I got a bit of a scare this morning. After strapping on my heart rate monitor, I headed down the road to leave the neighborhood. By the time I had gone a tenth of a mile, during my warm-up stage, my heart rate monitor read “80%.” Now, I’ve been using this thing long enough to know that I was not running in any way at an intensity that would have read 80% any other day. I was just warming up; if I had to guess, I think it would have read around 65% any other day.
What made this day unlike all other days?
There are three possible culprits in the wild reading on my heart rate monitor today. First, today was the first time I ran with my new running jacket, a Patagonia Runshade 1/4 Zip. It would be unfortunate if the jacket is interfering with my heart rate monitor, since I like the jacket a lot -- but this is a likely cause. My hope is that the error was due to a failing battery in the chest strap. The battery is easy to replace and would require no further change of gear or routine.
The third and worst case scenario for the cause of the error is that I had the wrong resting heart rate programmed into my heart rate monitor. The Garmin (HRM) wants to show zones as percentages of the differential between maximum heart rate and resting heart rate, while Coach Benson expresses all of his zones simply as percentages of maximum. In my case, my maximum heart rate is 200 and my resting heart rate is 50. If I put both of these numbers into my Garmin, it will tell me I’m at 70% when my heart rate is (((200 - 50) * 70%) + 50) = 155, while my training program would mean 70% as (200 * 70%) = 140. To get my Garmin to read in Coach Benson’s terms, I set resting heart rate to “1.” Therefore the differential is essentially the same as actual maximum heart rate. I’m sure that I’ve set my device accordingly in the past. But yesterday I noticed that the value for resting heart rate in the computer software related to my Garmin was set at 55 or something. I changed it so that the charts would read the way I want them to. But the question remains: Was my device also set to RHR = 55 over the past few weeks? If so, I’ve been going too fast all along -- even as I’ve experienced my running as, at times, maddeningly slow.
Notice how I’m not concerned that my heart was different today than yesterday. I am confident that there is, for some reason, an error in my tools or their use. My heart is as good as it has ever been.
Thinking about this leads me to ponder the words of Jeremiah in scripture: “The days are coming, says the L-rd, when I shall establish a new covenant with the people of Israel and Judah. It will not be like the covenant I made with their forefathers when I took them by the hand to lead them out of Egypt, a covenant I broke, though I was patient with them, says the L-rd. For this is the covenant I shall establish with the Israelites after those days, says the L-rd: I shall set my law within them, writing it on their hearts; I shall be their G-d, and they will be my people. No longer need they teach one another, neighbor or brother, to know the L-rd; all of them, high and low alike, will know me, says the L-rd, for I shall forgive their wrongdoing, and their sins I shall call to mind no more.” The New Testament book of Hebrews explains that, indeed, the time of the new covenant has come -- that it took effect on the death of Jesus, ratified by his spilled blood.
The Christian understanding, then, is that we have knowledge of perfection written on our hearts. Does this mean that we are to go wherever our hearts lead us? I think not. Though the perfect law of the L-rd is written on our hearts, I think there’s a lot of other stuff written there, too. The very concept “follow your heart” can lead one down some very dark and clearly sinful paths very quickly. Adultery. Greed. Idolatry. These can all be seen as examples of the manifestation of following one’s heart.
When we want to know more about our physical heart, we use tools. From a stethoscope, to a heart rate monitor, to an EKG, tools can help us better understand how our hearts are functioning. Still, any of these have their limitations. I bought a med school stethoscope for my two-year-old son so that he can hear his heart beating. But if I just hand it to him, the chances are slim that he will make good use of it. Even putting the eartips in his ears & the diaphragm in his hand, he is unable to be able to use the stethoscope correctly. So, too, if you were to wheel a state-of-the-art electrocardiograph up to my desk, I would be unlikely to be able to learn much about my heart with it. Just as Josiah would need some help to use the stethoscope to hear his heart, I would need instruction to make any use of the electrocardiograph. We need both good tools and knowledge on how to use those tools if we want to be able to listen to our hearts. But as I learned this morning, even a good tool that I know how to use can let me down.
What we need is a perfect tool and complete understanding of its use.
To know our spiritual hearts, I think that we do indeed have a perfect tool in The Bible. But do we have complete understanding of its use? The scripture I quoted above says, “No longer need they teach one another, neighbor or brother, to know the L-rd.” How do we learn how to make the best use of our tools, then? Do we really need no assistance in understanding The Bible? Jeremiah is prophesying that we, in our time, have the perfect law written on our hearts. My understanding is that The Bible is the perfect tool. So, does this mean that what we have is sufficient for a total understanding of G-d’s perfect way?
Though I will change the battery on my chest strap today, I probably won’t run with my jacket on tomorrow. So tomorrow I should know whether the worst-case scenario -- that my resting heart rate has been set incorrectly -- was to blame for the peculiar HRM readings today. It’ll be Sunday or Monday before I will know whether simply changing the battery has fixed my problem. If it works well tomorrow with a new battery & no jacket but then fails on Sunday, then presumably the jacket is to blame. Here’s hoping that a $2 battery is the worst of my problems!
No comments:
Post a Comment