What happens to body fat when you exercise? Your muscles first burn through stored glycogen for energy. “After about 30 to 60 minutes of aerobic exercise, your body starts burning mainly fat,” says Dr. Burguera.
"In general, muscle is not lost before fat—it is very dependent on nutrition and activity volume," Miranda-Comas says. "A person who is attempting to lose weight by not eating may lose weight in muscle first before fat."
When you're fasting, your body may use a combination of fat and muscle for fuel. However, your body may prefer one source of energy over another based on your activities and type of fasting.
Your body does not burn fat into muscle. It can take the energy from fat oxidation and use it to help build muscle tissue. This process can occur in as little as 6 weeks of proper training and dieting.
“Not using certain muscles enough, a sedentary lifestyle, and improper nutrition are some of the leading causes of muscle loss,” says Dr Sharma. In fact, your exercise, combined with that calorie deficit can make you lose muscle instead of fat.
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.
As protein degradation exceeds protein resynthesis your muscles are shrinking and your metabolism is likely requiring less calories to support the muscle. If you are losing muscle and you seem to be increasing body fat, it is most often due to a caloric surplus from not moving as much and consuming too many calories.
Eat More Lean Protein
Finally, it prevents excessive muscle loss that could happen during a cut. Target at least 1g of protein per pound of bodyweight, and get your protein from clean sources like lean meats, nuts, eggs, fish, and quality supplements.
It is believed that one's metabolism is at its peak during the teenage years when one can eat anything they want without the fear of gaining kilos. By the time they reach midlife around the 30s and 40s, it starts to decline, and it becomes difficult to keep the weight off.
The first stage of weight loss is when you tend to lose the most weight and begin to notice changes in your appearance and how your clothes fit. It usually happens within the first 4–6 weeks ( 1 ).
Excess visceral fat can pose serious health risks, but when you embark on a healthy diet and exercise plan, this fat is often the first to disappear. This means you're likely to notice weight loss in your abdominal area first. Too much visceral fat can make your belly protrude.
Muscle atrophy can occur due to malnutrition, age, genetics, a lack of physical activity or certain medical conditions. Disuse (physiologic) atrophy occurs when you don't use your muscles enough. Neurogenic atrophy occurs due to nerve problems or diseases.
Can muscle turn into fat? A common misconception is that fat will replace muscle if you stop exercising. "It's absolutely not true," says Petty. "Fat cells and muscle cells are different structures and are not interchangeable.
Some research suggests that you can start to lose muscle in as quickly as one week of inactivity - as much as 2 pounds if you are fully immobilized (3). And another study suggests your muscle size can decrease by about 11% after ten days without exercise, even when you aren't bed ridden (4).
While everyone loses weight differently, dropping as little as 3 to 5 pounds can show up on your face first, Eboli says.
The triglycerides release fat as carbon dioxide and water atoms during fat metabolism or oxidation. In other words, fat leaves the body as carbon dioxide when you exhale. The fat which becomes water mixes into your circulation until it's lost as urine, tears, sweat and other bodily fluids.
Women tend to lose weight all over, and experience fat loss first in their belly, breasts, and arms. Generally the last area they lose weight is from their lower body (hips and thighs). Depending on body shape, men generally tend to lose fat first from their trunk, followed by their arms and then their legs.
Does the act of sweating burn fat? Unfortunately, no. However, sweating could be a good indicator of fat loss and calorie burn. When you sweat during exercise, it's typically because you've engaged your metabolism.
If you are on a low-carb diet, it will help you lose weight as there will be water loss from glycogen in the muscles. But in this case, fat will not burn. Also, if you are doing cardio, you may lose weight quickly but burning belly fat might take time.
Muscle is denser than fat.
While one pound of fat weighs the same as one pound of muscle, muscle occupies about 18 percent less space. In addition, muscle burns calories while fat stores them. So, if your weight isn't decreasing but your clothes are starting to fit more loosely, you may be building muscle.
All in all, it can take anywhere from one week to several months to see noticeable weight loss results. It all depends on your daily activity level, your exercises, and how much you eat each day.