[1] Univ Cape Town, Fac Hlth Sci, Dept Human Biol, Div Physiol Sci, Cape Town, Western Cape, South Africa
[2] Univ Cape Town, Fac Hlth Sci, Hlth Phys Act Lifestyle & Sport Res Ctr HPALS, Dept Human Biol, Cape Town, Western Cape, South Africa
[3] Leeds Beckett Univ, Carnegie Appl Rugby Res CARR Ctr, Carnegie Sch Sport, Leeds, W Yorkshire, England
[4] Leeds Beckett Univ, Ctr Sport Coaching, Carnegie Sch Sport, Leeds, W Yorkshire, England
[5] Leeds Rhinos Rugby League Club, Leeds, W Yorkshire, England
[6] Trinity Coll Dublin, Sch Med, Discipline Physiotherapy, Dublin, Leinster, Ireland
[7] Rugby Football League, England Performance Unit, Manchester, Greater Manches, England
[8] Univ New England, Sch Sci & Technol, Armidale, NSW, Australia
[9] Sports Sci Inst South Africa, Fac Hlth Sci, Dept Human Biol, Private Bag X5, ZA-7725 Cape Town, Western Cape, South Africa