Taryn Plumb

The three women grimace and groan as they lower into their 20th — and final — triceps dip.
Then, without pause, they pant through the wet grass at Boxford’s Boy Scout Park to a set of metal bleachers with weeds poking through the slats.
Instructor Robin Beardsley gently urges them on, "If you’re tired, take it easy," then counts their progress up the steps: &qu…