Hi Gill
JY sounds ideal for you. I've done about 10 JY holidays including Peru, China & India - all have been fab and very active!
Age ranges have been from 30's to late 70's but whatever your age, it doesn't matter. Women outnumber the men. Group sizest smallest 13 largest 40 (china 40, india 28 & peru 16).
Choose a trip that appeals to you and you'll have a fab time
Anna