Peak productivity requires that you intentionally direct your attention to the most important things at the most effective times. The less intentionally your highest impact efforts are planned and promoted, the more likely you are to focus on what is least important.
Not all action is equally effective. What you are doing, how you are doing it, and why you are doing it matters so much more than just whether you are doing something or not. If you want to achieve peak productivity, you will have to learn to optimize what you do, how you do it, and why you do it.
Productivity is not a question of activity, but impact. Counting hours is much easier and much more consistent than counting actual production, but reality is not directly effected by the amount of time that you commit to a task. Busyness is not progress. Those who conflate productivity with activity are assured to have a dramatically lesser impact than they otherwise could because they will prioritize additional time and effort as its own benefit instead of measuring the outcomes that actually matter. Satisfaction comes from impact—not activity, and not number of activities. Always focus on what has the highest impact. Focus on outputs, not activity.
Even hard work is no guarantee that you are advancing your purpose as much as you would some other way, if at all. Examples abound where less time on task under the right circumstances can yield dramatically better outcomes than more time would. Effort is only progress when it advances your purpose, and does so more than any other possible action.
Prioritization is the key to knowing what to say no to. Focus is a question of saying no to everything other than what is most important. You have to learn to say no to the things that matter the least in order to have the time to do what matters more.
Productivity requires that you orient your actions most directly towards your purpose. You will be most productive as you navigate the opportunities and obstacles in the landscape of your life as you would using a compass to head due north in the most efficient way given terrain features on a map.