The hand saw is one of oldest tools we still use. You can get quite a workout cutting wood with one. There must be a better way though. Well, John Zimmerman, a software developer, has come up with the Recoil Saw which has spring-loaded impact bars attached to the blade.
What that means is that at the end of each stroke, the spring will compress as the bar hits the material being sawed, followed by a release of energy flowing back into the following return stroke. It enables you to ‘bounce’ through wood, so you won’t get as tired.