Several studies show that you hardly lose any weight only because of training (1) (2). If you do not change your diet the scale will show a lower weight. Why is this and how you can ensure that you lose weight?
If you want to lose weight, you must burn more calories than you eat. A simple calculation already predicts if you will succeed in your attempt, subtract the number of calories you burn each day from the number of calories you get in with food. If the result is positive, then you will lose weight and vice versa (3).
On average, a man burns 2,500 calories a day and a woman in 2000.
That's an average, if you want to know precisely how much calories you burn, then there is a simple formula (the formula of Harris and Benedict) (4).
For men: 66,4730 + (13,7516 x G) + (5,0033 x H) - (6,7550 x L)
For women: 655,0955 + (9,5634 x G) + (1,8496 x H) - (4,6756 x L)
G stands for weight in KG, H stands for Length in CM, and L stands for age.
This formula indicates what is called the 'base metabolic rate'. Base metabolic rate is the amount of energy your body needs to breathe, to build cells, to maintain your body temperature, to make your heart beat without you moving. If you want to include the activities you do in a day, you have to multiply the outcome by a factor that depends on your daily activities:
Little to no exercise
1,4 - 1,5
Light exercise (1-3 days per week)
Moderate exercise (3-5 days per week)
1,8 – 1,9
Heavy exercise (6-7 days per week)
2,0 – 2,4
Very heavy exercise (twice per day, heavy workouts)
It sounds complicated, but on the internet there are numerous sites where you fill out your information and it is calculated for you. Now you know how many calories your body needs per day. Good to know, because if you want to lose weight you should therefore ensure you burn more energy than you get in.
Suppose you need 2100 calories and you want to lose weight, make sure you eat 500 kcal less. You can achieve this by making healthier choices in terms of nutrition and by exercising more (5). Burning 500 kcal daily by exercising is really a lot (swimming for an hour, fifty minutes rope jumping or three quarters running), especially when you know that these extra exercises again cause extra appetite.
So in order to reduce your calories you always combine sports with less and healthier eating! This makes you lose fat. Be aware, exercising is extremely important!
If you want to lose weight for example by just reducing your eating less you will not only lose fat but also muscle mass, and muscle mass is very important. More muscle means more calories burned, even during the rest periods. Fat burning continues in the muscles. So exercising alone is not enough. But to only reduce your eating is also not effective. So it really is about the combination of the two.
Don’t get discouraged when you just started training and you don’t lose weight very fast. If you're just starting an exercise program, it is even possible that you become slightly heavier. You're building muscles and burning fat. Muscles are more heavy than fat. So you are on the right track.
So give it some time. Only after a few months you will notice that you feel better and have more energy, that your fitness has improved and lose weight. Challenge yourself to go a step further. Eventually you'll see a difference on the scale and in the mirror.
Come on! You can do it.
1. Nutrition Center. Lose weight with exercise. Retrieved July 19 2015
2. Johns, DJ, Hartmann Boyce, J., Jebb SA Aveyard, P., & Group, Behavioral Weight Management Review. (2014). Diet or exercise interventions vs combined behavioral weight management programs: A systematic review and meta-analysis of direct comparisons. Journal of the Academy of Nutrition and Dietetics, 114 (10), 1557-1568.
3. Kemper, H. (2013). Nutrition and exercise, is a matter of energy balance. Informatorium nutrition and dietetics-nutrition (pp. 531-546) Springer.
4. Roza, M. A., & Shizgal, H. M. (1984). The harris benedict equation reevaluated: Resting energy requirements and the body cell mass. The American Journal of Clinical Nutrition, 40 (1), 168-182.
5. Kelley, G. A., & Kelley, K. S. (2013). Effects of exercise in the treatment of overweight and obese children and adolescents: A systematic review or meta-analyzes. Journal of Obesity, 2013