1/ I joined a gym >3 months ago and started up with my old routine of 1 day on/1 day off, upper/lower split, doing slower reps at lighter weights to failure, like I learnt from @mangan150 a few years ago. I was hospitalized with pneumonia 2 years ago, which set me back a lot.

2/ I used to also do HIIT, getting my pulse up to 160/94% of theoretical max. After the pneumonia, I'd struggled to get it >145. A cardiologist recommended I resume regular HIIT over a year ago to aid recovery. I failed to do so.

I also switched focus to
strength/hypertrophy

3/ as I'd lost some muscle. That led me to cut HIIT entirely, on the advice of gym staff and Twitter folk.

My lifting regimen has been 1 warmup & 2-4 work sets. I feel I've been progressing and have been adding weight over time. My squats feel limited by my CV system though.

4/ So I decided to add HIIT back to leg days to train my CV system. I did 7 sets of v-squats yesterday, ramping up to 360 (very heavy for me) and back down to 2 "burn out" sets at 180. This video's of the previous leg day's 360 set, to give an idea of my approach.

5/ The last 2 sets at 180 were like this video, also from the previous session. I found my pulse to be 152-156 after the last 2 sets, which was very gratifying. That showed my CV was improving, and my squats were really intense, as I'd hoped they'd be. I did hip ad- & abduct,