Sweat Rate Testing
Importance of Sweat rate testing (0:00 - 6:22 mins)
We hate to use the phrase "Game Changer" yet so often we hear this from athletes with feedback where they actually start to understand what their hydration requirements are Historically they've either been over hydrating or under hydrating, then as a result of getting that under control through repeated sweat testing, they have a vastly better outcome in terms of training and racing. As Alan highlighted I think that the final piece of the puzzle of hydration is recovery. When you do weigh yourself after your session, you know what that percentage of body weight lost was. In doing so, you understand the fluids requirements (125-150% of weight lost) to consume to optimally rehydrate within 1-2 hours post-exercise. We often talk about an anabolic window in terms of protein synthesis and consuming enough protein. Consuming enough carbohydrates to replenish glycogen stores. Maybe we should be thinking about that hydration window in the same way to ensure optimal hydration status. This "hydration window" is that 1-2 hours post session.
How do you do a sweat rate test? (6:22 - 13:58)
Firstly, follow the prompts in Fuelin. We will tell you when to do sweat rate testing. When it says log sweat rate that's the first indicator. It's telling you to log a sweat rate test. Weigh yourself before the session. Jump on a set of scales - I would recommend not having a set of scales that are connected to Garmin or anything like that. Just have an old school, shitty set of analog scales with a little needle or if you want you can get digital. But don't have them connected to anything because you're going to be using this all the time and do not need to recording your weight in Fuelin like that. You probably want a couple of them - one set for the car for when you're driving to do your ride. You want a set at home that you can jump on weigh yourself. The test should be done naked. If you don't want to do it naked or cannot due to the environment, then do it at least in your bra and undies or just in your undies. Do that then weigh yourself after the session. There are your two points and that's as simple as it gets - weigh yourself before session, weigh yourself after your session. Enter the details into Fuelin and we will do the rest
Data interpretation (13:59 - 21:43)
The Fuelin app will outline several key objective and subjective elements of your sweat rate tests. Firstly, it will provide ongoing aggregate information from all the tests you input into Fuelin. This means the more tests you do, the more accurate the data becomes. Single tests are fairly useless. It is important to build a picture or "sweat bank" in order to gain a thorough understanding of your requirements on the bike and the run at differing temperatures and at different intensities.
The key data points will be;
- Average and Peak Sweat Rate litre/oz per hour
- Average and Peak Fluid Intake Rate per hour
- Recommended Fluid Intake per hour
- Average and Peak Sodium Intake per hour
- Average and Peak Sodium Intake per litre/oz
- Average and Peak % Bodyweight Loss
- Gi Discomfort Ratings
What to do with your data? (21:44 - 35:11)
As an athlete, you should be following the recommended fluid intake amount per hour that Fuelin provides. This amount will be adjusted continuously based on your data. The amount recommended will differ for bike and run. It will also be specific to the intensity and the temperature of each of your tests. Athletes should be purposeful about testing in conditions that will mimic their race conditions.
QUOTE TO PONDER
"We often talk about an anabolic window in terms of protein synthesis and consuming enough protein. Consuming enough carbohydrates to replenish glycogen stores. Maybe we should be thinking about that hydration window in the same way to ensure optimal hydration status.”
SCOTT TINDAL
NUTRITION ELEMENT TO CONSIDER
“Every time (the athlete) is doing a session over 60 minutes they are sweat testing. It just becomes habit. They're jumping on the scale. They weigh themselves before the session. They weigh themselves after. They get an understanding of what they're losing and what they're consuming in that session but it also helps them plan that recovery”
SCOTT TINDAL
Scott went into detail about the athletes who have their hydration strategy under control are the ones who gather the most amount of information. There is no trick to this or these athletes success. It is not uncommon for athletes to have multiples of tests . From 40, 60 and even 100's of data points accumulated over months of training. The habit of jumping on the scales for sessions that last more than 60 minutes becomes ingrained in their training. Much like strapping on your shoes and getting your carb products set up for your session, having your scale ready is all part of being as professional about your craft as possible. It is never too late to get started.
Next week's Q&A is HYDRATION MASTERCLASS:PART 2 with Dr Alan McCubbin.
