If you always lose your appetite for an hour or two after a workout, you’re not alone. Actually, it’s what’s supposed to happen. Let’s talk about why this occurs.
There’s several physiological adaptations that take place to make you feel this way from elevated core temperature, blood dispersion and hormonal fluctuations. Physical activity stimulates a higher body temperature, and to avoid overheating, the body focuses its energy on cooling, which stops brain receptors that typically signal hunger.
Other reasons why it may suppress appetite is because some high impact sports such as jumping, running or HIT training in general create a lot of stomach movement, causing the stomach to bounce up and down which could make the stomach nauseous and not desire food. Another normal effect of exercise is blood volume and flow gets diverted away from the gut to bring more oxygen to working muscles, slowing digestion and creating a sensation of fullness. To support performance, hormones are also disrupted, including those that regulate appetite, like the hunger-promoting hormone ghrelin (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3761859/). Depending on the individual and type of training, one or all of these factors might be to blame for your lack of desire to eat.
Should you fuel up right away post workout?
While counterintuitive, you should fuel up with in 30 minutes-1 hour post-workout. There are several reasons for this, number one it starts the process of recovery. Your body has elevated stress hormones post workout. Getting your body to a rest and digest in a timely manner will influence your recovery, not just muscular but your nervous system as well. Although getting your calories in post workout is important, proper total calorie intake over the day/week/month/year is what matters most (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142015/)
Another problem when waiting to eat when you’re hungry post workout is you tend to over eat when you do get hungry. After a workout, your body will sometimes try to make up for the calorie gap if it senses there has been a large disruption and you can tend to overeat. Better yet, just have a protein shake/bar post workout to hold you over till you can have a complete meal. If you know you’re going to eat with in an hour post workout then you should just wait to eat then.
For athletes focused on performance and longevity in sport, consuming nutrition post-exercise is crucial. Insufficient energy intake after training is thought to impair muscle protein synthesis, promote accumulated fatigue, and reduce future capacity for training. However, many athletes skip immediately refueling due to simply not feeling hungry.
While not every workout needs to be immediately replenished, efforts leading into key race prep, are longer than 90 minutes, are high intensity, and take place within 24 hours of each other should include recovery nutrition. This promotes ongoing performance gains, lean tissue building, good health and injury prevention.
The average fitness Joe/Jane should opt for at-least 1:1 post workout carbohydrates to protein(c:p)ratio depending on their goal but most likely 2:1 c:p.
Endurance athletes should opt for a 3:1 or 4:1 ratio of c:p while strength athletes, and those looking to improve body composition, should aim for a 2:1–3:1 combination. Professional athletes refuel with a simple mix of water, carbohydrate sports drink and a scoop of protein powder. It isn’t delicious, but it is efficient. Chocolate milk, eggs with jam and toast, Greek yogurt with fruit, or a simple turkey sandwich are all good recovery options. In the end, executing recovery nutrition with a small snack after key training sessions helps you maintain your health and fitness goals.