As an accountant Tim Evans has always had a good head for figures – and for his latest challenge the magic number is three.

The 47-year-old sets out today in a bid to tackle a trio of marathon distances, around 78 miles, in just three days.

He will walk the challenging Dorset coastal route, which includes the Studland sands and tough Lulworth hills, as he attempts to raise £1,000 for charity.

Tim from Stoborough, near Wareham, is hoping the recent stormy weather will not hamper his progress.

He is raising funds for the Weymouth Riding for the Disabled Association charity, which caters for schoolchildren with special needs, including youngsters with cerebral palsy and autism. Tim said: “It can take up to three volunteer helpers per horse, one to lead and two side-walkers.”

Visit justgiving.com/tim-evans-RDA to sponsor Tim on his Lyme Regis to Studland trek.