The Committee of General Practice Educators (COGPED) recommends that GP registrars complete 72 hours, or 12 sessions, of out-of-hours work in their final year of GP training.
COGPED chairman Dr Barry Lewis said it was essential for registrars to spend enough time in out-of-hours to be able to demonstrate their competency and achieve their certificate of completion of training.
Wessex LMC chief executive Dr Nigel Watson said in his area, GP registrars were struggling to get out-of-hours sessions and finding it increasingly difficult to complete the 72 hours.
'Out-of-hours is becoming increasingly commercial and it is all measured on productivity. If you've got someone sitting in with you, it's going to take more time,' he said.
Dr Watson added that a lack of GP trainers taking on out-of-hours shifts had also contributed to the problem.
Dr Lewis said demands on out-of-hours providers had increased after the rollout of a GMC quality management framework in 2010.
GPC trainees committee chairman Dr Krishna Kasaraneni said the trend was worrying. 'Some providers see training as a drain on resources. There has to be a balance,' he said. 'Trainees are suffering because in some places they almost have to beg for out-of -hours sessions.'