This loss of stamina is the worst part of aging. I used to be the classic Durocell Bunny, keeping going when all others had keeled over with exhaustion. Now I plan activities carefully.
This morning I put a coat of paint on one wall in the living room, had a sit down, coffee, read the papers, decided that I now had the energy to help DH cut some wood. Looked at pile that we would previously got on with and cut in half an hour. Divided it into three piles, saying we will do this today, that tomorrow et . Good sit down and lunch, then did 30 minutes gardening. Later on may spend 30 carefully counted minutes tidying the garage.
Once, by now the wood would all be put and stacked, garage tidied and lots of gardening done - before lunch.
Ah well I am just grateful that I can still do all these things, if not as quickly as before and without stopping.