Last week, I attended the Marathon Nutrition Seminar at Milestone Running with guest speaker, Dr. Krista Austin. She’s an exercise physiologist and nutritionist, and has worked with some of the best American runners. The event was sponsored by Generation UCan, and everyone received a free sample for going.
Recently, I’ve been having digestive distress on and off, and I am also gearing up for my first marathon after years off from the distance later this year, so I’m obviously very interested in the topic.
One of the first topics covered was Race Weight. But I actually liked Dr. Austin’s definition: the lightest you can get, without sacrificing performance. Ideally, you’re maximizing your power:weight ratio, you should try to maximize power first, and minimize weight after, but not so much that you lose power, or hurt yourself. If you’re losing weight, aim to do so before training for your goal race, and if you find yourself impatient, you’re not eating enough.
Which brings us to nutrition periodization. You should plan your nutrition about a year out from your goal race. She touched on Macro, Meso, and Micro nutrition cycles, but didn’t go much into detail. I’m reading a review article, “Periodized Nutrition for Athletes,” by A.E. Jeukendrup to deep dive into the topic.
Dr. Austin did emphasize following a My Plate model (not necessarily counting calories or macros), and showed the below plate percentages depending on your day’s training.
She recommends the My Fitness Pal app for calorie tracking, and estimating your calories needed for daily life. Then to consume 1 g of carbs for every minute you spend exerting yourself in exercise (which is either zone 3-5 from your Garmin, or an Rating of Perceived Exertion of 5+).
For during exercise fuel, you don’t need to fuel less than 60 minutes of RPE 5+ (recovery intervals don’t count;) If you are exercising for more that 60 minutes take in:
- Moderate Exercise: 0.5-0.7g of carbs per minute (over 60min)
- Intense Exercise: 1g of carb per minute (over 60)
Fuel should be low glycemic index (no spike in blood sugar) and high osmolality (easily absorbed by the gut)
Other general guidelines:
- you should take in 20-25g of protein every 3 hours (and definitely within a few hours of a hard workout)
- you should drink 0.5oz of water per pound of body weight
- every pound you lose from exercise, you should consume 24oz of electrolyte drink
- If you have digestive distress, reduce your fiber to 10g/day for 3 days before (and including) race day
- Goal is stable blood glucose, you can lower the glycemic index of a high glycemic load food by consuming with protein
Keto & low carb came up briefly. She mentioned that if you feel good doing it, great. Do what works for you. Some athletes she works with get great results for body composition and lifting. However, she took the opportunity to reiterate that if you want to hit paces and push yourself in an endurance sport, you need the glycogen to support it. You can train to improve fat oxidation by training fasted, or on high fat/protein meal before running, but typically saves that for easy to easier days, nothing long or high intensity.
For race day, try something like UCan before the event, but after 45-60 min start taking in carbs. Whatever works for you. Practice well before your race so you can train low, and have time to practice your fuel. And practice carrying your fuel too. Us mortals aren’t as lucky as Meb to have bottles out on the course for us. Dr. Austin recommended taking whatever fuel you like with you on your run, and take water from the aid station.
There was nothing earth shattering in what she recommends, but it was a good review and reminder. Although sponsored by UCan, Dr. Austin wasn’t overly pushy or promising of the product, which was nice. I’ve tried it once, but am willing to try the free sample before making my personal judgement. The only thing that would have been nice, would be to discuss any differences between men & women’s fueling needs, but there’s not much research in the area, so I guess I understand. I am starting to train my gut, and practicing with different fuels before I start real marathon training late summer. I can’t wait to see what this training cycle will show with more emphasis on during exercise fuel, not just lifestyle fueling.