Religion has had an ambivalent relationship with sports and leisure in Wales over the centuries.  In pre-industrial Wales, saints’ days or ‘gwylmabsantau’ as they were known in Welsh were seen as occasions for games and activities and the church buildings and adjacent lands were used as part of them.  In 1804,  the author Benjamin Heath Malkin noted that 'Young men play at fives and tennis against the wall of the church' in several parts of Wales.

With their emphasis on self-discipline, thrift and good use of time, eighteenth-century Nonconformists frowned any sports that could be seen as conducive to unruly behaviour.  Their reaction was to form an alternative culture of leisure that revolved around the chapel and stressed the importance of activities that were edifying for the individual and in no way conducive to violence.  Chapel activities included the Gymanfa and the Sunday School.  The Sunday School, in particular, organised social events for generations of children in Wales in the 19th and 20th centuries.

In the mid-19th century, public schools began to use team sports to instill Christian values in their pupils.  There emerged a form of muscular Christianity that championed athleticism as a way of developing strength of character and the virtues associated with good sportsmanship.

By the turn of the twentieth century, Nonconformists began to relax their general attitude towards popular sports although opposition to playing games on Sundays remained strong.  It was in 1974 that the Welsh Rugby Union sanctioned club matches on Sundays.

Sources
Martin Johnes, A History of Sport in Wales (Cardiff, 2005)
Gareth Williams, 1905 and All That (Llandysul, 1991)
The Welsh Academy Encyclopaedia of Wales, (Cardiff,2008)