Today I rode my new bike for 3:30. I rode an easy pace because I was training with a buddy who is tapering for IM Wisconson. We rode a very hilly 53.4 miles and averaged 15.3 mph. That’s actually not a bad pace for such a hilly route! My average heart rate for the ride was 122 bpm, which is middle of Zone 1 for me.
Loving the New Bike
BTW, I love the bar end shifters on my new Valdora Bike. It didn’t take me long to get the hang of what gears to use when. Climbing hills is a bit harder with this bike, tho. The easiest gear on the Tri bike is harder than the easy gear on the middle chain ring of my road bike. And that’s not even counting the small chain ring, aka, granny gear. I was able to handle the hills just fine, tho. This course is worse than the Duke 1/2 course, so I think I’m good to go. Also, I did a 2.5 mile run immediately after the bike ride to see how running off this bike feels. I felt a little stiff the first 15 minutes, but then got into a good groove. I think a few more rides on this bike will work out the stiffness. There’s always an adaptation period on a new bike (or an altered bike, as I have learned well in the past couple months!) Because of this adaptation, I was going to resist the temptation to use the new bike for any races this season. But, since my road bike is out of commission for 10 days, forcing me to train on this bike, I now think using this bike for the rest of the season, is the best choice. And anyways, it’s a TRI BIKE!!!
The Sweat Rate Test
I did a sweat rate test. The purpose of a sweat rate test is to figure out how much water per hour that you sweat out. Then, during a race, you consume that much water per hour. If you consume more than you need, then you’ll have to pee. I don’t want to waste time peeing during the Duke 1/2 this year.
First we swam in the lake for 50 minutes. Then I dried off and put my bathroom scale in the middle of the road to weigh myself. Who else but a triathlete would do that? I wish I had thought to ask my friend to take a picture of me.
Then we headed out for our bike ride. It was a fun ride through the countryside of Chatham and Alamance Counties (NC). We crossed the Haw River twice. Three adorable brown puppies chased us. I yelled “No” at them so they wouldn’t be running in the street. Two puppies stopped, but a third kept running after us. They were so tiny – their owner’s really should not have let them run loose like that.
When we were done riding, I stripped down to my bathing suit and dried off. Then put the scale back in the middle of the road for another weigh-in. LOL!
The Data
So, here are the results, for my own records. I’m sure nobody else cares about this data!
Weight Change:
145.2 Weight before workout
– 143.2 Weight after workout
= 2 pounds or 32 ounces Lost
Liquid consumed:
8 ounces of boost (meant to drink that before weigh in, but oh well)
+ 80 ounces H2O (3 water bottles full x 24 oz each + an extra 8 oz)
= 88 ounces total water consumed.
Since I lost 32 ounces of weight, add that
88 + 32 = 120 ounces lost due to sweat in 3.5 hours.
120 ounces / 3.5 hours = 34 ounces per hour sweat rate.
Temperature: 85 deg F, 63% humidity.
Hmmmm….it just occurred to me that this may not a very good test because I was not going at race pace. I will do this again on a 1 hour ride at race pace.
Did another sweat rate test today, Tues Sept 2
Starting weight is 144.6
Ending weight is 142.6
————————
Lost 2 lbs ~ 32 ounces
Drank 20+20+17-8(left in bottle)=49
49+32=81 ounces in 2 hours = 40.5 ounces per hour sweat rate
Workout: 2 hour bike ride in Zone 2, with 34 minutes in Zone 4 (threshold)
Heart Rate: 143 avg hr / 167 max hr
Weather: 86 deg F, 35% Humid
Did another Sweat Rate Test (for a brick workout) on Sept 4
145.6 Start Weight
143.5 End Weight
—————–
2.1 lbs = 33.6 ounces.
Drank 20+20+20-6(left in aero bottle) = 54 ounces consumed
54+33.6 = 87.6 sweated / 2.25 hours = 39 ounces per hour. Wow, prety consistent.
HR: 143 bpm avg (was a Zone 3 race pace workout, but traffic on the bike ride slowed me down)
Weather: 86 deg / 46% humidity
Yet another Sweat Rate Test on 9/7/2008:
146.8 Start Weight
144.8 End weight, after peeing I weighed 143.4 (it was hard waiting till I weighed myself)!
—————–
2 lbs lost = 32 ounces
Consumed 20+20+20+20-6(left over) = 74 + 32 lost = 106 total sweated out.
Time = 3.5 hours
106/3.5=30 ounces per hour.
Avg Hr = 137
Temp = 83 deg / 53% humidity
One last Sweat Rate Test Sept 8 (running only this time, and in the heat of the day)
146.2 starting weight
144 ending weight
——————–
2.2 lbs lost = 35.2 ounces
Consumed 64 ounces
64 + 35.2 = 99.2 ounces in 2 hours (took me a while to get home!)
That equals about 50 ounces per hour. Wow, that’s the highest so far.
AVG HR was 140
Weather: 89 deg F, 45% humidity
Just found your sweat rate test and I’m a firm believer in knowing my sweat rate. I actually have two sweat rates, one for the bike and one for the run. They are definitely different so I plan accordingly. I live in Houston and the weather in the summer is usually in the 90’s with 90% humidity. My sweat rate on the bike is about 42 oz per hour and on the run it’s about 62 oz per hour. Even at the same heart rate… which I still don’t understand. I went even further to figure out the sodium losses so that I replace enough.
Terry – awesome info, thansk for sharing your comments! How do you test salt rate?
(sorry for the lenghth!) 40 years ago while whinning about how painful the balls of my feet were following a hot century, I was informed it was dehydration. In the early days to ‘save time’ by reducing pee stops not enough water was used. I am forever in debt to the informant and became a real ‘water nut’ telling one and all that it’s vitually impossible to maintain a proper fluid level while riding aggressively. I splurged on a beam scale that measures to 1/10th pound and learned that a 10-12 pound loss during a century is not ‘weight’ loss and I lose about 3 pounds while sleeping (perspiration, respiration & urination-upon rising).
Leading club rides with weigh-ins and weigh-outs helped members realize the importance of drinking enough for comfort and performance. I’ve only recorded one serious ride of not losing water weight. Getting up early to prepair for our 150 mile ride I felt a hint of a sore throat which left me with a choice of going back to bed or super-hydrating! By becoming aquainted with nearly every tree along the route I arrived home the same weight as at the start. All it took was thirty pints of fluids plus whatever water was in the food! There was no sore throat.
Harold is right that the weight numbers won’t match exactly in this type of comparison. However, the margin of error is low, especially once you consider how many other factors are present (heat, humidity, fitness level, etc.) It’s practically impossible to account for everything in every situation, so I prefer to use the 1:1 comparison to keep things simple.
Have fun getting used to your new bike! It must be great having a tri bike now!
Must be a rounding thing. The few sweat test calculators I’ve seen use a 1 fluid ounce (volume) of water weighs 1 ounce calculation. I always just assumed that’s what it actually weighed!
Just discovered your blog today. I think you may be confusing weight ounces (16 oz/pound) and liquid ounces (8 oz/cup)? A weight ounce is around 28 grams; a cup of water is a little less than 1/4 liter, or 250 grams, thus 30+ grams. If the difference is 2 grams, your calculation for 120 oz would be off by about a cup, I think. I looked up the conversion factor for water. It is:1 fl. oz. of water weighs 1.0425 oz.