I’m not a coach, I’m not a scientist … so I just get to disagree and explain it from my perspective from personal experience, some reading (not as much as James or John), and conversations. What made we want to write about this, these two recent posts:
So why do I disagree. Well I’ve only “bonked once” and that was on a Sunday recovery run after listening to Steve Sisson (who has since changed his mind about not taking any nutrition) and not taking a single Gu for 2 weeks but with not bonking I’ve consistently gotten fitter and faster, going from a 3:57 first marathon to a pr of 2:48 … so YOU CAN GET FASTER WITHOUT BONKING!
I read all this teach your body to burn fat stuff but any reading I’ve done on this brings up a couple of points consistently:
- fat is a plentiful store and we have lots of it compared to carbs
- fat per gram is around twice as much energy as carbs
- fat based energy processing occurs at lower intensities (50ish % of max heart rate) and takes more time
- your body can only become so efficient at fat burning, and it is good for lower intensities
So it’s those last bullets. Marathon goal pace is more in the 75-80% of max heart rate. So what the hell is fat burning going to do for me there. I can easily keep my body topped off with easy to process carbs with GUs in a marathon. But Kamran you’ll be better off making use of some fat stores too … ok whatever but if I can keep my glycogen stores up I will perform better than not doing it so why only take one GU in a marathon? And since your body can only really become so efficient at processing fat, and it’s really for lower intensities why should I train my body in that state? I don’t really want to enter a deficit and train for a deficit of energy for my marathon. I’m going to hydrate, take electrolytes and enough energy to be able to go as hard as I can for the entire 26.2 miles … carbs are the way to go for me.
Now I don’t want to discount everything John and James said but wanted to make the point strongly so people get a different perspective. I’ve been coached by Steve, who James cited, for a many years and that man (apart from being crazy) is an awesome coach. James used a quote from Steve: “The body can adapt to any stress if you give it enough time.” I completely agree with this, but I don’t think this means I should bonk by not taking any energy in during a workout. Running longer than you did the last time is stressing it, making sure you rest to give it enough time to take effect is adapting to the stress. To reach that breaking point both physically and mentally I like what Steve called Race Preps (well that was the p.c. name they used to be called Soul Busters), here’s my recap of one of those and below is an interview with Steve himself after one of them.
That type of workout is the toughest physical and mental challenge I’ve ever done. I took a GU like I was racing, one every 30 to 40 minutes but it didn’t matter, the workout stressed my body to the point where I just couldn’t handle it, being able to keep running was victory! You remember those workouts when you’re racing, you remember you were running half marathon pace on a 28 f$%king mile run … you can handle 4 more miles … suck it up. I don’t really want to remember “bonking”, I want to remember a damn tough workout where I mentally held it together.
So yeah during training you don’t have to Gu every 20 minutes but if you do, well you’re probably taking in more calories than you really need but let’s say you wait an hour and then every 45 minutes or so … that seems like a good idea to me. On a race day take GUs (plural), take electrolytes, drink water, drink Gatorade.
Did you see the Olympic marathoners this year? Did you see them picking up their specially made drinks with the right balance of electrolytes and energy? Well they seem to think it’s a good idea, and they make their living off of this, and I think they’re way way more efficient than me so why the hell would I not take multiple GUs in my race?
Lining up for their bottles at the Olympic Marathon