In sports where power to weight ratio is a factor many athletes will seek to shed pounds (kilograms) so that they are lighter and faster. The reality is a bit more complicated; if you are looking to achieve your 'perfect race weight' here are a few things to consider.
Mass and weight clearly effect speed because they increases resistance, this is the reason why the bike market is focussed on making lighter and lighter bikes. You could argue that 'being lighter' is a way to 'free speed' in that you can make yourself faster without training.
However, getting fitter also makes you faster and the benefits of being fitter go beyond raw speed. Being fitter means having a healthier heart, being stronger and increasing longevity.
Whilst excess fat is also a health concern, for someone of a generally healthy BMI, the gains from extra fitness are likely to be more productive, healthier and more long-lasting than shifting to an unhealthy (too low BMI) for some free speed, which is not sustainable longer term.
If you look around at the start of any race or event you do you will see people of all shapes and sizes. From muscle size to bone structure no two people are exactly the same.
In addition to this, we now know that muscle structure can vary from person to person, some people have more fast twitch muscle fibres, some people have most slow twitch muscle fibres.
We also now know that some people seem to be more anaerobic while others are more aerobic, which affects both our top end speed and endurance capabilities.
As a general rule, women need more fat in their body composition than men (we are also better at burning it during exercise).
Given all these differences, it is my belief that there is no real formula that you can use to work out what your perfect weight should be.
Whilst you will definitely notice if you are carrying an extra kilo/pounds that you don't need, there is not an infinite line in which being lighter means going faster. In fact if you are too light you will lose muscle mass, your body will not have enough fats and it will start to shut down compromising performance.
Jonas Abrahamsen, the professional cyclist is a case in point; he found that low weight was hindering his performance and made a concerted effort to gain weight. In an interview with Velo he stated, 'Maybe I have some fast muscle fibres, but when I was too skinny I couldn't use them.' Abrahamsen gained 20kg and held the King of the Mountains jersey at this year's Tour de France for 10 days.
If you read my article on RED-S (Relative Energy Deficiency in Sport) you will know that under-fuelling is dangerous to both your performance and your long-term health.
This is why in general terms it's hard to make fitness gains and lose weight so if you are over weight, unless it is critical to your health or is stopping you from doing your sport it's better to look to lose weight in a base period of training.
Experiments used to estimate how much time you gain/lose per lb/kg of excess/less bodyweight which simply add an extra weight or provide a reduction with the use of pulleys are not replicating body weight gain.
If the extra weight is muscle this can make you more powerful, as in the case of Abrahamsen, and therefore increase your speed.
Getting weighed with body composition scales can be helpful but for some people, it is better for their psychology to avoid the scales and just focus on being healthy. If you do want to weigh yourself, we just got a Garmin S2 scale that we have found to be excellent as a way to look at changes in body composition, although the accuracy of these scales in absolute terms is still developing.
Another way to improve both performance and endurance is to ingest carbohydrates during your event; for ultra endurance events ingesting up to 90g of (mixed) carbohydrates has shown to improve performance and prevent hypoglycaemia. At Endurance Bike and Run we use NeverSecond products to fuel our training and racing.
Additionally in cycling increasing your aerodynamics is another way to get 'free speed' which holds no health risk. When Karen Darke broke the land-speed record for a hand-bike it was not her weight (which was healthy) but the design of the pod and her own fitness that helped break the record.
Ultimately, the gains that can be made for most athletes through weight loss are marginal in comparison to the gains to be made from increasing fitness. The potential risks to your health are unlikely to be worth it.
If you would like some more in depth guidance on nutrition you can book an appointment with us; there is currently a special offer until the end of August 2024 using the link NUTRITION30.