Staying Hydrated With Logan-Sprenger

Posted on 27. Apr, 2011 by in interviews, race

At the Redlands Bicycle Classic where the temperatures hovered in the high 90s under cloudless sunny days, staying hydrated became even more important for the racers. For most, it was the first hot spell of the year and the heat took a toll, some suffered from muscle cramps that forced to stop and drink during the second stage.

What should a racer do in those conditions? “Drink a lot and make sure you start the exercise hydrated because typically 50 percent of athletes start exercising already dehydrated and it just exasperates any physiological responses.” replied Heather Logan-Sprenger of Colavita Forno d’Asolo.

Make that Dr Logan-Sprenger. The 29-year old Canadian has just successfully defended her PhD in exercise physiology and metabolism and nutrition. She had a research grant from the Gatorade Sports Science Institute to look at the effects of dehydration on muscle metabolism and tissue damage performance.

Her team is benefiting from her knowledge. “We did some sweat testing with our team at team camp just to see the sweat rates of certain athletes and I gave them some recommendation on how much they should be drinking every hour to maintain their fluid balance so, just every time you have an opportunity to grab a bottle and drink, drink.”

Heather Logan-Sprenger (Colavita Forno d'Asolo) stayed hydrated in the Redlands heat

Heather Logan-Sprenger (Colavita Forno d'Asolo) stayed hydrated in the Redlands heat

And it’s not just the cyclists that have to worry about dehydration as yours truly found out the hard way. The first day was a short prologue of around 15 minutes for the riders. But with huge fields, the first day called for straight 6 hours of shooting, in the sun with no shade with heat radiating up from the road. The next day was another hot one another 5 hours in the sun. While I remembered to drink, it was water and simply said my body rebelled, that night after the second stage, chills, fever and ‘stomach issues’. Yep dehydration. Everything only got back to normal two days after the race.

And that’s where mixes come in to play as Logan-Sprenger explained. “Mixes are key because they not only provide you with water that you’re losing in sweat but it gives you the sodium that you’re losing which helps with muscle cramping and then you get the glucose, the carbohydrates that you need.”

Cramping can also result from dehydration. “Sodium is the major ion lost in sweat, that’s a huge electrolyte, that’s been shown to cause muscle cramping. If you’re losing a lot of water and a lot of sodium then it contributes to muscle cramping.”

Part of Logan-Sprenger’s research was done through exercise trials on athletes. “Taking muscle biopsies and seeing carbohydrate use is increased when you’re dehydrated and the effects of what kind of fuel you are using when you’re dehydrated and when you’re hydrated. It’s significant typically, especially for women they use a lot more carbohydrate during exercise even if they’re only 1 or 2 percent dehydrated which can happen after an hour of exercise.”

Dehydration can also be an issue at high altitude like Tour of the Gila

Dehydration can also be an issue at high altitude like Tour of the Gila

Dehydration is another challenge at the Tour of the Gila along with the climbing and wind. While the temperatures are forecasted to stick around the 70s or low 80s, altitude comes into play.

“At 6000 ft above sea level, you exhale and perspire twice as much moisture as you do at sea level. Over the course of a day, that is a lot of water, and can make a difference of a quart or more a day. At higher altitudes, it gets even more pronounced. This is when sweat loss from exercise is not accounted for. Ultimately, higher altitude means lower air pressure. This results in more rapid evaporation of moisture from skin surface, and from your lungs. Most high altitude areas are also very low in humidity, which means evaporation is further accelerated.”

So as a result, a racer must drink more than they are used to and more frequently. “It is important to ensure you begin a race well hydrated and during the race think to drink prior to feeling thirsty. Drink, drink, drink, is the recommendation. Unacclimated athletes will sweat less and have a higher risk of over-heating, so it is recommended to drink ~150-250 mL of fluid every 15 min during exercise.”

The impact of dehydration can be felt relatively quickly. “If an athlete lets themselves get dehydrated by ~2% body mass loss, which may happen within 40-60 minutes of intense exercise when fluid intake does not match sweat loss, they will experience exasperated physiological responses (higher heart rate, core temperature, and rating of perceived exertion) compared to exercising at the same relative intensity when hydrated. Inevitably, this will lead to premature fatigue and may potentially be the difference between a podium performance and a field finish.”

So as Logan-Sprenger said drink, drink, drink and drink some more.

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One Response to “Staying Hydrated With Logan-Sprenger”

  1. Name Carolyn Logan

    27. Apr, 2011

    Great work – Loooved the photos!!! Love Marm xo