Water Retention: Exercising vigorously might cause short-term water retention in the body. Exercise causes the body to release stress hormones like cortisol, which can lead to fluid changes and water retention. This may cause a brief rise in weight that is largely the product of water retention rather than fat.
Post-workout inflammation
You may retain fluid after exercise as your body repairs the damage, which can cause water weight gain. Any uptick on the scale is usually minor and temporary. Weighing yourself regularly can be helpful on your weight-loss journey. Mohr suggests skipping a weigh-in right after your workout.
Water Retention: Intense workouts can cause the body to retain water, especially when starting a new exercise regimen. This can result in temporary weight gain. Increased Appetite: Regular exercise can increase appetite, and some individuals may consume more calories than they burn, leading to weight gain.
It's common for weight to fluctuate after exercise, and several factors can contribute to this phenomenon: Water Retention: Intense exercise can lead to muscle microtears, which can cause inflammation. Your body may retain water to help with the healing process, leading to temporary weight gain.
This water retention phenomenon usually lasts 2-3 weeks while your muscles get accustomed to the new routine.
Muscle weighs more than body fat
If you've only ever done cardio exercise, you may be confused when a strength-training program leads to weight gain. But the reason for it is simple: Weight training builds lean muscle mass, which is denser than body fat.
Muscle is denser (meaning a lot less fluffy) than fat, says Dr. Calabrese. Put another way, 10 pounds of muscle takes up a lot less space than 10 pounds of fat. So, as you start working out regularly and building strength, the new muscle you build may eventually weigh more than the fat you've burnt off.
Stage 1: Fast weight loss
In the beginning, weight loss happens pretty rapidly. Over a period of 4-6 weeks, you'll likely see a noticeable difference in your body weight [1] — either on the scales or by the way your clothes fit.
There are several research-backed reasons why you might notice a slight weight gain after exercise. These include muscle gain, water retention, post-workout inflammation, supplement use, or even undigested food. In most cases, post-workout weight gain is temporary.
For beginners, you can expect to see initial changes in strength and endurance within 4-8 weeks of consistent participation in fitness classes. These initial gains can be highly motivating, improving your physical strength and cardiovascular endurance and providing a solid foundation for future progress.
When you start to exercise regularly, your body accumulates glycogen, stored in water, to better adapt to your activities. After about one month, the normal situation should be restored. Water retention may also occur during the summer.
It is generally not recommended to weigh yourself immediately after a workout, as your weight can fluctuate due to several factors such as hydration level, muscle soreness, and inflammation.
In other words, a pound of fat has a much larger volume. But a pound of muscle appears leaner and more toned. So, an extra 15 pounds of fat will take up a lot more space in your body — giving you a softer appearance. And muscle is denser, meaning it has a smaller volume for its weight.
Mostly, losing weight is an internal process. You will first lose hard fat that surrounds your organs like liver, kidneys and then you will start to lose soft fat like waistline and thigh fat. The fat loss from around the organs makes you leaner and stronger.
Strength training ensures the greatest afterburn effect. Circuit training and high-intensity training (HIT) consume the most calories, but also have the longest recovery time. At very high intensities, metabolism stays elevated for up to 48 hours (Schuenke et al.
Your Body Is Holding On to Water Weight
“Glycogen can rapidly provide energy — in the form of glucose — when needed,” says Dr. McGowan. But because glycogen binds with water to fuel muscles, that water can increase your weight slightly in the initial weeks of a new workout routine.
You're gaining muscle. The scale might be stuck because you're building up your biceps and glutes—and that's a good thing. The number on the scale is less important than the breakdown of how much water, muscle, and fat are in your body, Jovanovic says.
As a rough guide, you'll probably notice some initial changes in the first four to six weeks, but longer-term changes (what you're working toward) will often take around eight to 12 weeks. The good news is that you're likely to start feeling better quickly.
The rule of thumb, Fernstrom says, is that losing 8 to 10 pounds translates to going down one size. Still, if you lose "up to 15 pounds, you may be OK in your old size," she says. But putting off buying new clothes until you really need them doesn't work for everyone.
So as you lose weight, your metabolism declines, causing you to burn fewer calories than you did at your heavier weight. Your slower metabolism will slow your weight loss, even if you eat the same number of calories that helped you lose weight. When the calories you burn equal the calories you eat, you reach a plateau.