Fluid Replacement Drinks??? (Read 1058 times)

They have. It's called a hash run.

When you run, you need carbs

I once wrote this, feel free to debate. I think it is related - Your body contains about 2000 kcal of energy stored as glycogen. and another 4000 kcal for EVERY pound of fat you have (e.g., a 150 lb person with just a 5% body fat will still have almost 8 lbs of fat, worth about 32 000 kcal!). Energy expenditure while running is a function of your weight, and to a lesser extent the grade of the road, and to a far far lesser extent to your pace. So an 8 m/m runner is burning energy at about the same rate PER MILE as a 12 m/m runner with the same weight while they are both running. A 150 lb runner will burn approximately 120 kcal per mile run. Your body uses two fuel sources to run. One is glycogen. Glycogen is the primary energy source used for fight or flight type activites, which means it is the primary energy source used when running. When you run above 80-90% of your maximum effort (or VO2max, or Maximum HR), your body is burning almost entirely glycogen to fuel the effort. Below that, your body starts using the other energy source, which is fat. An innacurate but useful rule of thumb is that your body fuels its effort using glycogen as a percentage of total calories used that is equivalent to your perent effort. So if you are running at a 70% effort, about 70% of the kcal you are using to fuel the effort are coming from glycogen, and the rest come from fat. The reason you bonk is that you run out of glycogen. If you weigh 150 lbs and are running 80% effort, you will use about 2000 kcal worth of glycogen in about 21 miles. If you are running at a 70% effort, it will take you 24 miles to use 2000 kcal worth of glycogen. So why do you bonk at mile 18? Well, even if you carb load absolutely perfectly (and most of us do not), when you finish loading, you then go to bed and sleep. When you wake up marathon morning, your body has used up as much as 25-30% of your glycogen just keeping you alive overnight. And the next morning, the little bit you are able to force down into your stomach, well it does not ever get a chance to be stored as glycogen. Calories on the course? Sure, there are two general options. There are sports drinks, which deliver 4-10 kcal per cup, depending on how dilute the mix and how full the cup. And there are gu or jelly bean packets, which deliver about 100 kcal per packet, provided you can get every last bit. It takes about 1 1/2 packets of gu or about 15 cups of sports drink to fuel each additional mile (i.e., spare your body's need to burn glycogen) When you bonk, you slow down. When you slow down, your body preferentially burns fat. That is how you can finish, even after bonking. So, putting it all together, assuming that you weigh 150 lbs (thereby burning 120 kcal per mile), that you are running your marathon at 75% effort, and that you are able to store 2000 kcal, but that you also slept during the night and burned 25% of those calories, but that you take enough gu and sports drink to get 2 extra miles: ((2 000 kcal glycogen * (1 - 0.25 burned last night)) / (120 kcal per mile * .75 effort)) + 2 miles from carbs on the course = 18.6 miles You will bonk at mile 18.6. Or so. It is never quite this predictable. You can also attenuate this by long-term training (which increases your total body glycogen storage abilities and improves your fat burning at high exertion over time).

What do you brew? I have been brewing for about 15 years. Whole grain, of course. It is a great outlet!

Trent, you say that runners need simple carbs. Would I be better off eating white bread/rice etc than the soy & linseed bread/black rice that I currently consume? Also I am vegetarian (have been for 20 years) and I am wondering if that will become an issue as I run longer distances. I eat a lot of tofu, nuts, cheese, bananas, eggs - but is that goung to be good enough if I am in this for the long haul? Claire xxx

They have. It's called a hash run.

on-on! There is a lot of discussion here about different solutions. I don't pretend to understand the science, but I do understand that getting protien after a long run is important. I have tried several different post-race recovery drinks and choclate milk is one of my favorites. I have specific experience with a product called Recoverite (e-lytes, carbs and protien), made by Hammer Nutrition and, in my experience, I have a lower level of muscle soreness the first 2 days after a long run and believe this helps me get back to running sooner after the long run/race. Lynn B

I don't think there's anything better tasting after a hard workout than a cold beer. Plus the carbs are great for replacing muscle glycogen, and dark beers like Guinness are loaded with antioxidants known as flavonoids. The alcohol also has anti-clotting effects. http://news.bbc.co.uk/2/hi/health/3266819.stm http://www.instapundit.com/archives/014995.php

There's beer and chili at the end of the Grand Rapids Marathon. I'm not sure if it's always from the same brewery, but this year it came from New Holland Brewing Co.. Hit the spot after my HM. I also heard rumors that there was a beer station near the end of the full marathon...which is why GR will hopefully be my first marathon in a few years.... k

I often run up to 20 miles in the Winter without taking fluids. You do not want to get more than about 5-10% dehydrated, max. Percent dehydration is defined as the percentage of your body fluids that you have lost due to sweat or other means. Of your normal weight, fluids make up about 60%. So, if you weigh 155 lbs, you normally have about 93 lbs of fluid, or 42 kg of fluid. 42 kg is the same as 42 liters. So, 10% dehydrated is about 4 liters (or 1 1/2 gallons) of fluid. To figure out how much you need to drink, you need to determine your sweat rate. Sweat rate varies based on ambient temperature and humidity, and everybody sweats differently. The best way to figure this out is to get naked, weigh yourself, go run for 30-60 minutes, then get naked again (unless you ran naked) and weigh yourself again. The difference in your weight in kg is the amount you sweat in liters. So if you run an hour and weigh 4 1/2 lbs less afterwards, you have lost 2 liters. If you sweat that much, you need to drink about 2 liters every hour of running. BTW, most folks will not sweat that much. Your sweat rate calculation also only works when running under similar conditions (i.e., you cannot use a winter sweat rate for summer fluid prediction). That said, a better way is simply to monitor how you feel and your urine. When you finish a good run, you should be able to make medium dark to light urine within an hour. If you cannot or it is too dark, you need more to drink. If your urine is frequent and crystal clear, colorless, you are drinking too much. If you need fluids and don't want to lug them around, you can stowe them on your route, or run shorter loops and keep them in your car or house.