6by1k r20 - nasty start to the day

6 by 1k at rate 20 - 2min 30sec rest - I looked back at my 2by4by2:30 r30 session (29th May) which came in about 1:38.5 but with a last split of 1:36.6 I figured 1:37 might be a good starting point and I think I got it about spot on - tough - sweaty - got the HR up and had a few lung rattles towards the end - glad that's done

Garmin HR Details