Heart Rate Monitor

Harrow

Lenny,

You're obviously new to using a heart rate monitor for training and racing. Your MHR is a fixed variable. Do an easy warm-up run for a mile or so, and then run up a steady incline for about a quarter mile as fast as you can. The maximum bpm that you get doing this will be a fair indication of your MHR.

Then when you train, you use % of the MHR to set specific training goals. Just about any modern fitness and training reference will talk all about this. I encourage you to read a few articles on this.

Typically, for a longer distance triathlete, you would only spend a small amount of time training above 90% of your MHR. Perhaps one session in each discipline a week.

Easy recovery runs/rides may be around 60-70% of MHR, and endurance building runs would be between 70% and 85%.

Over a short running event (say, 10km), I use my heart rate monitor to regulate my speed, especially on a new course with a lot of hills. I know that I can sustain 190 bpm over 10km, so I set my upper limit alarm to this figure, and it lets me know when I need to slow down. (For example if I go out too fast due to the adrenalin rush at the beginning of a race, if the incline increases gradually, or if I am trying to keep up with someone who is really going too fast for me, etc.)

In a long triathlon, you use your heart rate monitor in a similar way, although it is even more important, because you are using it to regulate your energy usage. For example, on a half-ironman distance, I set the alarm to around 170 bpm. If I go faster than this on the bike leg, I will burn up too much carbohydrate and will 'bonk'. By staying below my limit, I use more fat for energy and save my legs for the run, allowing me to finish the race.

MHR's and sustainable HR's vary greatly from person to person regardless of fitness level, so you'll need to determine your own from experience over time. If you used my figures, for example, you'd probably crash in the first 2km, because for some reason my MHR is about 20 bpm faster than average, even though my resting HR is around 50 bpm.

Your heart rate measurements can also be a great source of motivation. I keep records of every run and ride I do, and it is good to see progress where, for instance, you see your average heart rate drop for a particular distance and time. This can also be a good indicator for when you need to let yourself rest, for if your average heart rate is unusually high for a particular distance and time on a familiar course, then you may be fatigued and need to take some easy days.

Regards,
Harrow.