I remember doing my medical in 99 in Scotland somewhere and it consisted of the normal medical examinations, urine tests for drugs and alcohol, eye tests etc and for the fitness side it was a 1.5 mile run in under 12 minutes ( drops to 10 minutes when you do your training in the Infantry ) there were strength tests with Ammo tins to see if you could lift a set amount of weight, they counted how many pull ups and sit ups you could do. I would imagine you will have to do some sort of written exam if you are going into a trade in the Navy as the lads who wanted to be in the Engineers had to sit one. Can't remember if there was anything else it was a long time ago lol.