hDrop – Wearable Hydration Monitor

I *just* received my order of the hDrop gen 2 wearable hydration monitor, and used it for a short 45 min easy Zone 2 run. Based on my interest of sweat analysis, I was curious to compare my results to other tests I have done in the past. I plan to continue to use it for more sessions, and it will be interesting to see how the results fluctuate with the seasons.

MetricPrevious ValuePer hDropNotes
Avg Sweat Rate37Oz/h16.4Oz/hMy previous values were cycling, temps were relatively cool
Avg Sodium Concentration716mg/L – 1023mg/L901.1mg/LRange of 5 tests, last 3 were all at 1000mg/L +- 50.

After my first quick and dirty test, the unit is probably quite accurate on the sodium concentration, but I am unsure about the sweat rate. My past sweat tests were done based on weight loss during the exercise, cycling (not running) and majority were indoors. Based on the effort and ambient temp, I think around a 500ml sweat loss seems correct. read more

Endurance Racing – Sweat Loss

As one of the three important Fuel and Hydration, sweat loss, and more specifically, the replacement of fluids, is an incredibly important aspect of endurance racing, and is strongly correlated to race day survival, performance and recovery. The other two aspects, fuel (primarily carbohydrates) and electrolytes (primarily sodium) are the other two components. Without any one of the three, long distance and endurance events, or races, become considerably more challenging, and the chances of you finishing, drastically diminish.

Understanding how much fluid you have to consume during an event is determined by a variety of factors and variables. A few of the variables:

Time of Day, Heat, Humidity, Diet, and Effort. In addition, your sweat rate is unique and may also change throughout your life. Unlike your relative sodium concentration, which generally is constant throughout your life and in the majority of circumstances. read more

DIY: Endurance Fuel

Running Notes


Zone 1: Less than 85% of LTHR – 136

Zone 2: 85–89% of LTHR – 136 – 143

Zone 3: 90–94% of LTHR – 144 – 150

Zone 4: 95–99% of LTHR – 151 – 158

Zone 5a: 100–102% of LTHR – 159 – 163

Zone 5b: 103–106% of LTHR – 163 – 170

Zone 5c: More than 106% of LTHR – 170+

Swim Technique Notes

  • Rotate body to gain more reach
  • use hand and arm to catch the water
  • Keep shoulders down/low and use lats , not shoulder to pull
  • Start slow and get faster with pull
  • pull all the way down past waist
  • Breathing:
    • keep one google eye in water, one out
    Think about making your body as long as possible with timing


    • Rotation
      • kick, check rotation, arms at side
      • rotate kits and shoulders, everything in sync
      • 6 kicks one side, 6 kicks flat, 6 on left side
      One arm forward with fins on
      • Swim on side, like superman, make sure body is parallel to wall
      • try to breath
      Skull Drill
      • Use just your hands and work in a small figure 8 rotation to propel yourself down the pool (probably very slowly)