This post is in response to the below question I received from an Athlete recently after a string of hot races here in Ontario.
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Hey Peter
You have likely seen Joe Friel's latest blog about drinking water
already but its funny it came up as I had been thinking about a similar topic after the last 2 races were so hot!
http://www2.trainingbible.com/joesblog/blog.html
I almost feel as if I drank too much water before the last 2 races, which were very hot and due to this may have diluted my electrolytes (to put it simply).
I was just wondering if you had any thoughts on optimal fluid intake both during and before events that would prevent excessive hydration ?? It is obviously a complex and personal thing but I would think there is some way to avoid over drinking but still be preparing for hot races properly?
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Great Question
In general I would say most endurance athletes get in trouble before races, rather than in training and normal life, because they start drinking constantly due to nerves and apply the standard "more is better" philosophy that seems to be associated with everything endurance athletes do! (Pre-race pasta meal, 7hr rides etc.) That said, if you did do this it is unlikely you experienced a tremendous negative effect unless you really overdid the water consumption before and drank straight water during the event in great amounts (28+oz/hr). Also most of the severe incidents of hyponatremia occur in longer events like running marathons and Ironman. Nonetheless, it is possible you are losing some performance through over-hydration so lets take a look.
Short Answer
What I do is drink the same as I do on any other day. This is easy to say once you have established what you need for a normal day but my first advice would be to 1) listen to your body and feelings of thirst and 2) monitor urine color is not dark yellow or perfectly clear 3) use a scale (best with body comp / BIA scale) to monitor changes in body weight/body water. For any race try to consume an extra bottle in the morning of a race, unless its really hot and then consume 1-2 more to satisfy thirst and expected demand (usually no more than 3-4 the morning of the race). I always pre-plan my drinking on and off the bike to ensure my nerves do not drive me to overconsumption and finally I use endurolytes for 1-3 days prior in all drinking water / tea to enhance absorption and perhaps protect against this dilution effect.
Longer Answer.
One statement that has always stuck with me on this topic is from Noakes, who is one of the leading experts in hydration. He said, loosely, that front-runners typically tend to dehydrate, while over-hydration occurs most often among middle to back-of-the-pack athletes. So while a top runner and a novice would both experience hyponatremia the athletes at the front of the race are capable of dealing with moderate (1-5% BW)fluid loss, mostly because they are starting the race with an optimal electrolyte balance (amount of minerals, like sodium/calcium, relative to water in the body's cell). The athlete who consumes too much water is out of electrolyte balance before they start usually and further dilutes their cells as they over consume water during the event.
They risk muscle cramps (just like in severe dehydration) but also stomach cramps, bloating, and excessive urine output. All of these symptoms quickly and severely throws the athlete's electrolytes even more out of balance and can start to impair cognitive and muscular function.
So how do you avoid over-hydration ??? Much of the research that is found
focuses on hydration during endurance events. This is where the top riders would
consume less then the riders at the back and middle. This may be related to time
and speed of their race but also comes into planning (last post on time in transition/feed stations relevant here). Both athletes would do well to stay on the lower end of current ACSM recommendations 400-700ml/hr (15-25oz). The lower end of the range would apply to smaller athletes and workouts/races with less external heat stress while the top end for severe heat. Additionally, this should be consumed as a sports drink with sodium/electrolyte content (ie. Hammer Endurolytes) Using more sodium or electrolytes as heat stress and water intake increases is also a good idea. Establishing your optimal amount of electrolytes to replace is related to your sweat rate/composition and again takes some time to optimize but starting with a moderate amount as found in most sports drinks and adding/diluting as necessary is likely the best way to move forward.
- Optimally you will be able to finish a ride / race and not lose more than 2% of your bodyweight (performance loss occurs around this point). If you find you are over this then more fluid needs to be consumed during your future workouts. Try to listen attentively to your desire to drink as once you are tuned into this it is likely your best indication of daily and workout hydration strategy.
- If you are gaining weight over a workout you are over-drinking and should reduce this during your future workouts. Over-drinking is usually accompanied by a feeling of 'sloshing' in the stomach.
- Replace each LB of lost weight with about 500ml/16oz of water over the few hours after the workout
More relevant to your thoughts, however, is drinking strategy before an event. I really like to keep things similar to any other day of training. Aiming for around 16-20 oz in the 2-3 hrs prior to the start may be a good place to start in terms of additional 'pre-drinking' for an event. While 8 glasses a day may be a bit ambiguous and way off for people who vary from the average by too much, I think starting with a set goal of water consumption is a good idea. Use your training log/diary to record how you feel, how often you need to go to the bathroom and adjust from there.
From there consider the following:
- If you have a Body Composition Scale (BIA) body water % should be in the 60-70%+ range (females usually 60-65%, and males slightly higher, both ranges assuming person is not carrying much excessive body fat). Working to normalize this % and body fat % over time is a positive health goal and should help better handle slight dehydration and heat stress as well. Additionally, this type of scale will help you monitor your daily body water % and whether you were a bit under hydrated the day prior (day after a hot race I am usually down a few %)
- Leading up to a hot race there can be some 'loading' effect from SLIGHT increases
above typical water consumption, but remember to offset this with a bit of salt or electrolyte powder.
- If you absolutely need a quick way to calculate a staring point for your daily consumption (consumption during workouts on top of this) I have seen some research around .5 OZ / LB of bodyweight. Interestingly this puts anyone over ~135lbs over the 8x8 ounces a day guideline, but does personalize the recommendation at least. As Joe points out, coffee and other drinks should likely be included in this and increasing veggie/fruit intake will also help maintain daily water requirements.
- If you have established the amount of water you consume on a regular training day then I would suggest looking at using a strategy of taking in 2-3 regular sized bottles the morning of the race and adjusting as you gain experience. Note that planning and recording how much you will drink rather than leaving it up to your nerves is a good strategy. This morning consumption should be accompanied with electrolytes as well to maintain electrolyte balance.
- It is good practice to avoid adding salt to meals most days for enhanced health but the day or 2 prior to the race a bit of salt on your meals and in your water may help enhance storage and reduce the chance of hyponatremia so enjoy the treat of the extra flavor!
Hope that helps anyone who is wondering ... post to comments if you have questions/comments or your own situation!
