Started Exercising But The Scale Is Going Up?! This Could Be Why!
So you've just started your new exercise regime and you’re so excited and motivated. But then, the first week in you step on the scale and it’s gone up! How could that be!! You then get discouraged and your new regime goes down the drain. NOT SO FAST! There is a reason for this scale increase and it’s not because of fat gain!
What you’re experiencing is called the “exercise plateau” and it is due to water weight increases that are caused by a recent change in exercise. This is very common and happens to anyone who has just done a big change-up in their exercise routine. There are two things going on here, so let me explain.
- Blood volume - exercise causes an increase in blood volume. This happens immediately after exercise, especially if you are dehydrated. The kidneys always respond to a dehydration bout by boosting blood volume later, as a defence against future dehydration. Overall, the kidneys boost blood volume by about 20% in your first week of exercise. This is followed in week 2 by blood cell production by the bone marrow, which adds additional weight. This adds up to a several kilogram increase in weight across the first two weeks of a new exercise routine. This is all a good thing! Increased blood volume is one of the classic adaptations to cardio and it is a sign of increased fitness levels. Fit people often have at least a litre more blood (sometimes more!) than unfit people, which means more nutrients flowing around the body. But don’t forget that a litre of blood weighs 1kg!
- Muscle soreness - any exercise, especially resistance training, that breaks muscle fibre (this is a good thing - you break muscle fibres when you exercise and then they build back stronger), is going to cause inflammation-related water weight. The inflammatory response of sore/recovering muscles always includes some localised edema as swelling = water weight. This is normal and it is part of the muscle’s healing process.
This swelling is so consistent that muscle size (post-exercise) is used to study muscle soreness. For example, sore quadriceps (the muscle at the front of your upper leg) can cause an increase of 30% in thigh circumference for 3 days, almost entirely due to local edema. If you have several big muscle groups with this sort of soreness, there can be a noticeable gain on scale weight.
What about muscle growth? Increased muscle mass can also occur and affect the scale weight but this typically takes much longer. It’s also a slower increase because muscle gain takes time and patience. A professional bodybuilder puts on 250g of muscle a month and that’s a professional!
The “exercise plateau” is a real thing and shouldn’t discourage you from your new exercise regime. Blood volume and muscle soreness scale weight gain usually adds a few kilos on the scale within the first few weeks of exercise and can mask your underlying body fat loss for up to 3-6 weeks. As mentioned above, the blood volume will stay with you for as long as you do the cardio - which is a good thing! But the inflammation in the sore muscles will pass. There is typically a “whoosh effect” somewhere around weeks 3-4 where scale weight suddenly drops, so keep up the good work and try to focus on the non-scale successes such as increased energy, your clothes fitting better, and your new healthy eating habits.