He has held the record for a number of British long-distance trails, including the Pennine Way, and has represented Great Britain in the 100km road race.

[5] He was first in some of the Long Distance Walkers Association events, including the White Peak Hundred (mile) in 1988.

[15] In 1989, Hartley ran the 268-mile (431 km) Pennine Way from Kirk Yetholm to Edale in a record time of 2 days 17 hours 20 minutes, which he considers his most famous and most satisfying achievement.

[16] For his run, Hartley received awards for performance of the year from both the Fell Runners Association and the Bob Graham Club.

[1] He finished fourth in the European Championships in 6:37:45, which remains in the top ten of the British all-time road ranking list for the distance.