Over the summer a friend's barn was blown down by a tornado. He announced a particular weekend in which people were welcome to come over and help clean up the mess. I arrived at 8:05 to find 30 people already at work. By 10 there were about 60. Chainsaws were buzzing, two large wood chippers were screaming, two fires were going, and a couple of bobcats were pulling stumps and moving large piles of debris. There were about 30 trees down and those with the chainsaws were slicing them up. Ant-like streams of people took everything cut off and dragged it to the wood chippers, stacked it up, or threw it in one of the fires. Others sifted through the barn salvaging good wood and either burning what wasn't or throwing it in the biggest dumpster I've ever seen. This went on for about 8 hours. After I finished I went an mowed a friend's lawn.
The next day I was fine except for some achy feet (I usually don't wear steel-toed boots ALL day) and my hands and forearms were a little tired. I can imagine most of the people were in total, screaming agony having used all kinds of muscles they normally don't. We (only 10 of us this time) did another 8-hour day at the farm then I went and helped someone move. And Monday I felt great.
Yeah, riding the bike works pretty darned good.