Zak raced in the lightweight men's double scull with Jamie Coombes at the 2012 World Rowing U23 Championships in Trakai, finishing 8th overall.

At the 2012 GB Rowing Team Senior Trials held on 10/11 March at Eton/Dorney, Zak was 7th in the lightweight men's single scull.

Zak, who is on the GB Rowing Team's Start Programme, sponsored by Siemens, raced in the lightweight men's quad at the 2010 World Rowing U23 Championships in Brest, Belarus winning a bronze medal.

Zak started rowing in year 8 of school at the Llandaff Rowing Club.  At the time he was also a keen swimmer but could not commit to both.  In September 2007 he committed to rowing and began training in Cardiff Bay with the Welsh Squad.  In 2009 he won gold in the junior men's quad at the Home International Regatta.

He is currently studying Dentistry at Manchester University and enjoys the challenge of juggling rowing and academics.  He is supported by the Lloyds TSB Local Heroes/Sports Aid programme and Stampfli boats.