Step by step

1. Open the exercise and tap Edit.
2. Change what you need: name, target muscles, goal, the pace slider, ranges, sets, effort or rest. A muscle you search for and don't have: Create “…” opens New muscle with that name; pick its group (filled in for the usual ones) and tap Add muscle to come back with it ticked.
3. Each change saves by itself (the note at the bottom says Saved, or what to fix). The plan is rebuilt from your latest logged session. Tap Done when you're finished.

• Pace: how much stronger (or longer, or faster) each session aims to be. The line under it shows the sessions to go as you move it. 0.3–0.6% is steady for most people.
• Changing the goal keeps the pace, so a harder goal simply takes more sessions.
• On adaptive exercises, pace, effort and the goal also change by themselves as you log. Whatever you save here is where they carry on from. Adaptive plans →
• Delete an exercise from the bottom of its page. Its history goes with it.