Motivated by the Tour de France I went out for a long bike ride yesterday afternoon. Common sense would have told most people that cycling too far, too fast, in baking sunshine, was not the best idea but I am not most people and it seems I have no common sense.
So about an hour and a half into the ride I suddenly lost almost all strength. From whooshing along at 35 kmh I was suddenly barely able to manage 20 kmh. And with at least 20 km left to get home things were looking a bit grim. I had the distinct feeling I was going to fall off the bike at any moment, and didn’t have much water left so was drinking it sparingly. Inevitably I had forgotten to bring the portable phone along.
This, you will note, is why the contestants in the Tour de France eat and drink so much during the race.
This condition of not eating properly is called ‘hitting the wall’ or more commonly ‘bonking’. The body only stores enough glycogen for about 1500 calories worth of effort – less than 2 hours hard cycling – and when that runs out so does your energy. Apparently acute hypoglycaemia and hallucinations set in soon after. Stopping by the edge of the road for ten minutes to recuperate won’t help!
Happily before falling comatose in front of an oncoming truck I remembered that a couple of weeks ago I had squeezed an energy bar into my toolbag and forgottten about it. Well eating that energy bar was an amazing experience – literally within 5 seconds I could feel the strength returning, and within no time at all I was soaring along at tip-top speed again.
After I had got home and made lots of childish jokes about bonking (the use of the word for this condition dates back more than 50 years, it’s not something I dreamed up myself) I looked on the internet and discovered the following:
“Bonk training” is an exercise program designed for weight loss…on an empty stomach first thing in the morning, when glycogen store levels are low: consume coffee or caffeine equivalent to 2 or 3 cups of coffee, run or cycle at a casual pace (60% of max heart rate) for 20-90 minutes, have a normal breakfast right after exercising. Proponents claim this will force the body to “bonk” shortly into the exercise, and subsequently burn more fat to generate the energy. ( wikipedia)
Now I know people can contribute ‘factually incorrect’ information to wikipedia, and the paragraph is followed by a warning that dangers might be involved, but is this for real? Deliberately sending yourself into a condition which can cause hallucinations and physical collapse seems unlikely to be the best way to lose weight. DO NOT TRY THIS AT HOME I think should be added here!!
I also missed Mark Cavendish winning the Tour de France stage of the day because of my delay. (Amazing sports news, after only four days of the Tour de France we’ve had stages won by both French and British riders – I suppport both countries according to whim and neither happens very often. And there is even a glimmer of a possibility that David Millar will do pretty well over all. Hey I lived in Scotland for 2 years and my daughter was born there, I can support the Scots as well!)
Anyway today I might just stick with watching the race on the TV while eating a fistful of Mars bars. I recommend you do the same.
Putting aside the Mars bars – the Atkins diet (you know, the really trendy one “everyone” is doing at the moment) follows the same principle as your bonk exercise. From memory it is a totally carbohydrate free diet (and that includes no fruit) but NOT a fat free diet. The idea is that your body will use up the fat for energy when you exercise. A friend of mine was part of a team to walk to the North Pole – they ate a packet of butter, each, per day as their energy. I checked this out with a medic friend and he said that fat was a really good energy sauce. As a non-medic I can’t confirm this or otherwise but I’m sure there is a bit of truth in it.
On the subject of energy bars though I had a similar experience a couple of weeks ago in a tennis match. I was losing and tiring fast. I started drinking my energy drink in copious quantities and immediately felt more mentally alert. The physical side was still tired but I could organise my game better. Result…I won to my opponents total amazement! There is a period of time, in my view, between tiredness setting in and the ability to know what to do about it vanishing. If you can catch it in time you’re ok (probably) but if you don’t see it coming you’ve had it – hence the marathon runners ending up beside the road.
Funily enough Mrs B likes to do an hour of gardening before breakfast (before it gets too hot) and she tells me she has been losing weight, which might just be the same diet principle.
I think you are right about the timelag – I don’t know why it took me so long to remember I had an energy bar in the toolbag, think I was in a trance or something, perhaps not a very safe way to be cycling…
Interesting, Iv only started cycling in the summer, i row and that lasts only about 1 hour inside on a rowing machine or 1 hour 20 in a single scull on a long outing so ”the wall” was until this afternoon alien to me, not anymore. One hour thirty minutes into my ride, after only eating porridge and two dougnuts in the day and with no energy food on me im sure i hit the wall, all of a sudden bang! nothing in me. My heart rate dropped from 180 to 140 and i couldnt manage anymore than probably about 13mph on the slight incline i was going along, it was a nightmare i felt like i wouldnt make it, I looked at my HRM afterwords and it estimated around 1600 callories burned, so i guess i must have ‘bonked’. Next time il be sure to take some food with me, im sure that would have perked me up no end.
So Im glad i read this post il be sure to have an energy bar with me next time and it makes me feel much better about how pathetic the last half hour of my ride was today, thanks!