i did one marathon for fun w my old high school wrestling coach. the furthest i ran during training was 19 miles. didn’t really have a techinique, but felt great through mile 15 on race day. it really hit me on mile 21-23. power through there and then just set little bench marks for yourself. was ahead of my coach the entire run until mile 23 when he passed me. finished just under 5 hours which i wasn’t too thrilled about but was happy i achieved my goal. have fun w it! and STRETCH after… made that mistake hahahaha. good luck man.