My Top 10, many of which would work better outside at some school bleachers rather than somewhere with a single set of stairs:
1. Inch worm up the steps.
2. Staying on all fours, complete a Pushup every step.
3. Hop, then squat on each step.
4. Stagger Squat Each Step (one foot on higher step than the other).
5. Run up 2, down 1, repeat until finished.
6. Combination move with every step (such as carrying dumbbells and completing a press or arm curl every step).
7. Race a partner, winner holds extra weight in hand (I like medicine balls for this because they are easy to drop if necessary) for next round, until one person wins with the heaviest weight.
8. Skip a step with one leg only, repeat next round with other leg (takes coordination).
9. Ladder up steps (up 1, down 1, up 2, down 2, and so forth).
10. Play “Glick Says” – like Simon Says except give commands to change movement or direction. When you’re ready for them to finish or move to an activity different than stairs give them a false command but don’t say “Glick” which clues all participants to sprint to a designated location.
Great answers and ideas. The forward lunge step, two steps at a time, is obviously a classic. The suggestions for a side step up with a finishing kick are quite clever. And, of course, triceps dips are integral. I also suggest you have your clients perform push-ups with their heads facing down the stairs, feet on a step up and behind.