To shave, or not to shave

“Since this is a bumper year for sport, I want you lazy lot to do something on the science and myths in sports” came the terrifying words from the Editor. Not the Science Lite team’s favourite topic – unless it involves a few alcoholic beverages down the pub while watching the latest match, but actually some of the things we found out were quite interesting.

Did you know that swimmers shave their body hair because they think it makes them faster, but cyclists do it to make wounds easier to clean? We’ve always thought that there was something a bit strange about grown men shaving their legs but it turns out there is some benefit in the practice.

Swimmers first shaved off their body hair at the 1956 Australian Olympics, and in 1989 a study published in Medicine and Science in Sport and Exercise showed that it does indeed reduce drag. It compared nine swimmers who shaved their arms, legs and exposed trunk against nine swimmers who didn’t – removing hair significantly reduced rate of velocity decay during glide under maximal underwater leg push-off, suggesting shaving reduces active drag and deceased physiological cost of swimming.

Shaving also gives swimmers a psychological boost – skin is more sensitive because the top layer of dead skin has also been removed, making the swimmer feel invigorated and feel more aerodynamic.

We always thought cyclists shave their legs because they think it makes them go faster – and although a 1987 study showed an aerodynamic improvement – many cyclists say this isn’t their reason for shaving their legs. When questioned by Bicycling magazine cyclists said they shaved their legs because it makes injuries less severe and easier to deal with. Hair acts like Velcro against an uneven road surface, pulling patches of skin from the leg – not a problem if there’s no hair. It’s also easier to clean wounds – or apply sunscreen and get a massage – without all the hair in the way. We’re guessing that also means it’s less painful when pulling off the plaster and dressings too then!

Another interesting fact we came across was about the size of tennis balls. We admit we find Wimbledon a little boring – not because the ball just goes backwards and forwards in a rally – in fact it’s rather the opposite: we’re fed up of the ‘aces game’.

Scientists hoped to resurrect the rally in 2001 with balls that were 6% bigger and slower, meaning they’d take longer to reach the baseline and give opponents more time to react, but even with this tactic employed, the game still suffers from an overwhelming number of aces. Remember the 2010 first round match between John Isher and Nicholas Mahut? Not only does it go down in history as one of the longest matches – in terms of time and number of games – Isher hit a record breaking 113 aces, with Mahut close behind with 103. Perhaps we need to go back to the age of wooden rackets to slow the game down again?

And of course, there’s the one sport we do love – football (particularly if there’s a beer involved). And with the Euro 2012 finals over, we thought we’d look at the one thing that leaves a goalkeeper quaking in their boots – the penalty shootout.

Much of the decision on which way to dive is probably down to gut instinct, but it turns out that penalty takers might give a few subtle hints as to where they’re going to place the ball.

Research by University of Greenwich sports scientists and the West Ham United Football Academy showed penalty takers subconsciously give readable clues to the direction of their kicks which could be used by goalkeepers to improve their chances of saving a penalty.

“Various angles of a striker’s body were measured when taking a penalty, and two body parts were identified giving an indication of the direction of the shot: shoulder angle and angle of the standing leg,” said Al-Amin Kassam and Dr Mark Goss-Sampson. “Variations in these two angles revealed which of three areas of the goal (left, right and centre) the ball was being struck towards.”

The researchers believe that if goalies practice recognising penalty takers visual cues, their response will become automatic and they will improve their chances of saving a penalty. Other tactics such as making themselves look as large as possible and moving sideways on the line – perhaps not necessarily in the same vein as Bruce Grobbelaar – will also help, not that Joe Hart needs any!