Hydration

Hot and sweaty post ride look. Got to love the Florida heat...NOT!

The heat and humidity of the Florida summer is in high gear. Rides are substantially harder now due to the drastic fluid loss one experiences when riding. For example, I loose between 5 to 7 pounds on my standard 30 mile ride. Hydration more than ever takes precedence this time of year, so it’s time to refresh some basics of hydration while cycling.

Back in the 1960’s, it was common for riders in races like the Tour de France to stop off at roadside bars for a glass of wine or something stronger. This seems hardly believable now, but there were some extremely long marathon stages in those days, and a more laid-back attitude prevailed, at least in the early part of a long hot day.

Sports science hardly existed back then. Today, there is much better understanding of proper nutrition and, specifically, proper hydration, which is vital for cyclists at all levels, especially if you will be riding for more than a couple of hours, even at a moderate pace. Dehydration can have all sorts of unpleasant consequences. Cramping is the most obvious, and real heat exhaustion can follow, which can even be life-threatening. Dehydration can impair concentration or judgement, which could also be life-threatening while riding in traffic or off on some trails. Low-level, sub-critical dehydration may have no obvious symptoms, but still makes riding less comfortable, less efficient and less pleasurable. If you tend to gulp down several glasses of water or soft drinks at the end of a ride, you’ve probably reached this point.

So what should you drink?
Plain water is good, up to a point. It’s certainly loads better than nothing. When exercising you lose fluid partly through breathing and partly through sweating. What you breathe out is mostly water vapor but sweat contains electrolytes, which also need to be replaced. The more you sweat, the greater the electrolyte loss. This is where special electrolyte drinks/sports drinks come in; they are designed to match the chemical balance of what you lose. Soft drinks are usually loaded with sugar, something you don’t need so urgently for most rides, and generally do little to replenish electrolyte levels. Some “energy” drinks also contain caffeine. Caffeine is a diuretic, making you pee, which doesn’t help hydration either.

Curiously, it is possible to drink too much water. We lose salt plus water in our sweat. If you do long workouts or races there is a danger in replacing these losses with just water. You can develop a condition called hyponatremia which means the body has a diminished salt concentration in the body fluid. It is hard to believe but athletes can actually die from consuming too much water.

When to drink.
You can begin to dehydrate before you feel thirsty. The single most important rule of hydration is: Drink before you think you need it.

How much should I drink?
There is no exact answer to this question. It depends on body mass, metabolic rate, how hard you are working, how hot and/or humid it is, how prone to sweating you are and so on. The common figure used for hydration is one litre per hour, which sounds like a lot, but it is probably a realistic figure for cyclists as well as other endurance activities, but may be on the high side for those riding recreationally.

In general think 1 bottle per hour. On extended rides over 2 hours, be sure to use a sports drink to replenish lost electrolytes and avoid hyponatremia.

A good rule of thumb is:

1. Use a sports drink like Powerade or Gatorade since they provide you with the sodium and potassium that you lose in sweat. They also provide carbohydrate (sugars) which gives your muscle the fuel they needs to function. Do not make the mistake of diluting a sports drink to make it last longer. These drinks are formulated to provide you with the right amount of fuel and minerals, which is typically around 6% carbohydrate, at least 100mg sodium and 35mg potassium per 8 ounces.
2. For rides lasting over an hour or very hot conditions use a sports drink not plain water.
3. Before a long training ride or race, drink 17-20 ounces of water or sports drink 2 to 3 hours before the event. Then another 10-12 ounces 10 minutes or so before the event. During the event drink a sports drink at a rate that replaces your sweat losses.
4. After the ride or event, be sure to replace your fluid losses with a sport drink within 2 hours.
5. A lot of fluid is lost through breathing, so even though it may not look like you are sweating much you are still losing fluids.

How can you tell you are drinking enough?
1. Feeling thirsty. Yes, this is obvious, but you need to remember that you can be in early stages of dehydration before you have any sensation of thirst. A raging thirst after a ride is a sure sign of under-hydration. If the ride is only an hour or so then this is unlikely to be dangerous, but it’s still better to forestall it. Waking up with a ‘hangover’ the next morning is also a sign that you haven’t taken on enough liquid during the ride.
2. The “pee test”. If you feel the need to urinate at about the same interval when riding as you do when not exercising, you’re probably adequately hydrated. If the intervals get longer and longer, or the volume is reduced, you should increase your fluid intake. And if your pee is significantly darker in colour than normal, this is a real warning sign.
3. Headache, dizziness, “hungover” feeling. All are likely symptoms of dehydration.

Remember to always map your training routes, particularly longer ones around your hydration needs. You can typically carry 2 water bottles on your frame or behind your seat, or you can use CamelBak type products to carry even more liquids. I always carry 2 bottles, one with water, the other typically with Powerade. I also make it a point to know where I can get quick water refills on my routes. Dehydration leads to very serious problems, so always plan ahead.

Today’s sweat soaked ride was down Treeline again. Although only 30 miles, the extreme heat, high humidity and hot wind had me gulping down 4 bottles on the ride. I think it may be time to alter my schedule a bit and start the rides around 6AM to help beat the heat.

Finished Cycle: Jun 15, 2011 11:28:42 AM
Route: Treeline
Ride Time: 2:05:49
Stopped Time: 41:39
Distance: 29.87 miles
Average: 14.25 miles/h
Fastest Speed: 21.88 miles/h
Ascent: 157 feet
Descent: 82 feet
Calories: 1969

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