Because some people struggled with load carries when I was in Training, we were made to carry weight everywhere we went. It did help and after a while you don't feel it as you become accustomed to carrying it. If you want to be able to cover large distances with weight, you need to TAB or yomp. This is basically walking at a ridiculously accelerated pace such as in Benny Hill sketches, with a bit of running now and then to shake out the leg muscles. It isn't fun though, I have no idea why you would want to do it!
The Combat Fitness Test, or CFT as the Army has to abbreviate everything, is 8 miles in two hours with a load and rifle over varying terrain, normally woodland and tarmac. The load is variable depending on sex and which part of the Armed Forces you serve in, very heavy for Teeth Arms, very light if you are a woman in the RLC! Regardless, you don't get to the end and start running about because you enjoyed it, most people are totally hooped!
I remember doing my CFT before leaving Training Reg at Gibraltar Barracks. I had missed my Troops' CFT as I went to a funeral, so I ended up doing it with the Instructor Course, people who had been selected to be posted to various Training Units as Instructors. They were all older blokes yapping about Germany and how they did their last CFT in 1 hour ten minutes and faster! This was starting to concern me as I was never very good with weight at speed due to my slight build. After two hours, I was first to cross the line with a PTI and had to wait for ten minutes for the rest to turn up with the other PTIs! They'd been bragging and it had backfired on them as it was proven to be just that, talk!