Not long ago, the popular thing in water bottle hydration was aluminum. I must confess, I was pretty hooked myself — icy cold water, cool styles — it was all quite awesome. But then the controversy around aluminum kicked up. And I found myself doubting the wisdom of continuing to use my aluminum water bottles, like Sigg. Now that I’ve found the Thermos double-walled vacuum insulation water bottle, it may be time to toss my Sigg bottles altogether.
The double-walled insulation water bottle by Thermos, branded for UnderArmour, is a great stainless steel water bottle across the board. First of all, it has that icy taste that I love from a metal water bottle. No plastic flavor transferring into your water, as you might get from plastic bottles. And this bottle is food-grade stainless steel — a huge advantage, given the worries that aluminum can leech into your drink. For years, some have accused aluminum with causing Alzheimers, but I have yet to see conclusive evidence of that threat. However, I believe for an aluminum bottle to be food-grade it must have a liner. Just to be safe, I’ll stick with the stainless steel.
What’s more, Thermos claims that it can keep a drink cold for 12 hours. I put it to the test – a few 12-hour sessions with the bottle (overnight on the counter, in the car on a hot day, etc). My unscientific methods seemed to support the claim. Thermos attributes this cold retention to their razor-thin vacuum double-wall construction. Most of us know that a double-walled construction keeps the drink cooler because of less direct heat transfer from the outside material to the liquid inside. There are lots of double-walled products on the market. But Thermos claims that their double-walled construction, which is able to leave a space of mere millimeters between the two walls, allows less bulk for your bottle. Translation: carry more liquid, not more vacuum space, with the same size bottle.
Thermos went so far as to commission a study using their bottles to serve cold water to athletes during exercise contrasted with athletes who were served lukewarm water to hydrate during their workout. The study found that drinking the colder fluids kept core temperature down among the athletes served cold water, which translated into measurably higher performance in both the broad jump and the bench press by those athletes.
“It’s not only how much or what you drink while working out, but also the temperature of the fluids that drives
performance. Cold water (40°F), as provided by vacuum insulated hydration bottles with Thermos®
technology, has been shown to keep core temperature down and increase power output. Preliminary research
indicates that keeping core temperature down prevents heat-related stress on the body which leads to fatigue,
protein denaturation and other performance reducing effects. Further, cold hydration has the potential to
increase strength and power output, improving training results.”
The effect of cold hydration during an exercise session combining both strength
and energy systems development training on core temperature and markers of performance – conducted in 2011 by Phillips AC, Lafata DL, Sims ST at Athletes’ Performance in Phoenix, AZ.
So, the science seems to be a sound argument for replacing your plastic water bottle with this stainless steel double-walled vacuum bottle by Thermos. And the icy taste is definitely a treat. What’s more, the UnderArmour branding provides a number of different designs (mine was a gun metal gray), many with bright colors and the ubiquitous UnderArmour logo. But here are a few more items worth noting:
- Rubber grip around the middle makes it safe to pick up, even after this steel bottle has been sitting in a hot car all afternoon.
- Lid is a tip-to-drink lid, not a squirt or suck nozzle, which is ideal for a non-squeezable metal bottle such as this.
- The bottle is a little too tall and narrow for most of the cupholders I used with it. I found it tipping around in the car all the time (I drive a Toyota 4Runner and a Nissan Armada), and falling out of the kids’ strollers’ cupholders. A bit of a pain, so just make note that it probably works better stuffed into your workout bag than sitting in the car’s cupholder.
- Instructions included with the bottle note that the bottle is better at keeping cool drinks cool than keeping warm drinks warm. It’s 91F in Utah right now, so I haven’t really been drinking too much cocoa. I’ll take their word that this bottle is designed for cool drinks, not warm.
- Instructions also state that for best results, put some cool water into the bottle for a few minutes to cool down the inside before filling it with your drink of choice. They say that it will hold the cool longer if you do this. I tried it, and it certainly didn’t hurt.
All in all, I think this has finally moved me off of aluminum water bottles. I’m very pleased, and I hope they make some smaller-sized ones that work better in cupholders — because I would pick up one of those, too.