Posted by Steve Magness
When we rely on scientific data, we tend to look at the conclusions as fact. After all, most people simply peruse the abstracts and jump straight to the last one or two sentences that basically say what the heck the article was all about. Even if we browse the article, we often skip the methods and the results section which tells what they actually found and head straight towards the conclusion statement where the author’s give us a “what does this mean practically.”
Problems arise when we interpret the conclusion as exact fact. Instead, it is the data that should be factual and relevant if the experiment was done correctly, and the conclusion is left for human interpretation and error. I’m not saying that the author’s concluding remarks are false or useless, as they often provide great insight. My point is that even the best and brightest of us make mistakes in interpretation and that’s when we run into problems.
It’s not the science or the data that is the problem. It’s often us.
Human interpretation is faulty:
Hydration provides a perfect example of when we take good data and misinterpret what it is telling us. Way back in the early days of marathoning and exercise science, some early pioneers took some data and found that there was a direct correlation between weight lost during the marathon and the finishing speed of that runner. Put simply, the faster runners lost more weight during the race. The data was right on.
The human interpretation wasn’t. Seeing this data, the conclusion at the time was that it was bad to drink water during a marathon. It seems logical enough right? The faster runners lost more weight and thus didn’t replenish their fluids as much, so taking water to maintain fluid loss most negatively affect performance. So for several years, the prevailing logic was that in order to maximize performance, runners should not drink. After all, there was a direct correlation between weight and water lost and performance!
When health became more important than performance and some more data come out that dehydration was a bad thing. We overreacted and decided to push full weight maintenance during the marathon, which resulted in a lot of problems, such as a huge spike in deaths related to drinking way too much water (Hyponatremia). This isn’t a post about that cycle but you need to know that to set the stage to where we are today.
Hydration today: Fastest runners still lose the most weight/water
Which brings us to today. Alex Hutchinson does a nice job summarizing the latest research, which not surprisingly found the same results that were noticed over a half century ago. (http://sweatscience.com/hydration-faster-marathoners-lose-more-weight/). Today though, we interpret the results differently. It’s essentially the same data, but the conclusions are remarkably different: We should simply drink to thirst. It’s okay to be slightly dehydrated at the end of a marathon. The key is listening to your body and figuring out where that sweet spot of consuming enough fluids versus forcing fluids down is.
One interesting thing about all of this is that it demonstrates how we easily can override our own body’s feedback signaling just because of the way we think and what we’ve been taught. Essentially, if we are inundated with the importance of (over) hydration enough, then we’ll ignore the thirst or fullness signals our body might send.
What do we take away from this example and the interpretation problem?
Well the simple answer is to drink to thirst. The complex answer though is that it might have been so long since we’ve paid attention to our thirst mechanism that it’s going to take some practice and adjustment. Which leads me to one a quick tangent: Paying attention to feel or running by feel is great, but it’s a skill most of us have to relearn. One of my former HS guys (who is just ran 14:26 for 5k for Texas! Congrats Will!) told me last week that it took him almost 2 years to figure out how to do a threshold/tempo run correctly. Even with emphasizing the importance of running by feel, and banging the concept into his head a million times, it took him 2 years to be self disciplined enough to stop letting his competitive instincts of running with some of the other guys like Ryan, take over and block the feedback he was receiving while running. Part of it was my fault because I was spending too much time making sure the (at the time) better and older guys like Ryan, Jeremy, and Cody were getting it and there was only one of me to run with everyone, and an at the time over 5min miler as a freshman didn't get as much attention as he should have!
On the science side of things, the lesson is a little more subtle. Instead of browsing the author’s conclusions on research, look at what the research actually found. Look at the actual results first, think critically, and form your own quick opinion before reading the Author’s remarks and interpretation. This way you’ll at least avoid falling into the trap of simply relying on others interpretation. If both you and the author’s interpretation matches up, you’re probably on the right track. If it doesn’t, then I wouldn’t jump right into whatever the research claims. Additionally, after reading the research, think if you could interpret the data in another logical way, just as the hydration data could be seen from two different viewpoints that were both seemingly logical at the time.
The data is seldom wrong or off, it’s just us humans that get in the way of it.