The top Welsh club teams will compete at the ERRA National Road Relay Championships in Sutton Park on Saturday.
Men will compete over 12 stages with competition in the women's race held over six stages.
Cardiff AAC winning the 6 Stage Road Relay Championships
Welsh teams dominated the ERRA Autumn Relay Championships last October with Cardiff AAC and Swansea Harriers taking Gold and Silver medals respectively. Cardiff AAC won silver medals at this event in 2013.
Swansea Harriers are likely to be the stronger team this time however. In form Dewi Griffiths will lead them as they aim to get amongst the medals.
Aberdare Valley AAC are also fielding a team in the event which is the highlight of the endurance running calendar for clubs in the UK.
Swansea Harriers women's team took Bronze medals in April 2015 and on paper appear to be strong enough to mount a real challenge on Saturday.
Cardiff AAC were the Bronze medalists in October and are also fielding a team.