A small controlled study found that exercising earlier in the day was linked to less hunger and substantially lower food intake than completing the same workout in the evening, while eating before exercise did not meaningfully change post-workout appetite.
By yourNEWS Media Newsroom
The time of day a person exercises may influence how much food they consume afterward, with morning workouts associated with lower hunger and roughly 547 fewer calories eaten over the following 24 hours than identical evening sessions, according to a study involving healthy young adults.
Participants who exercised in the morning also consumed about 400 fewer calories at their first post-workout meal than they did after exercising later in the day. Evening sessions were accompanied by stronger hunger, a greater desire to eat and lower feelings of fullness.
The findings suggest that exercise timing may affect compensatory eating independently of whether a person consumes food before working out. Researchers found that pre-exercise meals changed the amount of fat burned during activity but did not significantly alter appetite or subsequent calorie intake.
The study enrolled 35 healthy young adults and used a repeated-measures design, meaning each participant completed the same treadmill workout under several different conditions. That approach allowed investigators to compare each person’s response to morning and evening exercise rather than relying solely on comparisons between separate groups.
Participants completed 30 minutes of treadmill running during morning and evening sessions. The conditions included morning exercise while fasting, evening exercise after either a six-hour or 12-hour fast, and morning or evening workouts performed after eating.
Researchers monitored how much food participants consumed immediately after exercise and during the next 24 hours. They also recorded subjective ratings of hunger, fullness and desire to eat.
The strongest difference emerged between morning and evening exercise rather than between fasted and fed conditions. Participants consistently ate more after evening workouts, even when the duration of the pre-exercise fast was shortened from 12 hours to six hours.
The extra intake after evening exercise totaled approximately 400 calories at the post-workout meal and about 547 calories across the full day compared with morning exercise, according to the study.
The findings indicate that calories burned during a workout may be partly offset when exercise triggers greater food consumption later. That response could be relevant for people using physical activity as part of a weight-management plan.
Morning exercise did not eliminate hunger, but it was associated with a more favorable appetite pattern than evening exercise. Participants reported feeling less hungry, less interested in eating and fuller after completing the earlier sessions.
Researchers proposed that the body’s circadian rhythms may help explain the difference. Hunger and satiety signals naturally change throughout the day, and evening hours may be associated with stronger biological pressure to eat.
Dr. Cate Shanahan, as cited in Mark Sisson’s book “Two Meals a Day,” has noted that ghrelin, a hormone associated with hunger, tends to rise later in the day, while hormones associated with satiety may be more active during the morning.
Related research has examined whether meal timing can influence metabolism because organs and tissues operate according to internal biological clocks. That work has contributed to growing interest in how the timing of food intake, sleep and exercise may shape health outcomes.
The study also examined whether fasting before exercise offered an appetite advantage. Although working out without eating first increased fat burning during the session, it did not reduce subsequent hunger or calorie intake.
Pre-workout feeding suppressed fat oxidation, meaning the body relied less heavily on stored fat while exercising. That metabolic change did not translate into meaningful differences in how much participants ate afterward.
The result challenges the assumption that fasted exercise necessarily improves weight loss by reducing appetite or producing a larger daily calorie deficit. Burning more fat during a single workout does not automatically mean a person will lose more body fat over time, particularly if appetite and food intake later increase.
A 2025 article similarly noted that fasted workouts may increase fat use during exercise but can also heighten hunger and reduce workout performance. In the present study, however, fasting duration did not explain the higher calorie intake associated with evening sessions.
Even participants who fasted only six hours before an evening workout consumed more calories over the next 24 hours than they did following morning exercise.
The researchers said the findings identify workout timing as a potentially useful consideration for people whose primary goal is controlling appetite or managing weight.
“If you have flexibility in your schedule and weight management is a priority, shifting workouts earlier is a simple, evidence-informed adjustment worth trying,” the study authors said.
They also emphasized that exercise consistency remains more important than selecting a theoretically ideal time.
“The best workout is still the one you’ll actually do consistently,” the authors said.
Evening exercise continues to provide established benefits, including support for cardiovascular fitness, muscle maintenance, strength, metabolic health and mental well-being. The study does not indicate that people should abandon evening workouts when that is the only practical or sustainable option.
Its findings instead suggest that morning exercise may offer an additional appetite-control advantage for some people.
Sisson has argued that calories burned during strenuous exercise may contribute less to fat loss than commonly assumed because increased energy expenditure can be followed by greater hunger and compensatory eating. The present study supports that possibility by showing that identical evening workouts were followed by substantially higher calorie intake than morning sessions.
Exercise timing may also interact with a person’s natural chronotype, or biological preference for earlier or later activity. Other research suggests that matching workouts to an individual’s internal clock may influence blood pressure and additional cardiovascular measures.
The study did not establish that morning exercise will produce greater long-term weight loss. It measured short-term appetite and food intake in a relatively small group of 35 healthy young adults, limiting how confidently the results can be applied to older adults, people with obesity, athletes or individuals with metabolic disease.
Food intake and appetite over a single day may also differ from patterns maintained over weeks or months. Longer trials would be needed to determine whether the observed calorie difference persists and leads to meaningful changes in body weight or body composition.
The findings nevertheless offer evidence that the same workout can produce different eating responses depending on when it is performed.
Morning sessions were associated with lower calorie intake at the next meal and across the following 24 hours. Evening exercise produced stronger hunger and greater compensatory eating regardless of whether participants had fasted for six hours, fasted for 12 hours or eaten beforehand.
For people able to choose when they exercise, moving a workout earlier may help reduce the tendency to replace calories expended during activity. Those who prefer evening exercise can still benefit from planning a balanced post-workout meal and being aware that hunger may be stronger later in the day.
The study’s central finding was that exercise timing influenced appetite more consistently than pre-workout nutrition. Morning workouts were linked to lower daily calorie consumption, while eating before exercise affected fuel use during the session without significantly changing how much participants consumed afterward.
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