You're depriving your muscles of the amino acids they need to rebuild and recover. You're not replenishing the stored glucose (glycogen) in your muscles which can lead to further muscle breakdown. You'll get hungry a few hours later and likely overeat at that later meal.
Energy Levels: Not eating after a workout can lead to fatigue and decreased performance in subsequent workouts. For optimal recovery, aim to consume a balanced meal or snack containing both protein and carbohydrates within 30-60 minutes after exercising.
If you don't eat after a workout, it can lead to problems such as low energy, dehydration, poor muscle recovery, low electrolyte levels and low mood. Additional symptoms that can arise as a result of not eating after exercise include muscle weakness, muscle fatigue, muscle cramps and irritability.
You will lose muscle first before anything else. Your recovery after training will require further calories which will burn more muscle so you lose 2x times the muscle. The retaining of muscle in a caloric deficit is tricky itself and to not eat anything is a complete downhill way to approach lifting.
By not eating back exercise calories recovery takes longer, your muscles feel zapped the next day, you break down muscle rather than repairing it and exercise becomes too hard, so they tone it down and the net result is no weight loss.
Most adults do not need to eat back their exercise calories because they are doing moderate activities, like walking, biking, swimming, weight-lifting, etc. These activities do not burn enough calories to require a post-workout snack, particularly if weight-loss is the intended goal.
Lifting and doing strength training without adequate nutrition, especially without enough protein, can actually lead to loss of muscle tissue. Furthermore, if you aren't eating right you won't have the energy to do the workouts that lead to muscle gain.
"A person who is attempting to lose weight by not eating may lose weight in muscle first before fat," he says. How does that happen? Well, the body likes to go for carbs (glucose) for energy first.
Overtraining and undereating can not only cause you to lose efficiency, but it can also cause you to lose muscle mass. If you have weight loss goals, eating less may sound like a good idea, but if it doesn't align with your fitness goals, you won't see the results you're hoping for.
When you exercise in a fasted state — after a night's sleep and before you eat breakfast — then you do actually use more fat as a fuel source during exercise. But research from my team has shown that performing exercise in a fasted or fed state does not have any meaningful impact on body fat in the medium to long term.
Symptoms and warning signs of overtraining
“It's natural and expected to feel fatigued after challenging training sessions,” Dr. Goolsby says. “But feeling like you aren't recovering between sessions or experiencing overall fatigue and difficulty pushing yourself during workouts can be indicators of overtraining.”
You're depriving your muscles of the amino acids they need to rebuild and recover. You're not replenishing the stored glucose (glycogen) in your muscles which can lead to further muscle breakdown. You'll get hungry a few hours later and likely overeat at that later meal.
Think about your fitness goals. For example, if your goal is to boost your metabolism and start the day energized, morning workouts may be more suitable. If your aim is to improve performance and relax after a stressful day, evening workouts might be better. Consider your temperature preferences.
Blood glucose at 1-hour postexercise was 3.3 mmol/L lower than the pre-exercise level in the HIT group, and 6.3 mmol/L lower in the moderate exercise group (P = 0.021).
Not eating after a workout is counter-productive and unlikely to increase fat loss. Diet mindsets encouraging food restriction can interfere with your ability to reach your wellness goal, whether weight loss, athletic performance, muscle building, or general health.
However, exercising on an empty stomach will also cause you to lose lean muscle mass at the same time, which can hinder long-term weight loss. Exercising without eating first can cause dramatic shifts in your blood sugar, and when it drops quickly you can feel nauseous, light-headed or dizzy.
Simply put, the more you exercise, the greater your risk of getting hurt. That's just math. But it's more than that. Working out every day—especially engaging in the same types of workouts that target the same muscle groups—means you're stressing your muscles and joints and not giving them time to rest and recover.
Lower Energy Levels and Strength – Without enough protein, energy levels may dip, leading to sluggish workouts and decreased performance. Protein helps regulate blood sugar levels and supports muscle function, both essential for sustained energy.
There are other terms for this, such as build mode, but bulking is a common term for this caloric surplus. Dirty bulking is when an individual is in a caloric surplus to build muscle (build mode). However, the individual is eating foods that are carb dense, unhealthy, and ultra-processed out of convenience.
Eat after you exercise
Eat a meal that has both carbohydrates and protein in it within two hours of your workout if possible. Eating after you work out can help muscles recover and replace their glycogen stores. Think about having a snack if your meal is more than two hours away.
Aerobic exercise includes any activity that raises your heart rate such as walking, dancing, running or swimming. This can also include doing housework, gardening and playing with your children. Other types of exercise such as strength training, Pilates and yoga can also help you lose belly fat.
Skipping lunch means skipping a main meal. Since usually the amount of calories that people receive in their main meals is considerable, skipping lunch can have a significant effect on reducing total calories intake compared to skipping snacks. Reducing the intake of calories in turn leads to weight loss.
The Science of Fat Loss
Think of it like a balloon losing air—it deflates, but doesn't disappear immediately. Over time, your body adjusts, but the jiggly feeling can be a temporary step along the way.