Racing Dehydrated/Lighter

This entry was posted in Comments about Cycling on by .

I am finally reading my emails and got one last night from my friend, Jimmy Mac, that had a link to a Cyclingnews article.  The article was on “functional dehydration” relating to Chris Froome’s ability to climb faster at the Tour de France.  Jimmy Mac said I did an interview with him at Mountain Bike Action, over 10 years ago, with me saying the same thing.  I don’t remember that interview, but I’ve always had that view.

I think it is a personal thing how much water you need to consume while riding, or racing. Some guys need to drink constantly, others hardly at all.   I’ve read a bunch of articles stating how quickly an athlete’s performance declines with a small amount of dehydration.  I don’t have that problem.

Here is my example.  I raced the Pro Road Championships in Philadelphia multiple times.   The race was always in June and many times the temperature and humidity were close to awful.

One year, we were staying at a nice hotel, pretty much on the course.  The hotel had a scale in the bathroom.  I weighed myself right before I got dressed to ride to the start.  The race was hot, in the lower 90’s, with the humidity close to matching.  I took a bottle nearly time I went by the feed zone, but that was over 10 miles I think.

As usual, the race got faster at the end and I was feeling better and better.  There was a big split on the Manayunk Wall, which I made easily.  The finish laps were faster than any other time of the race, and I was riding faster, I felt better.  I don’t remember how I finished, but good.  I probably drank a beer and then rode back to the hotel.

When I got to the hotel, I striped down to shower and saw the scale.  I weighed myself and was 13 lbs. lighter than when I left.  That surprised me.  That was after drinking close to 15 bottles and a beer the previous 7 hours.  I was riding much better than last hour of a 6 hour race, having lost over 13 lbs, mainly through water loss.  That would have been close to a gallon and a half of water, by weight.

I started thinking about this for MTB racing.  I had heard that a few guys, had been taking diuretics before the races, which was completely illegal.  That they were shedding 8 lbs or so before the start.  We were talking about it and most the guys thought that it would be insane to be that dehydrated that much before a race.   I think that is wrong.  Here is a link to a abstract that says 3% weight loss through dehydration doesn’t affect performance.

I disagreed.  We’d done a study with the USOC, Olympic Training Center, getting weighed and hematocrit tested, before and after the races.  In a 2 1/2 race, most the guys lost somewhere around 6 pounds, which was on par with what I lost in Philadelphia, considering the time. Here’s a link to an abstract that says that being 3% light, through dehydration, doesn’t affect performance.

If I would have started the race 6 pounds lighter, because of dehydration, then I would have lost the 6 pounds and been close to the weight I finished Pro Nationals.  And I had ridden good at that weight, that dehydrated, on the road.

If I was climbing on a MTB that light, over 10 lbs., it is nearly a chainring difference, half the weight of my bike.  I’ve done this through dieting, but it only works for one race.  I have tried staying that light and always got sick after a couple weeks.

I typically don’t drink much training.  I think this season, early, I didn’t touch a water bottle the first couple months I rode.  Kansas isn’t that hot, but can be pretty hot sometimes.  I’ve ridden, many times, where I drink as much water as I can on a ride.  I fill up my bottles a couple times on a 5 hour ride.  Usually stopping and buying something ice cold about 1/2 way in.  Even so, I can come back 8-12 pounds lighter after a 5-6 hour ride.  (I’m really don’t sweat that much, like I don’t drip sweat all the time.) That is with consuming as much liquid I can find.  (I don’t use a Camelback.)

Anyway,  a Sky doctor saying that Froome being 2 kgs. lighter, through water loss, would aid in his ability to climb, wouldn’t surprise me at all.

I've done a fair amount of testing, most times, sweating a ton. My wattage historically has stayed constant.

I’ve done a fair amount of testing, most times, sweating a ton. My wattage historically has stayed constant.


19 thoughts on “Racing Dehydrated/Lighter

  1. Joe

    Seems like the kind of strategy that could get a rider in trouble unless he was closely monitored, maybe not the kind of thing your average amateur ought to mess with in hot weather.

  2. Dude Ron

    Super Fly your gunna fly Highhhh! That Old Philly race had classic miles like 155; Bloated up riders usually finished fast or at least finished. Froomies mtn stages rarely go over 120 miles. Good diagnostic analysis Tilly! Shout out for Danny Yooo

  3. janna

    I think it depends… I hardly ever drink water while riding, while racing yes though for I’m going hard.
    My body type is such that I retain a lot of water, almost like a camel really. I’ve dehydrated mildly after doing 150km rides in 30oC heat, but for the most part I don’t drink much water. I think a number of factors come into play on water intake – how hard someone is training/riding, body type, how fit someone is, and training the body to adapt. The body is an amazing element in that one can train it over a period of time and in that it can sustain a lot of abuse. I’ve known people that have ran for 111 days over the desert an amazing defeat…

  4. Bryan Barber

    I have a good friend who is a Brazilian jujitsu champ will occasionally drop 10 or 12 pounds of water for a fight. He’s been doing it for 10 years and claims no change in performance.
    Personally, after four years of participating in a Monday night shop race, I found an undeniable correlation between how hard I worked during the day and how well I performed in the evening. (ride duration less than 1 1/2hrs) It took at least two years to figure it out because I was determined to prove if I took it easy at work I would perform better. A harder workday meant a better race nearly every time. My conclusion was that, a hard days work(breaking concrete/framing a roof) was the ultimate warm up. However, in this age of watts over pounds, it would seem more likely that it was the weight loss that occurred during the day.

  5. Steve

    At Western States 100 mile run, the doctors weighed us during the run. Their conclusion was that 7% loss was getting into the danger zone. I lost 10% one year, and had trouble getting the blood pressure up (thick blood). Smaller losses are ok, I think.

  6. Bolas Azules

    Might work well for one day races but I’m not sure of the daily reduction and replenishment of fluids would serve your muscles well over multiple days. In stage races there are days when it’s hard to just get out of bed and other days you can walk down the stairs with no problems so there must be some variables at play other than a hard day in the saddle the previous day. I always thought it was a combination like quality of sleep, combinations of foods / nutrition, timing of fluid intake… things I always had a harder time keeping track of. Just my thoughts

  7. jpete

    What was that Frank Schleck got popped for again? That’s right, a diuretic. They are also reputed to be used as masking agents, no? Kinda makes his defense hold less water, in hindsight. oh, now that’s puntastic. sorry about that.

  8. KrakatoaEastofJava

    Froome and his Sky people seem to drop these “hey, did you know ____?” tidbits from time to time. I personally think it’s all part of the plan to manage everyone’s perception of his physiology. That way when people start questioning another completely INSANE performance stat, they can refer back to the intelligently-placed “plant” article.

    And remembering back, Lance did it, as well as Wiggins. Now I have an eye out for it. I hate it when people try to get their advance version of a story–before it becomes a story.

  9. JB

    Did you hear that Froome recently got a DNA test and he’s 35% Kenyan. Explains a bit of that endurance, doesn’t it?

  10. jpete

    unless it doesn’t. I saw an undercover documentary a couple years ago where they were going with Kenyan runners to see the doctor for drugs. I’ll post it later if I have the time to find it. I think the myth of the Kenyans has been debunked. Here’s some on a more recent scandal:

  11. MV

    A rider we know drank famously little during rides we drank 4 bottles or more. This year he was confronted with life threatening DVT’s in legs and lungs after an event.
    Something to think about for everybody.

  12. Dude Ron

    How many bottles did Floyd Go Thru on his epic stage in 2006, like 44 or something of course the Testo-Patch had to be rehydrated! Yep alot of it is human physiology like these days I guzzle lots a water on rides but back in the 80’s n 90’s I could ride over 100 miles on just a pint bottle, heck I surely didn’t wanna carry a bottle in my pocket just too much weight!! I been thru the desert on a bike with no name bahaha!

  13. Davey

    The release of “functional dehydration” is to prep us for Froome’s performance gains in 2017. When he dropped the fat and kept the power a few years ago he went from pack fill to multiple GT winner. Imagine what is possible when he drops the water with no loss in performance. He could win everything in 2017! No fat, no water, all muscle. Unfortunately not at all believable.

  14. KrakatoaEastofJava

    Having once believed that I generally didn’t need to worry much about hydration, my mind was very much changed one day in 1986. I did the 77-mile “Tecate-Ensenada” ride with that same friend I mentioned in a different post. We got separated almost immediately. So I decided to “totally go for it” and try my best to finish well. It was very hot that day, but par for the course in my home of sunny SoCal. No big deal.

    I had a great ride and I passed literally thousands of riders (as I started at the back). I remember once trying to get water at one of the rest stops, and finding the trucks were either completely out (odd, as I was at the front now) or just simply not there. So I plugged onward. I did start to get cramps during the big run-in on the coast, and it felt like just another hot and tough day on the bike. Business as usual. I’d done this hundreds of times already.

    They handed 18-year-old-me my free Tecate beer after I crossed the finish line. I guzzled it. And that’s when the vomiting started, From that point onward, any attempt at liquids or solids were soon met with dry-heave vomiting. It was the most agonizing experience I’ve ever had. I was with a large group for my transportation (American Youth Hostels) and that was mostly a group of leisurely riders who took their sweet time in finishing. I finished hours ahead of most of them. We had a hotel room to change and clean-up at, and I was just laying there outside bent over for hours and hours. Someone suggested I go to a hospital, and I had visions of dying in a fly-infested hovel in Mexico. “No fucking way” was my reply. “I’ll go to the E.R. as soon as we get back. That was 3AM. Well over 12 hours after I finished.

    Several IV bags had to get pumped into my veins. The doctor sat down and talked with me, asked me what kind of athlete I was and how I came to be there. “Take a drink every five minutes no matter how hot it is, ok?” is what he said. Apparently I’d almost died from Heat exhaustion. You never know when your body is going to change the game. Don’t fuck with dehydration as a way to get results. That’s my advice.

  15. paul boudreaux

    Seems like hydration during an endurance race is not something to get too cavalier about. Certainly don’t want to take in any more than you need, but you can go into an unrecoverable spin pretty quick if you get on the wrong side of the hydration equation. Seems like there are lots of mentions of cramping on this site too.


Comments are closed.