle

If your goal is to maintain or gain weight, you will likely need to increase your calorie intake when adding exercise to your lifestyle to make up for the calories lost. To build muscle and increase your lean mass, you will need a greater calorie intake with a special focus on getting enough protein.

You can try adding a bit more food to each meal or add an additional meal, such as post-workout refueling. Try to focus on nutrient-dense foods that will fuel performance for the best results, in particular, complex carbohydrates, and lean protein.

Examples of healthy foods to add include eggs, fish, tofu, chicken, lean cuts of beef, beans and legumes, whole-grain breads, starchy vegetables, sweet potatoes, oats, and quinoa.

Weight Loss and Losing Bodyfat

Exercise as part of your lifestyle may lead to weight loss and help maintain weight loss, especially when combined with a nutritious, balanced diet.

If your goal is weight loss, body fat reduction, and weight maintenance, exercising is an excellent way to reach that goal. Resistance exercise, in particular, can reduce muscle loss and subsequent metabolism slow down that can occur during weight loss.

A Word From Verywell

Exercise is an excellent addition to any lifestyle routine as it provides protection against disease and helps you feel your best. There are several reasons you may be concerned about how exercise will affect your appetite. If your aim is to lose weight, you may worry that adding workouts will make you too hungry. The good news is the evidence points to the contrary.

If your goal is to maintain or increase your body weight, perhaps with an aim of building lean muscle mass, you may need to intentionally add calories to your diet to see results. Whatever your goal, fuel your performance with nutrient-dense foods and focus on getting enough protein. If you are confused, a sports nutritionist or dietician can help you create a healthy food plan that works for you.