Taking the initiative to commit to an objective of physical activity is demanding and intimidating. It requires some confidence and training, both mentally and physically. A pledge with yourself to withhold the challenge.
To endure in a long distance outing makes for complete uncertainty. Will things remain this way in 10 miles? 10 minutes? 10 meters? The initial steps feel glorious and freeing. Your motion feels relaxed and natural. Your mind is at ease, you drift from thought-to-thought easily while day-to-day stressful implications are no longer relevant. Pushing feels easy, your goal feels completely obtainable.
Throughout time on your feet, you begin to wane. Fatigue sets in. Your goal that felt close earlier in the day now feels even further away. You take 10 seconds to walk, then 20, then 30. You fight back the urge to give in and stop. The commitment feels like its slipping through your fingers, but you hold true. Nothing is barring down on you or holding you back. You continue to the end.
Completion offers fulfillment and agency. Those continuous thoughts of stopping are lifted. You've settled your commitment. The mind eases back to how you felt at the beginning, reflective and happy to be done.
…Dammit all if you don't feel as though you could keep going.