The best exercise is the one someone still does in six months, and by that measure tai chi does unusually well. It needs no equipment, no change of clothes, no gym membership, and about twenty minutes. It does not leave you sore. It can be done in a hallway. And it does not require having been sporty, which rules out the thing that stops a lot of people.
What it trains is balance, leg strength through range, and the habit of paying attention to where your weight is. The evidence is strongest for reducing falls in older adults and reasonable for knee osteoarthritis. For anyone in their sixties or beyond, falls prevention is not a small claim: it is probably the highest-value thing on offer in this clinic.
Where it fits in a wider plan: it is not cardiovascular training and it is not resistance training, so it complements walking and something with weight in it rather than replacing them. For anyone in perimenopause or beyond, resistance work matters for bone and muscle and we will say so rather than pretending tai chi covers everything.
Check with a GP or physiotherapist first if you have had a fall, have vertigo, are recovering from a fracture or joint replacement, or have heart disease that is not stable. Classes can be adapted, including seated. The clinic is in Lane Cove, five minutes from the village, and the hall is flat with parking nearby.