Weight-Loss Monday!

It’s Weight-Loss Monday, my hopefully weekly blog post about how my weight loss is going, and the experiment to judge the whole “food in, exercise it off” thing that we’re told.

Some notes on how I’m doing this: I’ll get up, calculate the miles that were ridden and approximate calories expended using the data from MapMyRide.com as recorded from my bike computer. I will relieve myself, then weigh myself, and record the result. Then I’ll write a post about it! I will try to do this every Monday. The details are at the end if you want to skip the methodology part.

From week-to-week, there could be considerable variability. Stuff like water retention, undigested food, etc., will vary over short periods of time. But. . . since what I’m trying to record is the efficacy of the system, over time, it’ll even out.

Another significant artifact is that, well, weight loss doesn’t automatically target fat. A person’s body will sacrifice muscle mass before fat unless they’re also doing vigorous exercise. Which is why I’m doing this, now! I am vigorously exercising! I have the data to prove it! If anything, for quite a while, I should be gaining muscle mass because I’m hitting the biggest muscles in my body with a lot of exercise. (And if I am gaining muscle mass, well, I should lose weight even faster – because it takes energy to build that muscle, too. If the body is “just” a system where energy goes in and out according to a flat formula, given the second law of thermodynamics, the body can’t add weight for free. It has to convert mass inside the body into muscle, which expends energy, so gaining muscle mass will not inhibit weight loss by conventional reasoning. Of course, I think the truth is more nuanced, thus my self-experiment.)

An additional note about calorie-use estimates. I’m using the calorie calculator with MapMyRide.com. I’m not using a heart-rate monitor (which I might get in the future), much less something like a power output meter (which can set you back $1500, so, yeah, no). When attempting to estimate calorie use, well, that’s part of the problem, right? People say, “Doing this exercise uses X number of calories,” but there are no non-invasive ways of measuring the truth of such statements! Yet, that is the standard. Doctors and nutritionists say that if you do “this many calories of effort, you get this amount of reward.” If we’re unclear at what the unit is, though, how can we make conclusive statements about the results? However, I will look for a correlation: if I find that every 7000 calories, for instance, loses me a pound of weight, I’ll note that.

According to my research of online calorie calculators, MapMyRide’s calculator is somewhere in the middle (though the lowest ones didn’t seem to take air resistance into account – the amount of calories burned for a ride at 20mph was exactly twice that at 10mph and that ain’t how it works). The estimate is also a gross simplification – though that doesn’t bother me. In the long run, I start and stop at the same place, so elevation is a wash, and while I know the second law of thermodynamics means that I will never get back all the energy I “save” going downhill, bikes are reasonably efficiently. The wind tends to blow in my face and back equally. I suspect the environmental factors are minimal in the long run.

Indeed, I find myself somewhat confused by what a calorie is, biologically speaking. In physics, a calorie is the energy required to raise a cubic centimeter of water one degree Celsius at sea level, about 4.2 joules. But no one is arguing that a person uses calories like a physics problem. One’s level of exertion plays an enormous role.

So, just today, Adrienne and I rode our bikes to a sandwich shop and got dinner. Since I’m testing bike apps for my phone, I measured it. We were surprised that the relatively short ride supposedly used 350 calories. That’s two cookies! We took the ride leisurely, though, at an average speed of 9.2mph for about half an hour. I only “exerted” myself going up the hill to the house, primarily because I’m working on developing a higher cadence.

Yet, energy was indisputably used. A year ago, I would have felt that ride. It wouldn’t have been hard, but I would have felt it. I would have found it easy to believe that I used 350 calories. Do I use fewer calories because I feel them less? Physically, fit or unfit, one uses the same amount of calories to move the same mass the same distance over the same period. As a physical system, the cosmos is indifferent to how hard your heart pounds, or if you don’t sweat it. It costs the same number of physics calories to move 100kg over 10km in one hour – fit or unfit. But your body feels it differently.

Anyway, the stuff about my weight and shit: Since I last weighed myself, ten or eleven days ago, I have ridden 162.99 miles (it was, apparently, a busy eight days since I wrote the first post) and burned approximately 17,532 calories on those rides. That’s almost exactly 5 pounds of fat I should have burned away, even ignoring that I already “should” be in a calorie deficit, not to mention stuff like gardening I’ve done in that span.

My weight loss during that time is 2.5 pounds, which is also my cumulative total. This is almost exactly half of what I would expect if the human body were simply an energy system. Of course, over this short a time, there will be considerable variation, and 2.5 pounds in ten days is great, but I rode 162.99 miles!

We’ll see where it goes from here!