Doctor Andrew Murray is at it again. Not content with running from Scotland to Morocco, galloping up Mount Kilimanjaro or jogging to the North Pole, he has this week announced that he is going to run the 10 highest Scottish mountains in one day.

This is why:

‘We are doing this because we had a free Saturday and fancied a challenge.’

Reasons do not get better than that.

‘We’ is Andrew and his running mate, Donnie Campbell. Campbell has form: he once ran 184 miles from Glasgow to Portree without stopping to sleep.

I fancy a challenge too. And I’ve got a free day. Next week. Tuesday, July 15.

I am yet to find a running mate, however. Donnie Campbells are hard to come by.

You enjoy your iconic, windswept, idyllic mountains, Andrew and Donnie. I have a different plan, a making-the-most-of-what-I’ve-got plan:

To run the summits of the 12 Inner London boroughs in one day.

That is – in order and in a clockwise arc – the highest natural points in Hammersmith and Fulham, Kensington and Chelsea, Westminster, Camden, Islington, Hackney, Tower Hamlets, Greenwich, Southwark, Lewisham, Lambeth and Wandsworth.

Together, these summits add up to 957m – a slouching Scafell Pike. Think of the whole thing as a satire of the Bob Graham round. Utterly pointless. But then, is not that the point?

I am not sure how long the run is – it could be 30 miles, but 40 may be nearer the mark – and I am not sure how long it will take. It is perhaps best not to know. I’ll probably have to drop-off and pick-up my daughter from nursery, meaning around eight hours will have to suffice. Any longer and a 16-month-old girl is going hungry.

Down here in London, we are stuck with the capital’s vertically-challenged undulations while our highest points have been built on, buried under concrete or adorned with telecommunications paraphernalia. The highest point within the M25 circle, faraway from the urban chaos in the North Downs, is 270-metre Botley Hill. They stuck a telecommunications mast there, naturally.

I looked down on London from The Shard very recently. I can confirm that London – from some 300 metres up – is appallingly flat. Even the Crystal Palace ridge, away to the south and positively Ben Nevisian close to, is smothered by perspective.

Nonetheless, my response to Andrew Murray is this.

• He is calling his challenge the ‘Big 10’; I’ll call mine the Little Dozen.

• He is doing his 10 in one day; I will do my dozen in one day.

• His 10 add up to more than 10,000m; the Little Dozen do not exceed 1,000m.

• He will start on 1245m Ben Lawers; I will begin on College Park, the 45m summit of Hammersmith and Fulham, a concrete summit standing precisely 1200m lower than Ben Lawers and close to a Travis Perkins depot.

• He will finish in the Cairngorms on 1291m Cairn Toul; I will end my journey on Putney Heath, the 60m roof of Wandsworth.

• His Big 10 has never been done; I can safety assume nor has the Little Dozen.

• His obstacles will include boulder fields, perilous cliffs and knife-edge aretes; I must take account of rambling, iPad-touting tourists, low-flying pigeons and cracks in the pavement.

• He is running to showcase the benefits of regular exercise; that will do for me too.

• While Andrew and Donnie will have to do battle with the A82 and A9, I will run continuously through Europe’s greatest capital, bowling by Lord’s, crossing Hampstead Heath, hot-footing along the Regent’s Canal, through the Isle of Dogs, under the Thames, across the Greenwich Meridian, past the old Crystal Palace and wombling over Wimbledon Common.

• And, of course, I have a ‘free day’.

The summits

1. Hammersmith & Fulham – College Park (45m)

2. Kensington & Chelsea – Harrow Road (45m)

3. City of Westminster – St John’s Wood Park (52m)

4. Camden – Hampstead Heath (134m)

5. Islington – Highgate Hill (100m)

6. Hackney – Seven Sisters Road (39m)

7. Tower Hamlets – Bethnal Green (16m)

8. Greenwich – Shooters Hill (132m)

9. Lewisham – Sydenham Hill (112m)

10. Southwark – Sydenham Hill (112m)

11. Lambeth – Westow Hill (110m)

12. Wandsworth – Putney Heath (60m)

@MuirJonny