The main purpose for training is obviously to get faster and stronger. Having a plan will help you reach that goal. Training without a plan, not knowing how much weight to use, the number of reps you should be doing and what you’re trying to improv, is like taking a road trip without a map. Your main goal is to improve on what you did before; that’s called progression. Any workout without progression means you’re not improving, which means you didn’t have a very good workout. Being able to see how you performed in your last workout, as far as your weight and reps, means you can easily set a goal for your next workout.