Gareth Rees – Cyclissimo’s Head of Performance Improvement, identifies the key principles for endurance athletes, particularly cyclists, to bear in mind.
For distance cyclists, it’s vital to have a basic understanding of how to fuel the body for effective performance. Regardless of the percentage of carbohydrates, fat and protein eaten, it is important that the calories burned should be matched by the calories consumed. The same is true for hydration. Experience and experimentation will allow individuals to determine their personal baseline requirements for calorific, electrolyte and water intake per hour. However it is important to provide all cyclists with guidelines so that during long distance events and training they avoid the dangers of "hitting the wall" as the marathon runners term it.
All cyclists need to understand the effects on performance of dehydration. In simple terms, 3% dehydration equates to a 10% loss in strength and an 8% loss in speed. While a 5% decrease in body mass due to dehydration, leads to a 30% decrease in endurance performance. With negative effects becoming evident within 15 minutes of starting to exercise.
In a sport where balance, visual acuity and decision-making are vital in respect of safety, we all need to be aware how significantly these can be compromised by dehydration.
The volume of fluid consumed during prolonged activity varies significantly and depends, to a degree, on the performer’s size; the duration and nature of the event; the terrain; and the ambient temperature. It is therefore important for individuals to establish their own rate of fluid loss (sweat rate and respiratory movement), so they can minimise their fluid, and electrolyte, loss or gain.
The simplest checking process is the ‘pee test’. As a general rule cyclists should have the urge to "go" at least every hour. Urine colour indicates hydration levels, ideally it should be very pale yellow or clear. A darker yellow is usually an indicator of dehydration.
The simplest way for an individual to learn their rate of fluid loss is to step on the scales before and after a long, demanding ride. If they weigh less after they should be drinking more, if they weigh more they should cut back to avoid the issues related to "over-hydration". A more scientific process entails pre and post weighing and a simple mathematical calculation, for example:
- Weight prior to ride = 80kg
- Weight post ride = 78kg
- Volume of fluid intake during ride = 1.5 kg (1.5 litres)
- Ride duration = 2 hours
- Volume of fluid loss = weight variation + fluid intake
- Divide that figure by duration to give hourly fluid intake requirement
- Therefore in this example: 2kg weight loss + 1.5kg fluid intake weight = 3.5kg
- 3.5 kg = 3.5 litres (fluid requirement ) divided by 2 = 1.75 litres per hour
Whatever the volume it is important that people appreciate the need to drink regularly as the body can only absorb fluid at a certain rate. A failure to follow this protocol can result in people feeling uncomfortably bloated and deriving little physical benefit from the fluid consumed.
It’s impossible to give precise figures to each individual as individual, climatic and activity intensity vary significantly. However, as a base line, cyclists should sip 12 - 16 oz (1/2 to 3/4 pint or 400ml to 500ml) in the period between 4 to 2 hours prior to starting a ride. In the period 2 hours to 30 minutes prior to starting a similar volume should be consumed. While on the ride the average rate of consumption should be: 16 oz / 500ml / 3/4 pint, per hour in cool conditions up to 3 times this volume in very hot weather.
The key to success is discipline and consistency. Try it for yourself and work out what suits your body best, then stick to it.