1/2 Marathon Training – only 6 more days!

OK.  Less than 1 week to go.  Last weekend ran farthest ever AGAIN, 12.3 miles.  Ran a bit slower than I would have liked but the heat has been oppressive.  And I did not walk at all, just enough to drink a 20 oz Gatorade at about my 7 mile mark on our beautiful Chicago lake front.

Last long run this week.  Plan to run as close to 13 miles as I can with the focus of staying healthy and injury-free.  I still have to better pinpoint how much liquid and sodium I need over the race to feel good during and after the race.  This is still a problem I am having, particularly after a long run.

Here is what I have learned from our Gatorade scientists from the Gatorade Sports Science Institute (GSSI) in Barrington, IL.  To determine how much water you lose during a workout, you weigh yourself before and after.  That is your “sweat rate” and you can measure it in oz/hr.  Ideally you would want to be replenishing it during exercise but before works also; it all depends on you and your tummy.  

Here is an example using my sweat rate:  I weighed myself before and after an hour long cardio workout, I consumed 20 oz of Gatorade during my workout and I lost about 1 lb, or about 16 oz.  That meant that for that hour I exercised, I lost 36 oz. of water in my body. (Note – this figure may vary in a different environment so you should do this multiple times.) The Gatorade Sports Science Institute (GSSI) recommends replacing closer to 20 oz for every 16 oz or 1 lb lost – this is because we will probably lose some through urination after exercise and we want to account for enough fluid to replace all sweat losses.  Therefore, I should replenish that liquid afterwards at the very least so I am not dehydrated after the activity.

Another issue that endurance athletes (or people exercising for more than an hour) have is the risk of Hyponatremia, which refers to a lower-than-normal level of sodium in the blood. Sodium is essential for many body functions including the maintenance of fluid balance, regulation of blood pressure and normal function of the nervous system. Hyponatremia has sometimes been referred to as “water intoxication,” especially when it is due to the consumption of excess water, for example during strenuous exercise, without adequate replacement of sodium. 

So we have that going for us. 

According to MedicineNet.com, The National Athletic Trainers’ Association (NATA) recommends the following hydration guidelines for exercise:

  1. Two to three hours pre-exercise: 17 to 20 fluid ounces of water or sports drink.
  2. Ten to 20 minutes pre-exercise: 7 to 10 ounces of water or sports drink.
  3. During exercise: Fluid replacement should approximate sweat and urine losses and at least maintain hydration at less than 2% body weight reduction. This generally requires 7 to 10 ounces of water or sports drink every 10 to 20 minutes. Include carbohydrates in the beverage if the exercise is intense or lasts more then 45-50 minutes. Water alone will suffice, and save calories, if the exercise is moderate or less than 45-50 minutes.
  4. Post-exercise: Athletes should weigh themselves nude before and after workouts to learn how much weight is lost from sweat (water and salt) and then ingest fluid equal to 150% of the weight loss, ideally within two hours, and no more than four to six hours after the event. Including sodium in the drink allows fluid volume to be better conserved and increases the drive to drink, and carbohydrate in the drink will improve the rate of intestinal absorption of the fluid as well as replenish glycogen stores in the muscles and liver.

This is really enough to make my head spin.  Not that I can’t figure out how to solve the problem, it is really the physical logistics involved in ingesting that much at the proper intervals, while I am running 13.1 miles. 

And we haven’t even talked about carbs and energy yet.  NATA states to “include carbs…if exercise lasts more than 45-50 min”.  Definitely if you are exercising for more than an hour you need carbs.  GSSI recommends “up to 90 g” of carbs for every hour you are exercising.  Your body physically cannot store the carbs you need for a very long workout or activity, like, for example, a marathon.  Your body does have enough fat to last more than an Ironman competition that takes 10-14 hours (yes, even those with disgustingly low body fat). 

The key I am learning is the balance.  Per my GSSI scientist colleagues (go to their website to learn more, I am paraphrasing to explain things the way I understand them – http://www.gssiweb.com/), you don’t want to necessarily overload on fluid before as you might end up with GI (i.e., tummy) issues and/or uncomfortable sloshing.  Depending on the endurance activity (biking vs. running), you may be able to tolerate more pre-drinking before biking as you don’t have as much jostling as running.  An issue can be the urge to go to the bathroom during exercise based on when you had the pre-fluid.  If you are running a race, or if you have an aversion to port-a-potty’s (like me), you want to ensure this doesn’t happen.  Some recommended fixes are to drink closer to start time, or far enough before for the excess to make it through your system.  Adding electrolytes could help you retain more of the fluid and allow you to pre-drink a little excess. 

Then they told me, “The best thing to do is try it in training first.”. 

Hmm.  Sounds reasonable but I only have 6 days to go so I have one more time to try it out in training, then on to the real thing. 

So here is my plan:

I lose about 36 oz of fluid per hour and I plan to run the 1/2 marathon in about 130-140 mins, or 2 hrs and 10-20 min.  Therefore, I will lose 36 oz x 2.25 hrs = 81 oz total.  My plan is to have a 32oz Gatorade during the hour before the race.  That will give me 400 mg of sodium and about 53 g of carbs, (I will need at least that much every hour).  So, during the race, I will need about 49 more oz of fluid, which I really don’t know how to ingest.  I can pretty much get the carbs I need during the race with Gatorade chews (24g of carbs per pack of 4) but the liquid is the tough part for me.  At every station during the race, I will have to take 2 cups of Gatorade; I would guess there is about 4 oz in each of the cups they provide at races. 

I am also learning that thinking too much about the hydration and the especially logistics involved is not my thing.  In addition, all of this has to occur at 6:30AM, which is really not my thing.  Therefore, right now I am thinking this will be it, maybe one race a year, but nothing longer.  But we will see after Sunday!

The other part of my training was my “wine detox”, which, in full disclosure, I am not keeping up with (in particular last Sat.) but definitely have reduced my intake to assist in my hydration.  Will try to completely abstain this week.  Again, we will see.

Any other words of widsom from runners/athletes?  Of course, comments are welcomed from anyone, even couch potatoes.  After the race on Sunday, I will be joining you as I recover on my couch, very potato-like, watching TV with J and my dogs.  They probably won’t even notice I was gone, since I will be home by 9AM. 

Wish me luck!!!