I ran today. For the first time since the Mud Run. It felt strange yet comforting at the same time. Strange in that I was no longer running to train for the Mud Run, no longer wondering if my workouts would help me prepare adequately for the event and because I have two new goals to pursue. Comforting, well, that's an odd word to use for a run but it was just that. It's like getting into an old familiar habit.
Anyway, one thing I noticed was how quickly my heart rate dropped off during the rest part of my intervals. First, the stats:
Avg HR: 145
Max HR: 181
Now, this includes the five-minute warmup. Without that my average heart rate would have been a little higher. Regardless, after running rounds of 6.0 and 7.5 for 12 minutes - the longest portion of my run - I went from somewhere around the low 160s to the one-teens in just over two minutes. This is a tell-tale sign that the interval run is not challenging enough - at least, that's what I've read and been told.
The formula is somewhat simple. Take your max heart rate (187) and subtract your resting heart rate (50 or thereabouts). 187 minus 50 is 137. Divide that by half (68.5) and add that back to your resting heart rate (118.5). If you get below that heart rate during intervals, then your workouts aren't as challenging as they could and should be.
Of course, this means that I need to amplify my workouts. I can still use this interval run and frankly I'd be upset if I couldn't. But instead of a 6.0 and 7.5, perhaps I can do 6.3 and 7.8. It's a little modification but it will go a long way, I'm certain.
After my next rounds of running, six minutes of 6.0-7.5, my heart rate went down into the low 120s but between four minutes of rounds and a two-minute sprint, it stayed at around 150. I'd expect that since by that point I'm usually exhausted. I sprinted two minutes at 9.0 and then walked five minutes afterward.
Then to round out my cardio, I biked for 20 minutes. I didn't keep track of the heart rate on my watch but since my heart rate monitor and the bike (and mill for that matter) are all made by Polar, it continuously displays it on the bike. I stayed around the mid 130s and got up to the high 150s during my most grueling part, the final four-minute stretch.
Oh, and one more positive from today. My shoes are fine. I used my running shoes during the Mud Run on Saturday and they looked in bad shape afterward, drenched and covered in mud. But I hosed them down, let them dry and put them on. They had some sand in them which I expected and felt during my interval run today. But I don't feel any sort of remnants right now.