He finished second in the English national cross-country championships in 1907 and showed sufficient form in track races during the early part of the 1908 season to be selected to race in three events at the Olympic Games. Deakin won his first round heat of the 1500 metres event with a time of 4:13.6. Despite being one of the slowest first round winners, Deakin won by seventy-five yards. His time in the final was better, though he still finished sixth at 4:07.9. The next morning Deakin led the British team home to victory in the 3 mile team race. After a celebratory lunch, complete with champagne refreshment, he lined for the heats of the five miles competition. Unsurprisingly, he dropped out of the race before the finish.