Andrew Rivett is widely credited with the fastest JOGLE/LEJOG on foot. See:
"The fastest ever run between John O'Groats and Land's End was 9 days 2 hours 26 mins by Andrew Rivett (GB) from 4 to 13 May 2002. Incredibly, he never covered less than 144.8 km (90 miles) per day (except for the final day), and on the sixth day managed 157.8 km (98.1 miles). He ran for an average of 18 hours per day."