balancing nutrition and weight-loss

starting to run longer in training for half marathon

10 messages
13/07/2012 at 02:02


I'm trying to figure out my nutrition stategy for racing and training for a half marathon in Oct. Part of my reason for starting running was to lose weight. I have about 3 stone to go.

I'm now up to 14km with my long run, this Sunday. I'm slow, so this will take me close on 2 hours.I expect the race to take me about 2:45.

So far I've only taken water on runs, and then only one ones over about 40 mins.Do I need to start taking sports drinks and/or carbs with me on longer runs? I obviously don't want to consume so much energy it affects my chances of weight loss. But equally I don't want a lack of energy to slow me down, especially on race day.

I'd appreciate advice on getting the balance right.



13/07/2012 at 14:02

That's interesting, I would have thought it would be the opposite.

13/07/2012 at 14:20

good, interesting





Edited: 13/07/2012 at 14:21
13/07/2012 at 14:36

Any chance of linking to the article, or at least the studies/sources used?

13/07/2012 at 16:31

I'd be interested in reading that article too

There's an old saying that 'fat burns in carbohydrates flame' which basically means two things: if you have sufficient carb stores it permits you to exercise for a duration that encourages the metabolism of fat as a fuel source, and secondly that there are common metabolic pathways for fat and carbs, and depleting one somewhat disrupts the other. So, from a biochemical perspective, you do need to consume carbs to help with 'fat loss'. 

As for water not kick starting the process - I'm not quite sure what that's supposed to mean. Your body will metabolise stored fuel - be it glycogen, protein or fat - regardless of what you consume. Just consuming water during training will not prevent fat loss. 

Back to the original question though:

It's not so much the distance as the duration of your runs. If you're running over 90-120 minutes, you will start to deplete glycogen stores and this will have an effect on the amount of effort you can exert. Your power output will start to decrease, you'll start to feel fatigued and it will feel like a lot more effort to keep going. So taking on some carbs will help prevent this depletion and allow you to keep running. Personally, I'd say when it comes to race day - don't worry about the weight-loss aspect of your fitness plans. You want to do the race, and finish it comfortably. This isn't to say that you should take on huge amounts of carbs - one 500ml sports drink should be more than adequate for a half marathon if you're 'well-stocked' on carbs before hand. 

The key thing is to take what you need, and not to overcompensate before or after. When it comes to carb-loading - you don't need a huge portion of pasta, just a normal meal that's high in carbs. Post-race, eat and drink normally and try and avoid food-based rewards. 

Hope that helps!


Edited: 13/07/2012 at 16:31
13/07/2012 at 16:48

Yes, that's really useful, thanks.

I guess I need to practice with the drink I plan to use a couple of times on longer runs, just to check my stomach is ok with it. But this doesn't sound like it would be enough claories to upset the weight loss plans.

I'd been reading some things saying I should have a 100Kcal gel every half hour or so, which for a 3 hour run would be 600 cal. It seemed like a lot when I have much stored as fat already!

13/07/2012 at 17:07

But don't forget that you are going to be burning those 600 calories and more during the race!

I don't like gels very much, I've tried a lot of brands and they always make me feel a bit sick, ditto sports drinks. I do like Clif Shot Blocks - basically jelly sweets for athletes! - and those only have 33 calories per block. After the first 6 miles / 60 minutes, I take one block every half hour.

Just keep in mind that the Shot Blocks don't have electrolytes, so you need to find another way to replace lost salts (I usually have an electrolyte drink when I'm finished)

13/07/2012 at 19:57

Definitely a good point to remember that you are using those calories that you're replacing!

I'd say a gel every half hour for a half marathon is excessive. It's really unlikely that you'd actually need that - plenty of people do halfs on water alone. 

Whatever you choose to use - sports drink, gel, blocks/similar, just practice with it in training to make sure you don't get GI problems and remember that not all products are the same, so find the one that works for you/you like. And make sure you read the instructions on how to use the product - if it's gels/chews you usually need water as well. 

xine - I though Shot Bloks did contain electrolytes? 

14/07/2012 at 03:18

just to check my stomach is ok with it. But this doesn't sound like it would be enough claories to upset the weight loss plans.


16/07/2012 at 19:46

well i agree with all the previous comments...

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