Did I manage to do it? Yes, I did. Managed to attend all 3 classes (BodyAttack+BodyPump+BodyStep). Not a big deal actually, Body Attack was a shorter class of 45 minutes (where Track 8-Interval Training and Abs are excluded) so it felt more like a warm-up class for me. Continuing with my experiment with the TIMEX HRM, heart rate averaged at about 65-70% with a peak at about 85-89% towards the end of the last power track. The mediocre HR is also probably due to the fact that it was the 1st class of the evening so the studio was reasonably cold (I hate it when that gave me goosebumps). But darn, I kind of "mis-stepped" a little, causing a little sprain to the "bridge" of my left foot (the area between the arch and ball). That happened before and it could be quite a pain in the neck in the sense that it could be persistent and be a hassle when doing high-impact exercises (e.g., BodyAttack and BodyStep).
Next was BodyPump. Nothing extraordinary to mention. Average HR zone was in the 70-80% region (probably some were in the 60-70% region), highest was during the Back track, probably because I increased my weights during the last 6 lifts. Upper body felt a bit tired at the end of the track, particularly the shoulder.
Last, was BodyStep. By now, body was a little fatigued due the fact that muscles were already worked out during BodyPump. And true enough, the little "sprain" that occurred during the earlier BodyAttack class started to bother me a little but it remained hardly noticeable until the "gallopping" in the "Speed" track. Today's HR was not as high as the other day, although mostly was still in the 70-80% region with the max at about 169-172 bpm. But what I can conclude is not to underestimate BodyStep. It is easily on-par with "powerhouse" programs such as BodyAttack and RPM especially if you take on the challenge of increasing the step board to the highest level*.