Monday, August 5, 2013

Blood Sugar, Fatigue

Colle St Carlos

Yesterday was the first really big “climbing” ride of the year with 3100m accumulated climbing including the steep Colle St Carlos in Italy. The start of the workout was my “recovery” ride from last week’s race because I hadn’t been out once since. Despite resting for a week after cramping the legs enough to hurt the muscles for the next four days the legs were not responding to begin with so the first climb – 30k up to 2200m altitude from Bourg St Maurice to the Col de Petit St Bernard was just a warm up. It’s not like there was a choice. My heart rate stayed around 145bpm and the legs slowly got used to working again riding all the bad memories out and getting the blood flowing again.


The day was never going to be easy for a combination of reasons – lack of fitness, excess weight and slightly inappropriate gearing. My small chain wheel is 36T instead of 34T and being oval it’s equivalent to pushing a 38T on the down stroke. I’m about 10 kilos overweight just now and not working out nearly as much as I should. Part of the reason however for not training is the demotivating effect of tiredness. People talk about “doms” – delayed onset of muscle soreness – but strangely they don’t have an equivalent term for tiredness; for which I suggest – “dof” – delayed onset of fatigue.  A lot of people seem to get this, which renders them practically useless for the rest of the day after endurance exercise. Problems often begin during the exercise not just after. The first sign is a dull headache and then an inability to concentrate, a sort of “brain fade”; another of my personalised terms. Normally this leads to a plodding pace which could go on forever but which proceeds in a dense fog of negative thoughts and feelings. Sometimes there is no sign of fatigue during the workout, especially if it is short, but then an hour after completion you just fall asleep or become unable to concentrate of anything. There is almost a state of complete forgetfulness induced – as if you were drugged. This doesn’t seem to affect everyone the same way and is probably a result of differences in metabolism. There may also be psychological factors – not regarding the tiredness but regarding the stigma of discussing it. How can you possibly  be a “hard case” if you fall asleep systematically after your workouts? Better to call it a “nap” and pretend that it’s normal and a choice! Not so easy if you have a demanding intellectual program ahead of you though – like studying music or writing – which ends up being completely forgotten about.

The answer is too simple – food!

During yesterday’s monster session there was no headache, no brain fade, no stomach cramp, no fog of negativity and especially no “dof” – delayed onset of fatigue – despite the session involving 6 hours of intense heat in the sun and temporary cold in the wind at the high altitude mountain passes. After finishing at 7pm the rest of the evening until 2am was energised, not tired. What made the difference? The answer is too simple – food!
Exercise draws blood away from the gut and curbs your appetite. Add to this the difficulty of swallowing and breathing when running or cycling and cause of the situation regarding food begins to become more obvious. Once fatigue sets in and concentration becomes difficult then even the simple act of reaching for a gel in a pocket, opening it with your teeth and trying to swallow it seems like a strangely insurmountable task.  Gel is a pretty horrible goop at the best of times and humans don’t normally like things that resemble frog spawn so I have no idea why they add soluble fibre to make “gels”. Eating solid foods is even harder. The athlete tends to simply ignore the issue or delay eating as much as possible and keep it to a minimum. Often in a long workout only a few small gels are consumed. Adding powders to water bottles can be complicated and also drinking sticky water eventually becomes unpleasant. Gels and energy bars are stupidly expensive too – another reason to avoid them. Stuffing yourself with porridge and flapjacks just leads to a bloated gut and you can only really manage that a few hours before a session and not during it. So what’s the answer to all of this? Make your own energy supplements!
Perhaps after many years or a lifetime of training the body adapts to low sugar levels but for most mortals we don’t seem to have the means of getting to this point without sacrificing everything. It’s not even clear if such an adaptation actually takes place – but the body usually does adapt in positive ways to exercise. meanwhile the answer does appear to lie in food supplements and how they are delivered. Research appears to have converged on a certain formula of sugars – analysed for improving performance, but from my own brief experience giving a stunning solution to the “fatigue” problem. The problem is multifaceted in that it concerns:
  1. rate of absorption of carbohydrates from the gut
  2. quantity of absorption of carbohydrates from the gut
  3. metabolic processes
  4. ease of consumption
  5. motivation for consumption.
First of all here is the recipe: all ingredients can be bough online at 
Flexible flasks with nipples that can be opened and closed with the teeth can be bought from www.raidlight .com or other more compact reusable ones can be found at www.wiggle .com sold with supplements inside (squeezy lemon)

Per hour/flask:

  • 60 grams maltodextrin (High glycemic index 150)
  • 30 grams fructose (Low glycemic index 19)
  • 2 grams sea salt (Guerande – for quality)
  • 0.4 grams multivitamin/mineral (50% RDA – to be reduced if more than two flasks are to be consumed))
  • 0.2 grams caffeine (50% RDA – to be reduced if more than two flasks are to be consumed)
  • Lemon Juice to taste
  • Water – (total mix volume approx. 110ml) leave overnight to dissolve completely after stirring


Rate of absorption of carbohydrates from the gut

The two different sugars are absorbed in the gut through different pathways. It appears that Fructose is not completely understood in this respect. Maltodextrin is glucose molecules chained together. Both glucose and maltodextrin have the same rate of absorption (GI 150) but maltodextrin has one specific advantage – it requires only 1/6th of the water that glucose needs to be absorbed. This water requirement becomes critical when trying to avoid stomach bloating and pains during exercise. (Another name for glucose is dextrose.) The fructose (GI 19) is absorbed much more slowly.
Adding electrolytes to water causes the water to be absorbed more rapidly. Whether or not that causes the sugars to also be absorbed faster is not clear. What is clear is that you don’t want water bloating the gut for any reason. Electrolytes apparently won’t slow rate of absorption of carbs.

Quantity of absorption of carbohydrates from the gut

With the two sugar" digestion processes being different it allows the body to assimilate up to 90 grams of carbohydrates per hour total compared to the usual maximum of 60 grams. No doubt this also has an effect when smaller quantities are being consumed – simply being a more efficient absorption process.

Metabolic Processes

Maltodextrine (glucose) uses insulin when being metabolised. A rapid release of glucose into the blood will cause an insulin spike and then be followed by a blood sugar low due to excess insulin. One way to prevent the fluctuations in blood sugar is to keep up the intake of carbs every 20 minutes once you have started to use them. Fructose does not use insulin when being metabolised. Having a steady input of slower absorbed fructose should act to stabilise blood sugar levels regardless of what is going on with the glucose. Interestingly, when excess glucose is consumed it is converted into subcutaneous fat but fructose is converted into fat around the internal organs.No doubt that is why high fructose drinks such as sodas cause a big belly.

Ease of consumption

Gels are very expensive and difficult to use. Tubes end up thrown on the ground during sports events and anything that goes back into the pocket with an unsealed opening will make a seriously sticky  mess. Packets of gel are really difficult to open with the teeth and have to be consumed entirely. Food bars have similar issues – which could easily lead to loss of control of a bike at higher speeds or through hitting a pothole while attention is distracted. Gels can be horrible in the mouth due to their consistency and solid foods can seem to be too dry and difficult to chew and swallow. Reusable squeezy flasks are really easy to use and mess free. Bulk ingredients for supplements are cheap. Mixing with water only makes a runny liquid that is both compact and very easy to swallow in any desired quantity. When kept apart from drinking water the water bottles can be simply full of refreshing water. Each time you swallow some supplement you can take a drink of fresh water to clear the mouth and provide the water for digestion. Due to the maltodextrin there is no need to drink excessive amounts compared to when using glucose (dextrose). This makes the entire organisation simple and flexible. Even for those who have trouble drinking plain water (me) this issue is dealt with due to the sugar sill in the mouth.

Motivation for Consumption

When you know there is no expense, no difficulty, no mess and swallowing is easy then you feel encouraged to make the effort to consume the supplement according to protocol – that means “even without hunger or thirst”. You know that it will make life much better for you later on during the workout and in the recovery period. Flavouring can be added to taste with lemon juice being ideal but also freshly squeezed orange juice. Electrolytes can be altered to taste. Isostar provides 800mg of sodium per hour – which is the equivalent of 2 grams of sea salt. I use sea salt because it has no additives and still has its trace elements such as iodine, zinc, potassium and magnesium. This is quite a lot of salt replacement and so probably erring on the high side. It makes the supplement taste like toffee but doesn’t spoil the taste. If the weather is colder then clearly this can be lowered because there will be less sweating and water replacement needed – so as well as being able to adapt flavouring to your needs you can also modify the contents appropriately. This makes the whole system much friendlier, more relevant and more suitable.

Conclusion Regarding Food

Just a short spell with using this procedure has demonstrated a remarkable difference. Instead of being dominated by blood sugar induced fatigue during performance the limit is now simply fitness. After the race or training session there is a feeling of energising instead of the dreaded “dof” and consequent zombie act.

Cycling Technique

Chi-Cycling technique has now become the default coordination for me. In the past the monster Colle St Carlos circuit has always brought on some manifestation of sciatic issues for me – usually loss of feeling on the outside of my left foot – related to an old and failed lower back operation. Yesterday, despite forcing as hard a possible in sprints during the downhill sections in top gear and labouring on the steep St Carlos there were absolutely no issues with the back. This is clearly completely down to technique. The transfer of upper body weight over the pedal also removes all the weight from the other pedal automatically – so it’s easy to mistake the Chi coordination for a simple displacement of the upper body – but the motion is much more sophisticated and specifically involves the core muscles.


Climbing the steep St Carlos with gear ratios that were not big enough (for my weight) posed an interesting problem. It became clear that rather than resorting to inefficient weaving on the road it would be better to focus on more efficient pedalling. Correct coordination of the hips – pulling back the hip on the side where the foot is pushing forward at the start of the stroke (apparently moving the body over to that side) – made it possible to keep constant and smooth pressure on the pedals – one taking over immediately from the other. This smooth pressure would prevent little accelerations and decelerations – very critical to efficiency on a steep climb. The oval Rotor 36T chain wheel seemed to help organising this process a great deal – because the oval form causes a significant reduction in the size of the dead spot between each push. This is supposed to allow you to train the more appropriate muscle groups. It’s certainly easier using a 34T chain wheel but the oval 36T is probably much better than a standard 36T – even though it’s acting effectively as a 38T during the smooth and constant pushing.

The key to all of this appears to be “resonance”. It’s not about using force, it’s all about timing. Resonance is where the effect of a small impulse in a system is amplified – because it is in tune with the system. When effort is out of tune, even slightly, then most of the energy is simply absorbed and wasted. Instead of using force and strength it seems more important to be sensitive to tuning in to the system.  When the timing of the push (forward then down) is correct then it all connects up through the core muscles and there is a continuous muscle activity involving the whole body – especially the largest muscle groups. This allows a sort of overall relaxation instead of a fighting because there is no stress focusing on isolated muscles. There is a sort of relaxing spread of effort over all the muscle groups. If you watch the climbers in the Tour de France and in the time trials you see an enormous amount of body motion. People always criticise this but the best riders performing at their best do exactly this. This year on his historic victory on Mont Ventoux Chris Froome looked like a fish wiggling his way up there. They do not immobilise the body – especially the hips and pelvic area.

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