Some background information about rocket yoga and my general level of fitness first. 'The Rocket' is a fast paced practice with plenty of inversions and challenging sequences which initially seem absurd but quickly become addictive. I've been practising rocket about 2-3 times per week for a few years and qualified as a teacher last summer, but I would describe my practice as 'approaching competence' rather than 'advanced'. I used to do triathlons and play football, but these days yoga and cycling to work is the only exercise I get. My resting heart rate is around 50 beats per minute (bpm), which is apparently pretty good (i.e. low) for a 36 year old.
How hard am I working here? Well, pretty hard. My aerobic zone (about 120-145bpm) can be considered 'moderate' effort and I'm there for around 14 minutes. But I spend 28 minutes working 'hard' (in my anaerobic zone, 145-165bpm) and nearly 3 minutes working 'extremely hard' (the red speed/power zone, over 165 bpm, or 90% of my max heart rate). I burnt 760 calories, even though I spent the first 9 minutes doing very little and the last 10 minutes lying on my back. In short, it was a proper workout.
You might be wondering what I was doing at the peak? Well, although handstand and some other arm balances got my heart rate up, you can see about 90 seconds into the clip below it was a relatively innocuous looking pose that had my heart pumping the hardest.
I don't know if my heart rate climbs in Anjaneyasana because I'm back bending, because it's towards the end of the standing sequence or because my arms are above my head and I have tight shoulders. I also don't know what the data would look like for someone with more or less yoga experience, or how it compares to other kinds of exercise for a similar period of time. This is all stuff I intend to write about in future posts.