A training log answers a practical question: what should you do next time? You do not need a complicated app or a spreadsheet full of formulas. A few consistent notes can make your sessions more deliberate and help you avoid guessing at the weight rack.
Record a useful baseline
For each exercise, note the variation, weight, sets, and repetitions. Include the equipment setting when it changes the movement. A cable row with a different handle or seat position may not be directly comparable to your last session. Consistent names make the record easier to read later.
Add one brief quality note: controlled reps, rushed setup, or a load that felt harder than expected. Keep it factual. You are collecting information for your next decision, not grading your character. If a session was shortened by work or travel, write that down too.
Make one small change at a time
Progressive overload means increasing the training challenge over time. ACSM describes gradually progressing resistance, while NSCA connects progression with proficiency in the movement. Adding weight is one option; completing another well-controlled repetition within your planned range can also be a useful step.
For example, imagine a familiar exercise with a planned range of eight to twelve repetitions. Record what you actually complete with the intended technique. When the top of that range becomes manageable across your planned sets, consider the smallest practical load increase. Keep the exercise and setup stable so the comparison remains useful.
Read the pattern, not just one number
Not every workout needs a heavier weight. Repeating a session can help you practice a movement and confirm that the previous performance was repeatable. If your setup changes or your repetitions become rushed, the number alone does not tell the whole story.
Once a week, scan your notes for a practical next step. You might keep the load, adjust an awkward setup, or ask a qualified trainer for feedback. Change one variable before rewriting the entire routine. Your log should make the next workout clearer, not pressure you into a personal record when the session is not going well.