10 Reasons Why The Scales Aren't Telling You The Truth?

As cyclists, we are often interested in our body weight (or, more correctly, our mass) on the scales, given the indirect impact it can have on some aspects of cycling performance through its contribution to our power-to-weight ratio.

Many cyclists get hung up on the number, and in some cases, changes in scale weight can induce significant stress and anxiety. This is often the result of a poor understanding of what that change can actually mean and also how culturally embedded it is within many cycling disciplines, from communications with coaches and other athletes to reporting in the media, that a lower weight on the scales is better for performance, despite that often not being the case.

Weight loss isn’t always better for performance due to the poor practices many athletes adopt in pursuit of weight loss. Creating weight loss requires an energy deficiency, which can put an athlete in a state of low energy availability; if severe or sustained, this can result in significant negative impacts on an athlete’s health and performance. From a loss of performance and muscle mass to a reduction in training quality and adaptations. There are many aspects to consider regarding whether or not an athlete will benefit from weight loss, which we’ll cover in a future blog.

First and foremost, when it comes to weight, it's important to consider that performance is influenced by a whole host of different factors, including technical abilities, psychology, aerodynamics, training history, and individual physiology. Body weight is just one factor, and its influence is potentially much smaller than that of other factors.

In this article, I want to highlight some key limitations of examining scale weight by showing you some of the different factors that can influence it, and explain how best to use it.

Athletes often look at the scales and assume changes relate to meaningful changes in body composition (i.e. fat loss or muscle gain), but your mass on the scales can be influenced by many other factors... 

1. Hydration Status – How hydrated or dehydrated we are can change our mass by as much as a few kilograms. If you’ve ever weighed yourself before and after a ride in the heat with significant sweating, you’ll potentially have seen big changes to mass pre and post-riding. I’ve seen athletes lose over 2 kilograms of mass in under an hour of exercise in the heat. Athletes aren’t always the best at rapid rehydration either, and, therefore, a reduction in mass can persist as much as a couple of days post ride if fluid loss isn't adequately replaced. 
2. Sodium Intake – The amount of salt in our diet can influence how much fluid we retain and, our mass.
3. Heat Acclimation—A key adaptation to training in hot environments is an expansion of plasma volume, the fluid component of the blood. If an athlete goes from non-adapted to heat-adapted, this can result in gains o as much as a couple of kilograms. 
4. When you last went to the toilet—This is a straightforward one, but it can have a significant impact on the scales.  
5. Dietary fibre – As we’ve covered previously, going from a modest intake to a low intake of fibre can change body mass by around 500 grams by reducing mass within the digestive system.
6. Timing Of Your Last Meal - Pretty self-explanatory this one, but the volume and size of your meal and how much of it is left within your digestive tract can impact scale weight. 
7. Menstral Cycle - The premenstrual phases of the menstrual cycle can result in fluid retention, adding water weight to the mass reading. 
8. Training Inflammation - Heavy training, particularly that which induces muscle damage, such as resistance exercise or very long rides on the bike, can result in inflammation, increasing fluid retention and increased mass. 
9. Glycogen stores – Going from low levels of glycogen to high levels of glycogen can easily add in excess of 2 kilograms to an athlete's mass, as for every gram of glycogen around 3 grams of water is also stored. With athletes having significant fluctuations in glycogen stores based on dietary carbohydrate intake and the demands of different rides, this can easily account for a significant degree of fluctuation. 
10. Supplementation & Medication – Certain supplements and medications can result in fluid retention (e.g. creatine monohydrate) impacting mass. 

As alluded to, these factors can result in significant fluctuations (by as much as a few kilograms) in a relatively short space of time and often be completely independent of meaningful changes in body composition. 

Whilst there are significant limitations to using scale weight, with a better understanding of factors that influence it we can use it to identify long-term patterns that can be used as an indicator of progress, particularly when combined with other observations (i.e. skin folds/girth measurement) that are better indications in changes in body composition (i.e. muscle gain/fat loss). 

To help control for many of the factors I've outlined above, we can adopt a standardised approach to using the scales. By weighing in first thing in the morning, after going to the toilet, nude, on standardised days per week (i.e. after specific training sessions and no more than 2-3 days per week) can help manage some of the impacts of the different factors outlined above and get a truer reading when looking at trends over time.