I did a little research this week and thought I would share what I found about using your heart rate as a training tool.
I got in a long run of 6.65 miles on Sunday. I did it at a slow pace of 10:50 per mile average. I was shooting for 11 minute miles thinking that would allow me to keep my heart rate lower than usual around 140 bpm to start out. I know I was on exactly 11:00 miles at 3.1 miles, so I actually ran a negative split of about 17 seconds per mile pace the rest of the way and it included a slight uphill section about a half mile long. I was worried a little about having sore legs Monday and even today, but then I read a post a coach wrote about sore legs and it made me feel better: http://running-advice.com/blog/?p=31
I just got so used to running all out last year as I did most of my running at lunch in a group that was faster. It is hard for me to run at this lower heart rate because I feel so good I have the urge to speed up. I must have glanced down at least 10 times during the run where I saw my hear rate in the 150’s and forced myself to slow down. Since I didn’t have anything to drink my heart rate naturally drifted up. That is the one thing about heart rate training that has always bothered me a bit since I didn’t know why. Recently though I read an article that explained why. It was in a magazine that I cannot recall. I found a few articles online that also explain the various things that affect your heart rate as you work out. So when you use heart rate as a tool for training you need to know these things so you know why it might be acting differently.
- Cardiac drift: Heart rate goes up because sweat mainly comes from the fluid in your blood so the decreased volume of blood means your heart has to beat faster. (fifth item in the article: http://runningtimes.com/Article.aspx?ArticleID=6627 )
- Heart rate goes up as your body temperature increases, which happens during exercise. http://findarticles.com/p/articles/mi_m0675/is_4_20/ai_90924147/
- Heart rate goes up as ambient temperature and humidity increase so you will have a higher rate on a hotter or more humid day even if you do the same workout. This and the last item are obviously tied together and are described on the link as above.
- Another item that is something to watch once you use heart rate monitoring for a while is that when you get sick your heart rate increases. So if you get in the habit of checking your resting heart rate in the morning before getting up and notice it’s higher than normal it might be a sign your body is working on something. Maybe you sleepwalked at 3 am to get a PB&J or maybe you are getting sick, maybe you woke up dehydrated, or maybe you are training so hard that you did not recover overnight. You cannot measure this a few times and get a clue. You will need to keep a watch out over time.
- Another thing to note about heart rate is that your resting heart rate will decrease as you get more fit. Mine went from around 60 to about 45 so far. Also the recovery of heart rate to normal levels after working out happens faster as you become fitter for the same length and intensity of exercise.
For more info on training in heart rate zones try this link:
I have decided that I trained to intense all the time while running last year, so I will be doing a lot more less intense stuff. I am starting a little later than I should be as this is what is considered base training, but I will just not run the races too intense and get a worse time than last year but then enjoy the rest of the year without the same injury.