Hi Lisa. A lot depends on the senior(s) involved. Like any other age bracket, people classified as “seniors” come in all sizes, shapes, and fitness levels. Also, the program you use may (probably will) also depend upon the age of the seniors. It’s funny that as our population gets older, and as people live longer, our definition of “seniors” hasn’t necessarily kept up with those demographic changes. In some circles, anyone over 50 is considered a senior, so your program will/should reflect the age-range as well as fitness level of your group.
I hope that this helps.