The multi-terrain, cross-country race sees entrants run in pairs around the brutal hills of The Lincolnshire Wolds with more than 800 feet of climbing.
From the start and finish in Swallow, near Caistor, the course took on some exceptionally difficult hills, mostly off-road using bridleways through woodlands, partially ploughed fields and along public footpaths.
The popular event attracted 223 teams of two including Paula Downing and Roger Blake who teamed up again and were first back for Mablethorpe in 40th overall in 1hr 48min 57secs.
Husband and wife Chris and Tammy Rainbow were 56th in 1.53.25, an impressive performance from Tammy after her recent return from a 15-month injury lay-off.
Sharon Wheatley-Margarson and Elaine Wilson have run the event together since it started in 2012 and finished 157th in 2.18.51, while Debbie Jinks and Andrea Mettam beat their 2015 time by more than two minutes, clocking 2.20.11 for 161st place.
In the event’s inaugural 10k, Janine Stones and Sheryl Hawse had a fantastic race as first ladies’ team, and fifth overall, in a time of 49min 35secs.
* A day later, Paula Downing took part in the Spires and Steeples trail from Lincoln Cathedral to St Denys’ Church, in Sleaford.
The name refers to the landmark spires of the churches and the rural sport of steeple-chasing.
The marathon was run over a tough multi-terrain course, mostly off-road and undulating, passing through many villages.
Paula was forced to slow to walking pace in parts by the driving rain which made boggy ploughed fields impossible to run on.
But of about 450 entrants, she completed her 71st marathon as second lady back in 4hr 16min.
* Sharon Margarson-Wheatley completed the East Coast 10k in 109th in 54min 10secs, while Zak Rowan, making his race debut, was sixth in the 3k fun run in a time of 14min 11secs.