In Reply To:
Well, if you actually look at the latest research, there seems to be some evidence to suggest that training with in a slightly depleted glycogen state may lead to superior adaptations (do I have enough qualifiers in there?).
This is where some coaching pundits go from "you can't qualify methods based on results" to "I'll stick with what has been proven to work for elite athletes". Funny, that...
There's some stuff
here or
here if anyone's really interested, and you can read the referenced from the Tipton presentation if you're really bored.
As a lower volume guy, I think there's a lot of utility in 'training low' and 'competing high', as long as one doesn't over-do it, and I've had a lot of success with it.
That said, back to the OP: with regards to the comment about replenishing every calorie consumed, if I were exercising at an intensity that was burning 200 cal/hour, I probably wouldn't worry about consuming any gel. I'd worry about other things, like maybe training a little harder.......
Interesting points. To understand the concepts you mention about "train low compete high", or whatever the term used, requires a level of understanding more than just the concept that maximizing glycogen content during training/racing allows maximum perfromance. When considering the molecular responses to exercise of various forms within muscle and liver you can see that what you describe is indeed a possibity. Dr Coggan's comment is quite a slap in the face to a number of well respected, and very well published scientists as well. Being privvy to yet unpublished data on this topic in already endurance trained subjects, I can say it is quite interesting, and defintiely worthy of consideration.
There is mention of training with low glycogen being "catabolic" in this thread. Well, all training is catabolic. When we train, the cell signaling events within various tissues vary depending on the intensity, load, fuel content, many things. The activation/deactivation of various events is what drives the adaptations to training. What the most up to date research shows (not just the research in reference here, it takes more in depth reading than that) is that endurance training and resistance training, and the resulting adaptive signaling events cannot co-exist. The easiest way to understand this is that during metabolic stress induced by heavy prolonged exercise, growth/anabolic signaling processes are swtiched off. Sure, you need anabolic processes to recover from all training, but the primary performance-gaining adaptations to endurance training are gained partly through switching off the primary governing pathways of cellular growth.
Next, consider the way the adaptive signaling events are switched on by training. In simple terms, one of two ways: 1. Prolonged high intensity work, 2. prolonged lower intensity work with limited fuel. All your muscle cells see is the stress induced by these situations, and they adapt to it. That is what is important to getting better from training. Now, this doesn't mean it is a good idea to get around with an empty tank, as eventually this will become maladaptive, but you can certainly manipulate these factors to best work to your advantage. Eg, keep your fuels up most of the time, but do some training sessions while low on fuel to push along the traininng effect without the need to continually do very high intensity work. Strangely enough (or not) many top level ironman athletes do this anyway, whether actively trying to or not.
Also worthy of note: current thinking in some circles suggests you need all these carbs from training to encourage repair and protein synthesis afterwards (ie, eating carbs during, and carbs along with protein supplements after training). This is not necessarily the case - if you eat enough protein, extra carbs don't further enhance protein synthesis. Also, at least one study in a good journal (no ref at hand) suggests protein synthesis is enhanced at the end of a week of low carb diet, presumably as long as not in energy deficit. Obviously these are limmitiations and previso's here, but the bassic reasoning is sound.
Lastly, with respect to the main point in question in this thread, 2 gels/hr, every hr: This neglects one of the most important considerations for the endurance, particulaly ironman athlete - the need to train your liver. As soon as you consume carbs, particularly if immediately before exercise, you pretty much switch your liver to "off". In an ironman event, you most certainly want to keep your liver "on", and want to make sure it is trained to work at its max, just like your muscles. For our purposes, timing, amount and type of fuel is what controls this. Something to think about.
