I am a manual handling instructor and was told I would have to go back every 3yrs for refresher training. Trevor

Think three years is the rule of thumb and that is all it is. You would have to be able to demonstrate a level of competence. For the guy who is not training very often - if at all why bother spending the money? We have the same issue with our first aiders and maybe I am one of the only ones who is pleased to see that the HSE recommend a yearly refresher half day. We have 10 first aiders but of those only 5 - predominantly from the shop floor - are the ones doing any treating - with 5 who rarely so much as issue a plaster - for them the annual refresher will be a good thing.

Oh, and as to the specific scenariors, anybody who hasn't delivered training for a 'number of years' really has to be re-evaluated at the very least before being allowed to train; they will probably need to be re-trained. You seem to be hinting that you think that people who train more frequently are less likely to need immediate re-training, and generally I would agree with you. The fly in the ointment is that they could have been delivering naff training several times a year, so you need to get both people refreshed, but I would say the priority has to be the dormant trainer. Certainly at my previous place of work we would deliver manual handling training more frequently to people who did less handling, on the basis that since they were given more opportunity to practise their skills would be less likely to deteriorate - that's an analogy, as you are talking about train the trainers' training, but the principle is the same, John