Adarq.org

• i lost about 1.2L of sweat during the run, which is in line with what i already knew from previous weight tests. the recommendation to drink 26-30 oz of water per hour (770-890 mL) is also in line with what i'd already learned. turns out i'm in the 45th percentile for sweat rate, or what they call the "moderate" range. i'm not surprised to be in the fat part of the bell curve, but i am a little surprised to be below average. the more you know.
• i lost 1568mg or about 3/4 tsp of salt (NaCl) during the run, which is in the 61st percentile, or "significant" range, per levelen. the report recommends including some carbs along with salt in exercise drink because your body doesn't absorb the salt as efficiently without the presence of carbs. that is interesting, hadn't read that before.
• of course, levelen is a supplement company, so the report comes with recommendations for how to use their products to best replace what i'm losing. fortunately, it's not hard to extrapolate to a recipe i can make at home.
  

High total energy expenditure (TEE) and rate of water turnover (rH2O) using doubly labeled water (2H218O) have been reported during single-stage and multistage ultraendurance events. At the 161-km distance, less is known about the interaction of TEE, rH2O, and ad libitum energy/fluid intake. This is especially true during the postrace recovery window.

Purpose: To measure TEE, rH2O, and ad libitum energy/fluid intake during a 161-km ultramarathon while extending the TEE and rH2O measurement window to a 7-day postrace period.

Methods: Doubly labeled water was used to monitor TEE and rH2O in 2 male ultrarunners (R1, R2) during a 161-km ultramarathon. Self-reported energy/fluid intake was recorded at crew-accessible aid stations.

Results: Both runners completed the race in 32.8 hours, and TEE over this period was 65.8 MJ (6.5 × basal metabolic rate [BMR], 15,723 kcal, 11,225 kcal·24 h-1) in R1 and 66.5 MJ (7.4 ×BMR, 15,888 kcal, 11,293 kcal·24 h-1) in R2. Race energy intake for both runners approximated 50% of TEE, with reported fluid consumption of 21.8 L and 15.7 L for R1 and R2, respectively. rH2O during the race was 14.6 L in R1 and 15.5 L in R2. During the 7-day postrace period, total TEE and rH2O were 94.7 MJ (1.9 ×BMR, 22,634 kcal, 3245 kcal·d-1) and 41.8 L for R1 and 80.0 MJ (1.8 ×BMR, 19,116 kcal, 2721 kcal·d-1) and 24.0 L for R2, respectively.

Conclusion: These data illustrate the expected nutrient and fluid budgets for ultramarathons and describe the challenge of restoring acute negative energy balance following these events.