There is something I call the ‘xtreme goldfish’ phenomenon. Take something that works and it must work better if you make it more and more extreme.
Step was invented by a trainer named Gin Miller. She worked with Reebok. Something called ‘Reebok University’ was formed to begin doing research on step. Before they ceased to exist in the late 90s they had been on record with 128 as the upper limit for advanced participants.
I went back and looked at my 2007 ACE group instructor manual and found it said “According to Reebok Step Training Guidelines, beginners are easily and appropriately challenged at music speeds of 118 to 122 bpm. Safe cadences of 122 to 128 bpm are acceptable for participants at intermediate to advanced fitness levels seeking greater aerobic challenges.
There has been a lot of research since then, (as in a lot of things in fitness), and people in the business of certifying fitness instructors certainly keep abreast with this research, though may not agree on the results. ACE still, from what I understand, recommends staying under 128, though I have been told that AFAA suggests for advanced participants 135 is ok…. though I would be interested in having that confirmed.
Most premixed music today marketed for step seems to be between 128 and 130, though some goes up to 135…. but I have not seen higher. Some marketed for seniors primarily seems to be slower.
I remember back in the 90s when there was a lot of chat among instructors about step speed. The conversations tended to go “We are told to stay slow, but if I do noone comes to my class”….
I would have to say personally I feel safe at 128 or 130… I find beginners start to get confused if you inch up to 130, BUT you are more likely to confuse them if you try to teach too much too quickly, or do not break things down too much. I think 125 might be fine for beginners.
I guess I think though it feels good to go fast, there are other modalities where you have a repetitive movement that allows more speed with less risk.