The author was writing from the perspective of a runner [not surprisingly] in pursuit of a particular goal - in this case a specific time goal for a marathon. Her experience in working with a sports psychologist to overcome her "pre-occupation with time" [the end result], holds some reminders for education...
You don't control the end result [grade / test score / summative assessment judgement... ] - "You can only control the steps that improve your chances of hitting that... "
From an education standpoint, zeroing in on [desired] end results can too-often see these goals take on disproportionate importance, causing anything that doesn't appear to directly-relate to the achievement of the goal to be sidelined and neglected. For example, if a school wants to improve their literacy and numeracy results [novel, I know... ], overemphasising this end goal could see subject areas, knowledge and skills that don't appear to directly influence these end results, have their resources stripped, or be banished altogether.
Of course there is the other factor about how these goals, targets, etc. are actually measured - how well somebody is learning is certainly a lot harder to measure than how well somebody is running!
Another obvious side-effect of focusing too heavily upon the end result, at the expense of the ongoing process that leads up to the result, is that the learning is far more likely to happen [or should be] in the 'training runs' students are doing every day in classrooms, rather than the test or assessment task at the end of the journey. The runner / author wrote about the important mindset change she went through when she started using her performance information from her regular training [her kilometre splits... ] as feedback about how she was feeling, whether she needed to push harder and up her pace, or pull back to reserve energy, etc. Each kilometre, each training run, each week in the training program - all became information about how well or otherwise she was progressing towards her big goal [the specific time goal in her marathon race]. Grant Wiggins defines this concept of feedback in a lot of detail here - well worth a read.
So in schools, instead of feverishly chasing targets and goals that may not necessarily be the best measure of quality learning, we need to focus upon using the information we gather along the way about how students are performing and progressing, so that we can give good, timely feedback to them about their progress towards their own learning goals, as well as give them support, guidance and advice about how to continue to progress and improve.