Why do we sometimes not lose weight when we exercise?

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There are many health benefits of physical exercise, but sometimes, the one we want is simply weight loss.

There’s nothing more annoying though, than being committed and disciplined on the exercise front and then getting on the scales at the end of the week only to find you haven’t actually lost any weight – or worse still, that you might even have put some on! Before you start smashing your scales and throwing them out the window though, know that all is not actually lost. Things are not always what they seem and you could well be benefitting from the exercise you are doing more than you realise!

So… if things aren’t as they seem, what could be the reasons why your weight isn’t changing?

Weight fluctuates

Your weight naturally goes up and down and during a single day you could weigh as much as 5-6 pounds different at various points!¹ Given that it takes around 3,500 calories consumed to gain 1 pound of fat, you can’t possible have put all of this on in one day. Scales are great as a guide, but they are a reflection of your ‘weight’ and this is not the same thing as body fat. At certain times we might be carrying more water, so the number on the scales could be greater, but this does not mean we have gained ‘fat.’

Gain muscle whilst losing weight

If you are exercising, you are most likely gaining muscle, and this can show up on the scales.
Not all pounds on the scales are created equal though and if you look at two people who are the same height and weight, they could look very different. This is down to a number of factors – water retention, body composition and the overall shape of your body, but it’s also because muscle and fat have a very different density. It’s often heard that muscle weighs more than fat. This is itself is incorrect. A pound of muscle, and a pound of fat, both weigh the same. They do not look the same though. A pound of cotton wool, for example, is going to be physically larger looking than a pound of steel.

Not keeping track of what you are eating

It’s not always a factor, but are you actually consuming more calories than you need without realising? It’s easy to fall into the trap of believing that if we are exercising more we can eat more, and to a degree, this is absolutely correct. You do need more calories to fuel your body if you are frequently enjoying a good movement workout… but we don’t always need THAT MUCH more. Try snacking on high-protein foods that have been proven in studies to keep your fuller for longer and are more likely to help you with continued weight loss.²

Not eating whole foods

Whole foods are rich in vitamins and minerals, don’t contain any chemical additives and are largely unprocessed. They are things like apples, bananas, broccoli, tomatoes, brown rice, whole eggs and salmon. As these foods are nutritious, they give our bodies what they need to function optimally. A diet rich in processed foods on the other hand, can slow down weight loss in a number of ways. Firstly, it often won’t contain enough iron, which is needed to move oxygen around the body and can limit your ability to burn calories through exercise.³ Whole foods also don’t contain refined sugars, which are associated with obesity and have been shown to increase production of the hunger hormone ghrelin which reduces your brains ability to make you feel full.³

Not lifting weights / resistance training

The health benefits of physical exercise are most evident when you combine different types of movement workout. Often, it can be too easy to think that if you are spending all of your time on cardio, then that’s good enough. You can give your muscles a far better workout though – and fuel weight loss – by mixing up your routines with weights or resistance training. While weight training doesn’t burn as many calories during the session as cardio will, it is more effective at building muscle. Muscle burns more energy throughout the day than fat does, so the more muscle you have, the more calories you will be burning, even when you’re not doing anything!⁴

Not doing cardio

The opposite is also true. Weightlifting and bodyweight resistance exercise are fantastic for making you physically stronger, but overall, cardio burns more calories per session than weight training will. The evidence points to cardio being what makes you fitter and helping to fire up your metabolism, leading to better weight loss in the long run.⁵

Not sleeping enough

Studies have shown that not getting enough sleep can have a direct impact on your ability to lose weight as the biological mechanisms that kick in when we are tired make us hungry and inclined to eat more than we actually need in order to achieve a quick burst of energy.⁶ Additionally, evidence suggests that your metabolism will not work optimally if you are tired during the day,⁷ so even if you can resist the chocolate biscuits, your body won’t be burning calories as it usually would be anyway.

The bottom line is that daily and even weekly fluctuations in your weight are rarely a cause for concern and are perfectly normal – albeit sometimes frustrating! As long as you are following a healthy diet, getting enough varied exercise and having a good night’s sleep, any ‘stuck’ scales will soon start moving in the direction you want them to again. Also remember that scales are just one way to measure your progress but there are other ways too. You can take monthly measurements to see how your body shape is changing, consider how your clothes are fitting and most importantly, pay attention to how much better you are feeling.

1. https://health.clevelandclinic.org/when-is-the-best-time-to-weigh-yourself/ [↩]
2. https://academic.oup.com/ajcn/article/101/6/1320S/4564492?login=true [↩]
3. https://www.ncbi.nlm.nih.gov/books/NBK54103/ [↩] [↩]
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2980962/ [↩]
5. https://www.sciencedirect.com/science/article/abs/pii/S1521691804000836 [↩]
6. https://link.springer.com/article/10.1007%252Fs13679-012-0026-7 [↩]
7. http://www.tgiscience.com/documents/Sleep%20and%20Weight%20Gain.pdf [↩]