|>>|| No. 12364
There are minimum health and fitness requirements for all branches of the forces. Regardless of your role, you may be required to carry out strenuous physical tasks or operate in remote environments with minimal medical facilities. There are obviously significant variations in what might be required of you, which will be taken into account during a medical examination and physical fitness tests.
An engineer on a submarine doesn't have to do much running about, but they might have to perform physically demanding tasks on heavy machinery in a very cramped compartment. The submarine fleet has some of the strictest medical requirements, because of the need to operate covertly while on patrol. If someone falls seriously ill, arranging a medical evacuation might take days or even weeks. You don't have to be super fit to serve on a submarine, but relatively minor health problems like a food allergy or a heart murmur might disqualify you, because they could prove life-threatening in that environment.