A real notebook made of real paper, with a real pen or pencil.
You want to make sure you're progressing each workout. If you are, that puts you in a positive feedback loop that boosts motivation. If not, you'll know exactly where you're stalling, and have a good idea of how to work around it based on your progress or lack thereof in other lifts. (If you're dieting down to lose fat, stalls like this are expected, so just grin and bear it until you're done losing fat.)
It doesn't have to be obsessive. All you really need to write down is what you plan to do that day and what you actually did in the session. Any more is optional and probably not necessary.
You'll also want to log your food intake, including portion size (in weight, ideally) and dividing the day's intake by feeding/meal. If you follow a set meal plan, as I do, you don't have to do this -- though if you cheat, you do need to include that in your log.
You want to make sure you're progressing each workout. If you are, that puts you in a positive feedback loop that boosts motivation. If not, you'll know exactly where you're stalling, and have a good idea of how to work around it based on your progress or lack thereof in other lifts. (If you're dieting down to lose fat, stalls like this are expected, so just grin and bear it until you're done losing fat.)
It doesn't have to be obsessive. All you really need to write down is what you plan to do that day and what you actually did in the session. Any more is optional and probably not necessary.
You'll also want to log your food intake, including portion size (in weight, ideally) and dividing the day's intake by feeding/meal. If you follow a set meal plan, as I do, you don't have to do this -- though if you cheat, you do need to include that in your log.
