variable-speed belt grinder. Apparently, disused fitness devices make an ideal framework to build your own tools: Strong metal frames, plentiful adjustment guides, and strong treadmill motors.

“The mental adjustment is probably just as important ... which can feel discouraging at first. The rotating belt on a treadmill helps with leg turnover, which can make your runs feel a bit ...

“They let me adjust speed easily ... recall of the larger ’mill because it has a shorter, more standard treadmill belt rather than the smooth rolling slats (similar to those on Woodway ...