Dragon Ride (Wales, 9th June)
The Dragon Ride, at 130 miles, and 3400m of climbing is easily the hardest ride I have done in a long time (perhaps ever!). I thought I rode it conservatively, but the zone distribution chart below shows that I spent the majority of the time in the lactate accommodation zone, and about half that time in zone 1. Fuel use in zone 2 is predominantly carbohydrate, with fat oxidation basically ‘killed off’ by the acid conditions of the muscles in this zone, whereas fat use for fuel can be up to 50% in zone 1, allowing the limited stores of glucose and glycogen in the muscles to last much longer.
Precision Pulse reckons I used 5200 kCal, and the body stores roughly 750g of carbs, which equates to 3200 kCal, so that leaves 2000 kCal, or nearly 500g of carbs to be absorbed over the 8hrs of riding if I was running purely on carbohydrate. This would only be possible with a really optimum fuelling strategy of glucose + fructose allowing 60g of carbs per hour to be absorbed, and from previous posts in this series you may remember that my re-fuelling performance is far from optimum. In practice the kCal deficit to be made up was less than 2000 kCal, perhaps nearer 1000 kCal, and of course the body will not allow anyone to use up all their precious glycogen stores (or hypoglycemic coma will certainly stop you exercising at some point).
This being an almost Herculean effort, you won’t be surprised to see a BIG drop in HRV on the Monday, and also a steady decline during the week. I did feel tired and lacking energy during the following week, and did not push any intensity in training, but still the decline was not really what I expected. I need to have a look at previous big events to see if there were similar patterns or if this was unique.