You do not need to look far to understand how the new scheme might work. Health insurance companies like Vitality have been running exercise-based reward schemes (where step counts can be used to knock the price down on gym memberships, say) for some time and there are already health currencies like Sweatcoin, which anyone with a mobile phone can sign up to. “We want a healthier you on a healthier planet,” says the Sweatcoin website, which already has 50 million users across 51 countries. “We achieve this by converting your steps into a currency to spend on cool products and services.”

Here I should mention I once set up a company, StepJockey, which incentivised and “gamified” corporate stair use. It was seed funded by the DHSC and for many organisations which installed it, it worked a treat. Bright signs showing calorie counts nudged you into hidden stairwells from plush corporate lobbies. You could touch an app against signs at the start and finish of your climb to record your stair count. League tables were displayed on company screens and prizes would be awarded to the movers and shakers each month. Every few months clients would launch competitions such as Climb Everest, where staff would divide into teams and compete to scale the equivalent height of a Himalayan peak on the office stairs. In some of these competitions, people from offices all around the world got involved.

Sweatcoin’s system is better still. It utilises the sophisticated movement APIs offered by Apple and Google as part of their mobile phone operating systems. They automatically record your steps, speed, mode of exercise, estimated calorie burn and so on, feeding it into Sweatcoin – which promptly converts that into Sweatcoins. Your accumulated digital currency can then be traded for vouchers and products offered by 101 different partners. The Vitality health insurance scheme works in much the same way.

Where more certainly is required to ensure that the system is not being gamed – that you have not strapped your phone to your washing machine, for example – you can utilise the phone’s GPS positioning system to check the user’s movement or ask them to scan strategically placed QR codes, if needed. Physical signs you can interact with could work too and have the added benefit of being visually salient, nudging people into action.

If it’s all so easy, why are health currency apps not more widely used? A raft of bear traps – ones the Government will fall straight into over the next few months, no doubt.

First, every new scheme worries terribly about security, rather than simply taking the data from Apple and Google and getting on with it. They spend months and many hundreds of thousands pounds designing their own bespoke and inordinately more complicated system that no ordinary consumer will ever understand or be tempted to use. This is despite everyone knowing the golden rule of all fitness apps: they must be simple and completely hassle-free.

Second, and more fundamentally difficult, no health currency has yet found a way to create real value. The likes of Sweatcoin have value enough to secure some corporate vouchers and products but it’s all a bit random, dependent on what Corporation X wants to get rid of this month.

This of course is where the Government could transform things: Corporate X has no real interest in your health, it just wants your custom. The Government, on the other hand, has a very clear and direct interest in our wellbeing. According to the Department of Health, physical inactivity is responsible for one in six UK deaths (equal to smoking) and is estimated to cost the UK £7.4 billion annually (including £0.9 billion to the NHS alone).

In short, the Government has every possible incentive to underwrite a currency for movement, attaching a real and fixed financial value to every step you take.

“Imagine if every Sweatcoin you earned could be offset against your annual tax bill or used to pay for healthy foods,” says the app’s founder, Anton Derlyatka.

“Everyone with a smartphone could be incentivised to move more from this time tomorrow morning.”