Acumen Dehydration Watch


A name like “Deydration Watch with Fluid Check” could certainly make you squeamish because, after all, who wants to even talk about body fluids, let alone have them checked? But, being the serious investigative journalists that we are at SNEWS, we willingly subjected ourselves to testing Acumen’s new EON 302 Dehydration Watch with Fluid Check.

Basically, this is a sports watch that features technology to remind you to stay hydrated during workouts. And the best news is that there is nothing invasive about it – you simply program your weight and approximate exertion level (from a chart provided), as well as the ambient temperature and humidity levels, using a keychain-like gauge that accompanies the watch.

Then you start the stopwatch and get moving, and the watch periodically emits a faint alarm and displays your approximate fluid loss in ounces (or milliliters, if you choose), as well as the overall percentage of body fluids lost to sweat, when you hit loss numbers like .5%, 1%, 2% of body weight. The beeping serves to remind you to take a swig from your water bottle or reservoir hose, and it is allegedly based on an algorithm that is supposed to be fairly accurate for most people.

For extra reassurance, you can actually program the watch for drink intervals every few minutes or so, and the alarm automatically will sound and display the corresponding hydration information at those designated times. This feature could be good for long runs or rides – especially if you tend to forget to drink — but sort of seems to defeat the purpose of the monitor actually “monitoring,” or doing its calculations and telling you when to drink based on estimated dehydration levels.

Runners or competitors might appreciate the lap counter, the interval timer that you can preset and the weekly and annual event reminder. The unit also comes with a daily alarm, date and day of the week display and is water resistant to 30 meters.

This model can be upgraded for an extra $99 to include heart rate monitoring as well, which we would wholeheartedly recommend, as we found our wrists a bit heavy laden when donning our own HRM plus the body fluid monitor. Plus, a HRM would automatically measure intensity level, so we wouldn’t have to arbitrarily guesstimate this and program it in before our workout even begins.

While overall, we appreciated and understood the intent of the Acumen EON 302 monitor, after testing the unit we’re still scratching our heads a bit and wondering if it remains a bit of an answer to a question that hasn’t been asked – considering how Acumen is known for solid and well-thought-out products, this one surprised us a bit, as if an engineer got a creative tick without consulting with the marketing gurus. Granted, one of our testers did comment that she would have appreciated the unit on an 18-mile run recently when she actually did forget to regularly hydrate. But, for the most part, hydration is something most athletes (the kind of person who’s actually techy enough to want this watch) tend to understand and be quite conscious of.

During our month of testing, we found this unit a quite challenging to program and navigate through the menus to retrieve data. We found ourselves repeatedly pressing buttons and rifling through the not-entirely-clear manual to figure things out. This can be a pain, particularly when you’re out on the trail, road or in the gym and don’t want to stop the workout to fiddle around.

Also, to get an accurate reading, you manually have to punch in the temperature and humidity levels every time you want to use this. And if you’re programming it inside in the comfort of air conditioning, your numbers may be way off if you’re headed for a ride, run, walk or hike on a hot, muggy day. Or, if do a longer outing and the temperature and humidity change dramatically, as is likely, that negates the setting’s accuracy.

Other drawbacks: The alarm on the watch is fairly quiet, which may not be an issue if you are running on a quiet path by yourself at dawn, but becomes problematic if you are wearing headphones or, if you, like one of our testers, wear this to a group exercise class. There was no way to hear the beeps over the instructor and the music. And the unit is designed for one user only, so if your significant other wants to borrow it, he/she must program in his or her weight (which then overrides yours) to get accurate body fluid measurements.

It does come with a nice overview booklet (separate from the manual) that shares the importance of hydration, which some people probably still don’t understand or realize how it impacts performance. Oh, and it’s quite an attractive watch really – nicer-looking than most wrist-top monitors. We just wished it had been a bit easier to use; we think that with a few tweaks, it could become a valuable training tool for some people.

Our suggestions to make this a better product include:
1. Have the monitor automatically measure temperature and humidity. This must be possible in today’s world.
2. Allow room for more than one user to program in his/her weight and age. Maybe a feature for more advanced models.
3. Make HR monitoring standard on all models (so exercisers get more valuable. feedback and don’t have to program in their estimated intensity level). We don’t understand NOT combining them.
4. Add adjustability to the volume level so you can increase the volume if needed, or decrease it for quieter moments.

SNEWS Rating: 2.5 hands clapping (1 to 5 hands clapping possible, with 5 clapping hands representing functional and design perfection)

Suggested retail: $99 for base unit, $99 additional for heart rate monitoring

For more information: