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Sweat trial question

Satish PunnaSatish Punna
in General Training Discussions

I'm planning on doing a sweat trial as part of an early morning trainer ride.  Is it ok to consume my usual early morning fluids (coffee, water)  prior to the weigh in and workout , or do I have to do the 1st hour of the workout dehydrated (from fasting overnight).  

Thanks!

 

Comments

  • Shaughn SimmonsShaughn Simmons

    The method I use to perform mine is that I consume as much as I need before I begin the test.  Not recommended that you go into the test dehydrated.

    Key is to weigh yourself right before you get on the bike.  I try to simulate temps and humidity of race conditions as much as possible.  I drink as much as I need to during the test.  Once I am finished, I weigh myself immediately and take the difference of my beginning weight less my ending weight.  

    For simplicity purposes, let's say I lost 2 lbs during the 1 hour test.  1 gallon of liquid weighs ~ 8 lbs and is 128 ounces.

    I lost 32 ounces plus the 12 ounces I drank or 44 ounces in this example.  Let's assume I performed the test at 80 degrees and 60% humidity.

    Now I know I need to drink about 2, 24 ounce bottles/hour (48 oz) under similar conditions and add to that if I am racing at 85 degrees and 70% humidity.

    The amount of sodium in sweat averages about 500 mg sodium/lb sweat (and ranges from 220 to 1,100 mg) If you lose two pounds of sweat per hour for four hours of intense swimming, biking, running, etc., your sodium losses become significant (4,000 mg)

    For a long course IM under extreme conditions given a high sweat rate as validated by the sweat test, Gatorade Endurance alone is not going to be enough sodium and you may be required to supplement with salt tabs.

    When supplementing with heavy quantities of salt tabs be sure to use "Buffered salt tabs" like Salt Stick Brand.  Tabs that are not buffered when taken in large amounts can cause bad stomach issues.

    SS

  • Mariah BridgesMariah Bridges
    Nothing need be said once SS has answered! He da man!
  • Satish PunnaSatish Punna

    Thanks!

  • Satish PunnaSatish Punna

    So I did the sweat trial first thing this morning:  Was probably around .7 

    https://www.strava.com/activities/611815565

    I ate half a banana, and drank about 22 oz (650mL)  of water.  Weight before was 141.1 lbs (64kg).  Weight after 1 hr was 140.7 lbs- net loss lets say 1/2 a pound.   Prior to initial weigh in I had consumed 2 glasses of water and a cup of coffee.  

    Interestingly, as the trial progressed my HR and RPE came down as watts went up, probably reflecting improving hydration status as what was in my stomach was slowly absorbed.  This took about 30 minutes and validates for me taking it easy and pushing fluids at the start of the bike leg.  

    So .5x16= 8+22 = 30oz (890mL) for cool days, and .5x24= 12+22= 42oz (1242mL) for hot days (at least).  

  • Shaughn SimmonsShaughn Simmons

    Looks really good and as expected Satish.  Will you be at a race venue expected to be in the same range of your test temps?

    If no and your venue is expected to be at 80 degrees F or higher, .....you may want to see what that means in terms of sweat loss a little later down the road in your plan via another test.

    Keep leading......

    SS

  • Satish PunnaSatish Punna

    Thanks!

    Tremblant IM is the gorilla in the room for me- will definitely be warmer than in my pain cave this morning but I'll have lots of opportunity to test between now and then.  Now to figure out how to transport all that fluid without carrying too many bottles and still avoiding the early aid stations.  May have to take 3 bottles with me out of T1 and drink/discard one at the earliest opportunity.  

  • [Deleted User][Deleted User]

    Hey Satish this may be a little outside EN protocol where aero trumps all but at Texas this year I carried my usual 6 bottles from the start - 3 on bike and 3 in pockets in jersey.  I use EFS which has all the electrolytes you need without adding sodium.  I believe if you use Infinit you can custom it that way too. I have lost too many nutrition bottles in races that I carry everything now. (2 on frame and 1 between arms).  I may lose a bit on aero but what I gain is knowing my nutrition is dialed in and I don't have to stop at special needs = priceless. All I take from bike aid stations is water to drink, pour on me and then discard before the penalty zone image For Maryland I may go back to 2 rear bottle cages (Gorilla only) and 1 between arms and keep the frame clean. 

  • Satish PunnaSatish Punna

    Thanks Dan

    I think I need 2 bottles of fluid/hr. So my plan at the moment is to carry 3 bottles of my home made nutrition at the start of the bike, and pick up water at the aid stations.  After 3 hours I am going to pick up gatorade and drink 2 bottles of that per hour plus water, gels, and saltstick tabs as needed.  This seemed to work well on my last and final long ride. 

    My bike is setup to carry to 2 BTA bottles (unorthodox but seems to work) and 1 behind the seat. 

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