You will first ride on a cycle ergometer at the sports science institute in Cape Town with your own bike attached so we can determine your PPO, followed by an established cycling exercise protocol to deplete your muscle glycogen.
You will then have to follow a 3 day low carb diet, (we'll give you a the diet plan) plus you'll get sports drinks from us which you will have to drink over these 3 days. These drinks will either be a high carb drink or a low carb drink, but you won't know which drink you'll receive when because the drinks look and taste the same ie: you are so-called 'blinded' to the intervention. Those participants that receive the high carb drink will increase their muscle glycogen levels, where the others will stay low - we know this to be true based on and confirmed by lots of previous research.
You will then come back to the lab for the actual data collection ie: you'll ride a 15min steady state at 70% PPO, followed by a 40km time trial performance ride, followed by another 15min steady state ride. During this ride i will have to measure your blood glucose concentration via the finger prick test as used by diabetics 5 times. I will also ask you at certain intervals to give me your Rating of Perceived Exertion, based on the validated Borg Scale (we will explain the scale during your first session ie PPO/depletion ride).
And then we need to repeat this whole test ie: the depletion ride, followed by the 3 days of low carb diet and drinks, followed by the performance ride approximately 4 weeks later. So each participant serves as his own control ie comparing apples to apples.
If you had the high carb drink in the first round, you'll get the low carb drink in the 2nd round and v.v. But you won't know when you get what.
After the data analysis, we'll know how the different muscle glycogen concentrations affect your performance and perception of effort/fatigue.
Informed Consent Form - Muscle Glycogen Study.pdf
