Last week you completed eight repetitions; this week you completed twelve. That may represent progress, but the comparison is less clear if the movement became much shorter. A training log becomes more useful when it records how the repetitions were performed as well as how many there were.
The NHS’s strength-exercise guidance emphasises controlled movement and gradual progression. The appropriate movement range depends on the exercise and the person; this is not a reason to force every joint into the largest possible range.
Choose a repeatable description
For a sit-to-stand exercise, chair height is relevant. For another movement, a coach may help define a comfortable start and finish position. Record those details in plain language so that the next session uses a comparable setup.
Include meaningful changes such as a different bench, support or exercise variation. A heavier weight with a shorter movement is a different performance, not automatically a better version of the earlier one.
Keep the record proportionate. You do not need a laboratory analysis for every session. One note such as “same chair, controlled lowering, no arm assistance” can explain more than a bare repetition total.
Use the log to ask better questions
If the range becomes difficult to maintain, discuss technique, load and fatigue with a qualified professional. Pain, a recent injury or a medical condition may require individual advice. Do not use the notebook as a reason to push through concerning symptoms.
Consider an illustrative comparison: ten controlled repetitions at a consistent setup followed by eight at the same setup the next week. The lower number is information about that session. Changing the movement to reach eleven would hide the observation rather than explain it.
A consistent log makes progress easier to interpret over time. It can show that control improved, assistance decreased or the same work felt easier, even when the repetition count stayed unchanged. The purpose is a clearer picture of training, not a competition with the previous line on the page.