What do the W, F and D letters mean?

They are set types. You pick one on a set while you log your workout, and the letter takes the place of that set's number.

• W: a warm-up set. It is not counted in your set numbers.
• F: a set taken to failure. It still counts as a numbered set, and shows the letter in place of the number.
• D: a drop set. It also counts as a numbered set, and also shows the letter.

A set with no letter is a working set. Most of your sets are working sets, and you do not have to tag anything.

A set type never changes your XP or your stats. It is a label, so you can look back later and see what each set was.

Learn more: Do warm-up sets earn XP?