Preparing to Run a Hot Weather Marathon

This weekend is our local club goal race, the Bayshore Marathon/Half Marathon  in Traverse City. Everyone is suffering through the anxieties and aches and pains that pop up during taper. Some are worrying over whether their little niggling injuries are going to keep them from reaching their goals. Others are studying their training logs to reassure themselves that they are well prepared. The newest worry that has popped up on everyone's radar is the weather.

This past weekend in Michigan was the warmest one this year. It hit the 80s yesterday, and that made everyone a bit uneasy about next weekend. I am not immune to this worry and have been to weather.com twice already today to see what they are predicting for next Saturday's race. Right now, the forecast is perfect (51 at start/71 as a the high). However, what is bothering everyone is that the days on both sides of that are 50/82 and 62/91! Not exactly ideal racing conditions.

This has everyone wondering what to do if the weather heats up on race day. The truth is that there is not a lot that can be done beyond adjusting one's expectations some. Everyone will be a little (to a lot) slower if the weather gets too hot. Still, there are some little "tricks" that one can use to help make running in the heat the best experience it can be.

1. If you expect it to be hot on race day, start early to acclimate. This one is tricky because it needs to be started about two weeks out from the race. A lot of runners go to great lengths not to run when it is too warm out,  but running always when the temperatures are ideal does not prepare you for a hotter race on race day. There are physiological changes that can occur that can help you run better in the heat, including increased plasma volume, decrease in heart rate,  decreases in sweat sodium, etc. The following table shows some of the adaptations that occur and the days of acclimatization at which these occur:

(from Henderson, Bill "Heat Acclimation for Runners") 

2. Hydrate well in the week before the race: One thing you want to be sure of is that you are fully hydrated on race day. Many runners are chronically dehydrated. You want to be sure that you are getting enough fluid, but you also want to be sure that you are getting corresponding electrolytes. Drinking large quantities of water the week before a race can wash valuable electrolytes out of your system. Be sure to include sports drinks with electrolytes in your pre-race hydration strategy. If you are worried about calories, use a 0 or lo-cal option rather than the full sugar versions. I use Power Ade Zero for my prerace hydration.

3. Salt your food the week before a race: Generally most Americans need to watch their salt intake. However, in the days before a planned marathon in hot weather, adding a little extra salt to one's meals can help assure that you have enough sodium in your system to help cover losses from excessive sweating on race day.

That covers what one can do before the race to prepare. There are also a few things to remember and a few tricks for race day itself:

4. Dress for the finish, not the start: This one is hard for me. I don't like to be cold, and 50 degrees is cold for me. However, dressing to be comfortable at the start of the race means that you will be uncomfortable when the temperatures start to rise. One piece of gear that I find invaluable these days are a pair of lightweight sleeves that one can put on and easily slide off when it warms up, such as these by Pearl Izumi . I used those effectively in my last ultra, and it was great to be able to slip them off, tuck them away, and forget about them. If you do need to cover up at the start, be sure you are layered so that you can remove the layers as the day heats up.

5. Stay out of the sun whenever possible: As the day starts to heat up, be aware of where you are running. I have seen runners suffer unnecessarily by running down the middle of the road in the sun when there was shade along the street closer to the curb. Be aware of your surroundings and run in the shade whenever you can.

6.  Stay hydrated: I know, I know -- you have heard this before, but let me see if I can give you some information that helps you rethink this. First of all, studies have shown that runners, even "seasoned runners," horribly underestimate the fluid that is needed during a race. In the article "Runners Underestimate Fluid Needs," the author reports a study  that found that "runners underestimated their sweat losses by an average of 46 percent and their fluid intake by an average of 15 percent, resulting in the runners replacing only 30 percent of their fluids lost through sweat."  She makes the following statement that should make us all stop and think: "If seasoned athletes such as these do such a poor job of judging their fluid needs, the potential for dehydration may be more severe for the average exerciser, especially during the hot summer months."  The author recommends drinking on schedule every 15 minutes during the activity.

The second thing to consider on race day is how much you are drinking. Many people actually do a better job of hydrating in training than at a race, despite there generally being more aid stations, because during training most of us take time to fully hydrate at the stops.

However, in a race two things happen. First we are in a hurry so often don't take time to get a lot of fluid in. Second, there is an issue with the cups at races and the volume of fluid in them. Most of the cups that are at the races are 8 oz cups. Those cups are often filled half full or less. How many times have we taken a cup at an aid station to find that it was less than half full? Now subtract from that the amount that is spilled from not slowing down enough to get the fluid in (I can't be the only one that does this!). At some stations, even drinking 2 cups may not get you a full 8 oz. of fluid.

A person can't just think "I drank two cups at the last aid station," and call it 16 oz. Pay attention to how many actual ounces you are consuming and make sure it is the amount that is on your plan. Also, it is now recommended by U.S.A. Track andField that runners use sports drinks, rather than water, to hydrate in hot weather. According to their press release "a sports drink with sodium and other electrolytes is preferred."  This is to avoid hyponatremia from taking in too much water and washing electrolytes out of your system.

7. Consider electrolyte tabs: This is something many road marathoners don't know much about, but which most ultrarunners swear by. When I am exerting in the heat, I sweat profusely. I lose a lot of electrolytes, and I sometimes have calf cramps at the end of races that remind me about the lost electrolytes. I do take in electrolytes in the sports drinks, but cannot get enough to compensate for my losses.

When I am running longer than an hour and a half in the summer, I take electrolyte caps, one per hour, both in training and especially in racing. There are several brands, such as Endurolytes and Succeed S Caps , both of which I have used successfully. There are also electrolyte fizz tabs, such as Endurolytes Fizz that can be put into a water bottle (which I have not tried).  If you have not tried an electrolyte replacement of some type for hot weather, you may want to. However, you know the advice: Don't try anything new on marathon day.

8. If it gets really warm, douse with water whenever possible: Arthur Lydiard, the great New Zealand distance running coach, used to have his marathon runners carry a sponge in their hands to wet themselves down in hot weather. While most of us are not likely to want to run with a sponge. Pouring a cup of water over the head can cool one off during a marathon, as can dousing one's shirt or top (just be sure that late in the marathon, when your thinking is getting fuzzy that you repeat the mantra "Water on -- Gatorade in" and not the other way around!).

These are some tips to help you cope if the weather turns warm on marathon day. While we all know that "you can't fight Mother Nature," but with this information maybe you can survive a hot race a little more comfortably.

Related Posts:

Running in the Heat: Adjusting Your Pace