By Col. Michael Panarisi, AEDC/PA
/ Published January 11, 2011
ARNOLD AIR FORCE BASE, Tenn. --
Spring has sprung, temps are rising (FINALLY!) and you've committed to cranking out some miles on your bike or putting some serious hurt on the pavement with your new shoes.
But somehow, it's just not working out...you just can't seem to get to that "next level." What's holding you down? The solution might be closer than you think. The higher temps magnify the problem, and the problem could be dehydration.
"What? I'm not thirsty." Oh contraire! You just don't know it. A little basic biology shows us why.
First, let's look at what we're up against. Our workouts challenge more than just our muscles. The cooling system has to ramp up, and our oxygen/waste product transport systems get put to the test as well. These systems share a common source...our blood supply. The problem is our workouts deplete our "life fluids" at the very time we need them most.
For the sophisticates in the crowd, it's a matter of "volumetric efficiency." For max efficiency, the pump needs two things...good mechanics and the right amount of fluid. Our workouts improve the mechanics, but they drain the fluid.
In our exploration of the heart beat myth, we saw that our heart is at the center of a complex pumping system. While aerobic activity makes the pump stronger over time, it's only as good as the juice it has to pump. When we "drain the reservoir," we make it work harder, robbing performance and causing early fatigue. Waste products build up and reach higher concentrations in an ever reducing volume. It gets worse.
Since we see the heart as the engine in the aerobic cycle, it's easy to overlook its vital role in cooling and waste removal. And in these tasks, keeping the tanks full is critical. Yet we literally run them dry with every breath we take.
There's a huge blood volume in the lungs, primarily to exchange oxygen and carbon dioxide. But the physics of the problem explains the secondary role in cooling. Unless the air you breathe in is hotter than your body temp, every breath literally cools the blood, making your lungs a natural "radiator." This is almost a freebee, except for one thing. Unless it's raining (i.e., the relative humidity is close to 100 percent), every breath transfers some water into the exhaled volume.
At lower temperatures, this transfer represents a volume loss that exceeds the loss we experience in perspiration. At the higher temps, it's a double whammy...we perspire more, and the cooling effect drops. The only way to combat this as we increase the demand on the system is to keep the fluid volume as high as possible, and that's the problem with dehydration...it hits every aspect of our performance. Re-hydration is not a "post workout" issue. We need to add fluids during the workout to get to the next level.
I can hear it already. "But I'll get a belly cramp" or "I don't like that sloshing feeling." OK, I'm with you. But I'm not talking gallons here. There's two parts to this solution, and the "before" is just as important as the "during." (Though "after" is a big player in recovery, so we'll hit that at the end). That's the problem with our thirst reflex. It just kicks in too late. Some doctors will tell you the trigger starts around the 3 percent dehydration level. That sounds trivial; but since you're nearly unconscious at the 10 percent level, by the time you're thirsty, you are a long way from peak performance. The trick is to stay ahead of the curve, the hard part is knowing when your tanks are full.
Since most of us don't work at the gym, we don't need to know, we can let physics take care of this for us.
Trick #1: Tank up on the way to the gym. I mean really tank up, on the order of a pint, maybe more. Just chug it. By the time you get into your workout, the kidneys will have sorted out how much of that you really needed, and at the same time, give you hard evidence of where your real hydration level is.
OK, so you drained a bottle, traveled and changed, and you are ready to get warmed up. What's next? If you were nearly fully hydrated, you won't need any prodding to head to the restroom along the way. If you are about to start your workout, and you just don't have "the urge," you are not fully hydrated. I can prove it.
When the urge finally comes, I promise it won't be "clear" and the darker the fluid, the more dehydrated you are. So the target is a little urge as you put on your shoes, and a clear stream tells you the tanks are as full as they can get. Now it doesn't count if you have "the urge" and you didn't tank up first. I'm talking about inducing an unscheduled trip, not just executing one that was lying in wait.
So the "before" is done, what's the "during" part. Very simple. I use "10 minutes, two swigs." This is really easy on the treadmill, elliptical, spin bike, or while weight training. In a typical workout, you'll drain a pint bottle in around 45 minutes. On the road or mountain bike, you can get the hang of it, just adjust the timing a bit until you are in a safe place. Not a good plan on a big downhill or in traffic. Running makes this a real challenge; and I admit, I rarely re-hydrate on a fitness run. Just haven't found a good way to beat the logistics.
But think about all the races you've seen ... events 10K or longer have water stops ... gee, I wonder why? It's not about preventing dangerous levels of dehydration, it's for the pros who are looking for that last 5 percent of performance. If your run is under 45 minutes, it's pretty tough to get dangerously dehydrated if you started out full. But if you really want to peak, you'll see benefit with a few ounces around the 30 minute mark.
So what about the "after" part? Even easier! If you did a vigorous workout, and you left some sweat on the floor, chug at least a pint before you hit the shower, then another on the way out from the gym. Don't worry about over doing it. You'll "give it back" shortly after you get back to work. If it's clear, you're done. If not (and I bet it won't be!) chug one more every hour until it is. You won't believe how much better you'll feel the next day if you typically stay dehydrated after a workout. I bet most do.
Re-hydration is easy to add to your portfolio, and has a huge "bang for the buck." And as we said before, water is your friend. You don't need those expensive, calorie/sugar laden sports drinks for a typical workout. Remember, the guys that invented "Gatorade" did it for the Florida football team...three hour practices in the summer heat. Your three-miler on a mild afternoon just isn't in that league. Stick with the tap and put the bucks you save towards that shiny new heart rate gadget!