In addition to his five British titles, Lewis is the current British keirin champion after successfully defending his title on 26/01/2018. He was successful in winning various international accolades, culminating in five world cup medals and multiple European and world championship honours. Oliva has also represented Wales at the Commonwealth Games at Delhi 2010, Glasgow, 2014 and Gold Coast 2018. He took the silver medal in the keirin in the 2018 Games, after progressing from the first round via the repechages. His most recent competition (World Championship) representing Great Britain was the 2017 Worlds, where he competed in the keirin, his favourite event whilst balancing a vigorous training regime alongside his demanding studies at Cardiff Medical School.