When you want to lose weight, you want to lose it ASAP. While you can weigh and measure and track yourself, it's hard to tell how quickly you'll lose weight after exercise. One thing is for sure, though — if you follow an effective exercise program and eat a healthy diet, you will start to see results quite quickly.
If you create a calorie deficit through exercise and diet, you'll begin losing weight. How quickly that will happen depends on many factors, including your age, genetics and metabolic rate.
Exercise and Fat Loss
Here's a rough sketch of what happens when you start exercising to lose weight: Assuming you are controlling your calorie intake, the calories you expend exercising and the boost in your metabolic rate puts your body in a calorie deficit. This means you're consuming fewer calories than your body expends each day.
This is a crucial part of weight loss. Generally, weight gain occurs because of a calorie surplus. You've been consuming more energy than your body needs and it's stored that excess as fat. To lose fat, you have to reverse the process.
Sounds simple, although weight loss involves a lot more than just creating a calorie deficit. How much weight you lose and how quickly you lose it also has to do with age, gender, genetics, medications, medical conditions and lifestyle factors like stress and sleep quality. It's a highly individual matter.
Read more: The 13 Most Creative Weight-Loss Tips Ever
Get a Rough Estimate
There are a lot of weight-loss calculators out there that claim to be able to predict how quickly and how much fat you'll be able to lose in a certain time frame. It's a nice thought, but weight loss doesn't fit into a neat equation. While you can use a weight-loss calculator to get a general idea of your timeline, don't rely on it as fact.
Another theory that should be taken with a grain of salt states that for every 3,500 calories you burn, you lose a pound of fat. Although mainstream health organizations like the Mayo Clinic still use this estimate, many experts are now turning away from it.
According to a June 2014 article in the Journal of the Academy of Nutrition and Dietetics, this theory, proposed in a 1958 report by medical researcher Max Wishnofsky, is outdated and incorrect. Because of the numerous metabolic changes the body undergoes during weight loss, the process isn't so linear or simple.
The Path of Weight Loss
According to the authors of the Journal of the Academy of Nutrition and Dietetics article, weight loss happens quite fast in the beginning of a slimming program and then slows down once the body adapts to the calorie deficit. Don't get your hopes too high, though — most of the weight lost in the beginning isn't fat, but water.
The explanation of what actually happens is rather "science-y," but the gist is that your body loses other substances before it gives up fat. These include proteins, water and a pool of stored carbohydrates.
After the initial phase, your body will begin to oxidize fat for energy. However, weight loss — the number on the scale — will decline with much less rapidity than it did during your early exercise days.
Diet vs. Exercise
Your diet is a major factor in how quickly you lose weight and how much weight you lose. If you don't control your calorie intake and eat healthy foods, you will not be able to lose weight and keep it off.
However, exercise doesn't just burn calories. It can influence your appetite, your food choices and your mood, which helps you make healthier food choices and control your calorie intake. Sometimes, how much exercise you get matters far more than just how many calories you burn.
For example, a study published in January 2019 in the International Journal of Obesity examined dietary patterns of 2,680 young adults. Researchers have found that both moderate-intensity steady-state exercise and high-intensity exercise encouraged healthier food choices and a natural reduction in caloric intake. The effect may be dependent on the amount of exercise, as the researchers stated that more exercise led to less snacking and more prudent food choices.
Additionally, exercise positively affects your mental health, reducing depression, anxiety and stress. The link between mood and food intake is also clear, and often referred to as "emotional eating" and "stress eating." Increasing your mental well-being with regular exercise can also help reduce your food intake for faster weight loss.
The Fastest Fat Burner
So you're ready to get started with exercise — what's the best type to promote fast fat loss? Anything you enjoy doing. That's probably not the answer you were expecting, but it really is the best way to lose weight because it encourages consistency, which is key to fat loss.
If you don't enjoy the activity you're doing, you are likely to be inconsistent. So whether you like brisk walking, hiking, kickboxing, climbing or dancing, do it — and do it regularly. The more exercise you can get each week, the greater the caloric deficit you can create and the more weight you can lose.
To give you some goals to aim for, the U.S. Department of Health and Human Services (HHS) recommends that adults get at least 150 minutes of moderate-intensity cardiovascular exercise or 75 minutes of vigorous exercise each week. For even greater weight-loss benefits, shoot for 300 minutes — or more — of moderate intensity or 150 minutes of vigorous exercise.
Other Benefits of Strength Training
Cardio isn't all you need. The HHS also recommends that adults strength train the major muscle groups twice a week. Not only does this build strong muscles and bones, but it also boosts your resting metabolic rate, which is the number of calories your body burns while at rest. Building more muscle mass means you'll burn more calories each day, even when you're doing nothing at all.
It doesn't matter what type of strength training you do as long as it is challenging. You can do Olympic lifting, circuit training, ashtanga and other types of vigorous yoga, Pilates or barre. These types of workouts also burn calories while you're doing them.
Circuit training and tabata training are particularly good strength-training workouts for calorie burning because they are high-intensity and keep your heart rate elevated. As with cardio exercise, the key is to find something you like to do and do it regularly.
- CDC: "Finding a Balance"
- NIH: "Molecular Ties Between Lack of Sleep and Weight Gain"
- Mayo Clinic: "Counting Calories: Get Back to Weight-Loss Basics"
- Journal of the Academy of Nutrition and Dietetics: "Time to Correctly Predict the Amount of Weight Loss With Dieting"
- International Journal of Obesity: "International Journal of Obesity"
- HelpGuide: "The Mental Health Benefits of Exercise"
- HelpGuide: "Emotional Eating"
- U.S. Department of Health and Human Services: "Physical Activity Guidelines, 2nd Edition"
- University of New Mexico: "Controversies in Metabolism"