In 250 days, I will....

...be smack-dab in the middle of Ironman Louisville. Training for that day started today (technically, I've been building up my endurance over several years, but from now on, every training session is done with a purpose - to survive Ironman!). I'm using the 36-week Triathlon Dominator program designed by Ben Greenfield. Today is Day 1.

Today's workout had a very specific purpose, which was to determine my heart rate zones on the bike. I will use these zones to make sure that every time I'm on the bike, I am getting the absolute most out of that workout.

So here's what I did this morning:

30 minutes of weights while I waited for my watch to charge - I thought that it was charged when I looked at it last night...I was wrong. Not exactly the way I planned on starting my training for Ironman (IM)!

Once I had a decent charge on my Garmin, I hopped on the bike. I used a 20 minute warm-up to get my heart rate up and my legs loose. I then did a 40 minute time trail at a cadence of 85-90 rpm. I maintained a high intensity the whole 40 minutes, hard breathing and leg fatigue. I checked my cadence once every few minutes to make sure that I wasn't riding too slow. I hit my lap button on the watch 10 minutes into the time trail so that I could get my average heart rate for the final 30 minutes. This average heart rate is my bike lactate threshold (LT) heart rate. My LT heart rate is 165 bpm. I finished with a 10 minute cool-down. This was by far the hardest I've asked my body to work since the marathon...and it felt good!

Here's what the workout looked like:

So what do I do with this info? I'm going to use this LT HR to determine all of my new bike HR zones. The zones shown on the chart above are what I used last year after my VO2 bike test in November of 2009. In order to find my ranges, I take my 165 bpm and multiply it by percentages to get each zone. For Zone 4, I use 0.96 and 1.03 (96% and 103% for you non-math people). This gives me a range of 158-170. This is my new Zone 4 (LT or Anaerobic Threshold). Using this formula, I can find all of my HR zones. Here's what I came up with.

Zone 1 (Recovery): 115-125 bpm

Zone 2 (Endurance): 126-140 bpm

Zone 3 (Muscular Endurance): 141-157 bpm

Zone 4 (Lactate Threshold): 158-170 bpm

Zone 5 (Sustained Speed): 171-max

I'll do a similar test to find my run HR zones tomorrow. Should be fun painful!