A consultant at Morriston Hospital is prescribing lung cancer patients with gym sessions ahead of surgery.
75 per cent of patients became suitable for surgery after a six-month pilot scheme, according to consultant surgeon Ira Goldsmith.
Patients received two 70-minute sessions a week over a three-week period.
Mr Goldsmith said patients were initially skeptical about the prescription, with some believing there was nothing they could do about getting old.
"Yes they have frailty because they are old, but you can give them primary physiotherapy and rehab, and improve them.
"We could show their survival rates were the same as those who don't have frailty."
The pilot programme involved a physiotherapist assessing the patient before they were taught the exercises.
"There are 12 stations in all and they go around the whole circuit alternating lower body and upper body exercises," Mr Goldsmith said.
He added: "We found that by improving their breathlessness they are safely able to undergo surgery.
"Most importantly, it was making inoperable patients operable."
Mr Goldsmith hopes the initiative will be rolled out across Wales.