Freedom of information (FOI) figures obtained by the Scottish Conservatives have shown more than a quarter of a million hours were carried out in the first five months of this year.
A total of 3,342,486 hours of paid overtime have been undertaken, with Scottish Ambulance Service staff working an average of 612,000 additional hours a year.
The figures, which equate to almost 1,700 overtime hours a day, come as ambulance staff from the GMB Scotland union have announced a 26-hour strike, starting at 6am on November 28.
And Unite members have announced they will no longer work overtime amid the flat rate offer of £2,205 per person, backdated to April.
Health secretary Humza Yousaf has previously said the industrial action was disappointing, but insisted the Scottish Government had no more money to increase the offer.
Ms Sturgeon yesterday backed her health secretary, saying Mr Yousaf had her “absolute confidence” despite calls for him to be sacked.
The First Minister urged opposition parties to stop their “political game playing”. “I have absolute confidence in Humza Yousaf,” she said.
“Anybody who thinks the challenges – the very real challenges – our National Health Service is facing now is down to who the health secretary is, probably doesn’t understand the nature of those challenges.”
The FOI figures show the total yearly overtime costs have increased by 50 per cent since 2017 – from around £11.8 million to £17.5m last year. And the total overtime costs since 2017 has surpassed £75m.
Dr Sandesh Gulhane, health spokesman for the Scottish Tories, said the figures were “deeply concerning”.
He said: “Not only do they underline the huge impact overtime bans will have on our vital emergency services, but they also show how reliant we have become on the goodwill of exhausted frontline staff.
“Ambulance staff are used to unimaginable pressure, but years of SNP failures on workforce planning have left them understaffed, overworked, and ultimately brought them to breaking point.
“It’s no wonder paramedics and ambulance workers feel they have no choice but to take industrial action.
“The SNP are already presiding over a crisis in our A&E departments – strikes and overtime bans in our ambulance service could be utterly devastating this winter.
“It’s clear that frontline NHS staff – like the rest of the country – have no faith in Humza Yousaf to give them the vital support and fair working conditions they deserve.
“Humza Yousaf has completely lost the trust of our heroic NHS workers.”
A Scottish Government spokesperson said: “Our recent funding boost to the Scottish Ambulance Service has seen record recruitment of 540 additional ambulance staff last year with further recruitment for this year already under way.
“The safety of patients is our top priority and while we will do everything possible to avoid strike action, we are working with boards to put detailed contingency plans in place.”