The 22-year-old from Penny Street, Old Portsmouth, is still fighting hard to put on the weight he lost during a marathon trek across Greenland.

With a friend he covered nearly 1,300 miles of bleak wilderness, coping with freezing temperatures totally unsupported.

And that should stand him in good stead as prepares to start as a Second Lieutenant on September 1.

The Oxford graduate said: 'I have been back nearly a month but it has been non-stop. I have been processing thousands of photos and training hard to be ready for the Marines.

'During my trek I lost three stones in weight, which affected my upper body strength severely.

'So I have been going on long runs and doing exercises to get that back.

'It seems like a different world being back in Portsmouth, but I hope Greenland will have given me good experience for the Marines.'

Mr Hibbert passed his selection tests for the Royal Marines Commandos aged just 16.

To keep fit he goes running, mountaineering, hiking, skiing and white-water kayaking.