A moving average: how it can save your sanity

 The scale will not assess your moral fiber.  It doesn’t indicate that you are a “pig”, “slob”, or “hopeless”. Similarly, it doesn’t tell you when you’ve gained power or strength or a healthier future.  I often say don’t look inside the fridge for company, for love, or for entertainment. All that’s in there is food.  And don’t look to the scale for a fitness, health, or athletic appraisal, please. It only reads weight. 

(Imagine if we gave our height as much meaning as our weight? Would we be embarrassed to tell someone our height? Lie about our height? Would we read magazine articles ad infinitum on appearing taller, or dressing taller? Would we clench our jaws when the doc wants to measure our stature?)

One of the limitations of scales is the “fickleness” of the readings. The contents of your belly, the amount of clothing you’re wearing, your hydration status etc. all influence the number. So the individual readings don’t mean much. But since we want slow weight loss, how do we know when the small changes are actual progress or just day-to-day variation? 

I’m no statistician, but let’s explore a moving average here.  The average of your daily weights over the last week, for example, is a pretty good assessment of your actual weight. It would likely include one extra-heavy day (Chinese food the night before, perhaps) and one extra-light day (dehydration after a run…or beer run). But the average evens it all out, and is more accurate than any single number.  Let’s say you calculated your average weight for the last week, and then calculated it again for 7 days next month.  Comparing the two averages would be a better way to judge than hopping on the scale once this week and once next month. And it’s less confusing than weighing every day and being overwhelmed by all the little variations that obscure if anything real is happening. 

To calculate a moving average, each time you add a data point, you drop the oldest one. The moving average over time can either go up or down, and it’s the best way to judge if you’re actually losing, maintaining, or gaining weight. One great online gadget is the Google 15.  This tool automatically calculates a moving average for you, and explains well why the moving average is good for judging your progress. It makes the trend clear, so you don’t get thrown for a loop over the day-to-day fluctuations. If you’re a daily weigher, I’d definitely give it a try. It can lead to a healthier mindset by encouraging a long term view of progress.

Bonus: it gives you little messages to congratulate you when you’re moving towards your goal, and warns you when you’re moving away from it. Just please, remember…it’s just weight! Not bodyfat, speed, or agility. Though a moving average would also be a fun way to any of track those things too! Maybe I’ll track my moving average for pullups…..