<p>My own little slice of hell. Dreaded Airdyne intervals. Four 1/2 mile sprints, recovering in between with an easy pedal until my heart rate fell back to below 70% of my max.</p>
<p>As I promised myself, I wanted to kick it up a notch. So I changed into shorts and a t-shirt (brrrrr) and put a big fan at chest level blowing on me from 2 feet away. And, kept my eye on the display, trying to hold my pedal RPMs up – ideally above 72 rpm, although they slipped a few times to 70 when I was gassed just hanging on.</p>
<p>Yippee! A new personal record, eclipsing my previous best average RPM by 0.5 rpm for the four half miles. A solid 5 rpm gain from the last time out on this workout last week.</p>
<p>The Airdyne is a brutal machine when you try to push it. Because it’s air resistance, the energy output increases with the square of speed. So going a little faster is a big increase in energy. I saw a heart rate on the final interval of 98% of my max. I think I’ve only seen a higher heart rate on the Airdyne twice - once on my previous PR. </p>
<p>Crazy. Just 5 minutes 17 seconds of actual sprint and I’m toast.</p>
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