Most studies of marathon runners have shown that training the body to utilize fat as the primary fuel source for as long into the race as possible is optimum for avoiding "the wall". The longer your body can burn fat, the longer it can put off burning carbohydrates, and thus the longer you last before glycogen depletion cramps your style (literally). This is accomplished two ways: high volume of training at the edge of your fat-burning zone, and the strategic intake of carbohydrates during training runs. This article gives great perspective and research on this topic.
Many of us are early morning runners, be it by necessity or preference. Unless you are getting up around 4am to eat a meal before your run, you start your run on an empty tank. This isn't too big of a deal for runs less than 45 minutes, or maybe a little longer at low intensity. We certainly have plenty of reserves for such runs, and are staying in the fat-burning zone anyways. But for longer runs or high-intensity training, some pre-run fuel is necessary to attain optimum training performance. Without it, you don't hit your goal paces and won't see the progress in your training that you need for optimum race performance.
The key is to hit the perfect balance of fat utilization training and sustaining goal pace intensities during hard workouts. In Matt Fitzgerald's most recent book on nutrition, he outlines a plan for achieving this balance in what he calls "hi / low" nutrition training, fueling during some runs and fasting during others.
Here is my plan based off of his philosophies, and examples of fuel:
Carbohydrate consumption:
Many of us are early morning runners, be it by necessity or preference. Unless you are getting up around 4am to eat a meal before your run, you start your run on an empty tank. This isn't too big of a deal for runs less than 45 minutes, or maybe a little longer at low intensity. We certainly have plenty of reserves for such runs, and are staying in the fat-burning zone anyways. But for longer runs or high-intensity training, some pre-run fuel is necessary to attain optimum training performance. Without it, you don't hit your goal paces and won't see the progress in your training that you need for optimum race performance.
The key is to hit the perfect balance of fat utilization training and sustaining goal pace intensities during hard workouts. In Matt Fitzgerald's most recent book on nutrition, he outlines a plan for achieving this balance in what he calls "hi / low" nutrition training, fueling during some runs and fasting during others.
Here is my plan based off of his philosophies, and examples of fuel:
Carbohydrate consumption:
- 45-60 min easy runs - no carbs
- 45-60 min hard workouts - 30 g / hour (one GU + 8-10 oz of sports drink, or 1/2 a bag of GU chomps)
- 1-2 hour easy runs - 30 g / hour on half of all type (same as above)
- Races or hard runs longer than 2 hours - 60 g / hour (two GU + a bag of GU chomps or 10-16 oz sports drink)