Over the years, in my personal training work, I have received many questions about exercise and diet. The topic is often debated among family, at work, in social media, on newspapers, blogs, etc. The opinions are so many and that’s good, but in the middle of so many opinions, it can be difficult to find real answers.
In this article, I will review some facts and myths in exercise and diet. It will hopefully confirm or cancel some of your questions.
15 Myths & Facts about Exercise and Diet
1. You must feel sore the day after a workout for it to work
Muscles can be exercised without aching or being sore afterwards. Your goal shouldn’t be being in pain after a workout.
2. Protein intake must be increased significantly when starting strength training
The recommendations are 0.8g proteins per kg body weight per day. Looking at top athletes exercising over 20 hours a week, the recommendation is 2g per kg body weight per day, while those who exercise less (5h/week) do not need more than 1g per kg body weight per day.
There is no proven effect on increased muscle mass at an intake of 3-4g per kg body weight per day. Therefore, the need for proteins should be covered by a healthy and varied diet in most people.
3. Metabolism decreases with age
Metabolism is at its highest at the age of 20, then declines by about 1% each year. It means that as times change and you grow older, you will not be able to eat as much without increasing your activity level.
4. You may be born with heavier and larger bones than others
The average weight of the skeleton is somewhere between 2.5 – 4.5kg. What constitutes the major part of the body weight is the composition of muscles and fat.
5. If you have not managed to lose weight in the past, you will never do it
Previous trials give you experience and knowledge about exercise and diet that will definitely make you better prepared.
6. Running burns more than cycling
The reason for this is:
– Running requires constant work and you get no “breaks” in the work. Pauses are more frequent in cycling plus in downhill runs where much less energy is required.
– Running demands muscle work of both the lower body and upper body, while cycling mainly requires energy from the lower body, which means that the total energy consumption will be lower.
– Running is a weight-bearing activity. In cycling the bike “helps” to carry the body weight.
7. You burn more fat (kcal/calories) at low intensity vs. high intensity
Total calorie burn is the key to weight reduction, as all the surplus of what you eat will be stored as fat. You burn most fat at 70-75 heart-rate beat, but the total burn will be far lower than at a higher intensity.
– 30 minutes interval – burns mainly carbohydrates – high-calorie consumption. Total caloric burn is around 300-500kcal.
– 30 minutes ‘powerwalk’ – lower calorie consumption. Even if you burn fat, the total burn will be lower (100-300kcal) and you will need more time to lose the weight.
8. Endurance training is better for weight reduction than strength training, although increased muscle mass causes greater caloric burning even in resting period
1kg muscle mass increases resting metabolism by only about 13kcal per day (1), so the fastest way to weight reduction will be endurance training. But, in a longer perspective, an increased muscle mass is of great importance for maintaining a stable weight, as we often see that it is the small transitions (100kcal) over a longer period of time which are a major cause of weight gain (1).
So a combination is recommended, but the biggest impact on weight comes from endurance training.
9. Evening meals increase the risk of being overweight
It is the total calorie intake during the day that counts.
You have a calorie requirement of approx. 2000kcal per day. During the day you have only eaten 500kcal and choose a large serving of 1500kcal dinner. Either way, the total calorie intake is 2000kcal and you are in energy balance regardless of when you eat.
10. Wearing a black plastic bag on hot sunny days will increase calorie burn
All that does is contribute to potential dehydration and fatigue. Heat may actually reduce caloric burn because you get tired faster.
11. Men have more muscle mass than women
The average amount of muscle mass is of approx. 40% of body weight in adult men and of 35% in adult women.
An average man, 80kg – 32kg muscle mass
Average female, 60kg – 21kg muscle mass
12. Breakfast must be eaten to “start caloric consumption”
Caloric consumption is taking place regardless of breakfast. However, it would be wise to have breakfast to increase energy levels so you can get more energy during the day.
13. Specific strength training on the belly reduces belly fat
Specific strength training of the belly does not reduce belly fat. The fat on the stomach is reduced only through higher energy consumption than energy intake. This is done through a good diet and plenty of physical activity.
14. Physical activity strengthens your skeleton
Weight-bearing training such as strength training, jogging, aerobics, dancing, alpinism, etc., has a good effect on bone structure. Maximum bone mass is achieved by the age of 20-30, and it will be beneficial to have, in young age, exercised a lot and done varied exercises to create as strong a bone mass as possible. After the age of 30 and especially after menopause for women, it is important to maintain the training to counter the bone mass decomposition.
15. Stretch after exercise to avoid being sore
There is no evidence that stretching helps in this regard. Stretching will provide increased mobility, which in turn is good for coordination and to counter the stress you’ve just put your muscles trough. Feeling sore occurs when you expose your body to excessive stress, start calmly and increase the load gradually.
By Personal Trainer Øyvind Holt
Originally published on
- Raastad, T., Paulsen, G., Refsnes, P, Rønnestad, B., Wisnes, A. (2010) Strength training – In theory and practice. Gyldendal
- Bahr, R., Activity Manual – Physical Activity in Prevention and Treatment. Directorate of health