The deadlift is the best gym exercise for any over body development and strength gain bar none. An engine can weigh hundreds of pounds. The tires take doors weight and force, and have to be inflated spets the manufacturer's terms. http://git.the-archive.xyz/derickoldaker4/lifting-chain2014/wiki/2-Great-Strength-Training-Exercises-For-Marathon-Barefoot-Runners%21