Here’s why I love checking blood sugar and ketones. Testing blood is to training with a power meter what looking in the mirror and checking weight is to training with a HR monitor. Let me explain...
rate (and thus the monitor) has a built in, inherent delay. Like if
you’re relying on HR and want to keep it at or below 155 -- you start up
a steep climb, keeping HR below your threshold, then you get to the top
and are shocked to notice that on the way DOWN your HR is up in the
160s. That’s because there’s a slight delay. So it's a bit of a guessing game...
Now, when you have a power meter and climb a hill. There’s no delay. You know EXACTLY what kind of power you’re putting out the SECOND you’re putting it out. Basically, it’s a better indication of your output.
Relying on the mirror and scale is great. Nothing wrong with it. But after a day or weekend of eating “terrible”, I may look the same and weigh close to the same, but I don’t really know what’s going on inside my body. I could think, “well I guess yesterday’s binge on raw cheese and meat didn’t have an effect on me so I can be a little more loose with my eating.”
If I start to loosen things up, before you know it, I’ve gained 5 pounds and start to look puffy. Which could have all been avoided had the “look test delay” not been in effect.
Blood glucose and ketones allows me to see what kind of huge effect yesterday’s menu had on me. So now, instead of thinking everything is fine and normal, I can dial it back in before any real “damage” is done. And by damage I just mean damage to my goals...not any sort of real nutritional damage.
So the blood meter lets me avoid the week or so of time that will go by before I notice a change, and the week or so of time that will go by to turn it back around...that’s a big deal.