Negative work involves high muscular tension at a low metabolic cost.
The Royal Society of London is a place of research and discussion. There are between 1300 and 1400 'Fellows' with 44 being appointed each year. Member Tim Berners-Lee brought us the World Wide Web, Francis Bacon gave us the Scientific Method. Isaac Newton, Michael Faraday, Charles Darwin, Ernest Rutherford are just a few of the names of this great scientific community that has helped shape humanity. There are currently 25 Nobel prize winners among the Fellows.
In 1952 Nobel Laureate A.V. Hill at the Royal Society in London, in front of his Fellows arranged two bicycles in opposition to one another. One subject pedalled forward the other resisted this movement by back-pedaling. The speed was the same for both and the forces exerted were the same. All the work done by one subject was absorbed by the other.
The experiment was well received by the Royal Society as the young lady remained fresh doing the negative work and quickly fatigued and exhausted the young man pedaling forward doing the positive work. She developed her muscular tension while her muscles lengthened to brake the motion. The young man required 3.7 times as much oxygen trying to instigate motion rather than stop it and got whooped by the lady.
What Hill demonstrated was a muscle can develop greater tension when it tries to shorten during a stretch and the energy absorbed, that is the negative work done, is absorbed with little metabolic cost.
When you play offense line in football there tends to be more absorbtion of energy at a lower cost. It is quite different than the metabolic cost of playing defense - hence the offense lineman need not be as sleek.
This past week Russ Grimm former star player of the Washington Redskins was inducted into the Pro Football Hall of Fame. He was a part of one of the greatest offensive lines in the history of football, the fabled group called - 'The Hogs'.
The story goes that in 1982 during training camp their offensive line coach, Joe Bugel was working with his somewhat 'chunky' bunch, upon sending them to hit the blocking sleds, he said, "Okay, you Hogs, let's get running down there." Other players on the team were delighted in hearing this seemingly derogatory remark and so... Hogs it was.
Of course, Joe Bugel was referring to his group in an endearing way. He understood being a Hog was okay as the metabolic cost of playing offense line was different than that of the men his lineman would go against. The way the Redskins were playing ball bigger was better. Bugal was rather comfortable with not only his Hogs size but their three Super Bowls as well......... and so were the fans.