Michael Phelps may be known for winning a record 22 Olympic medals. What's less known is that whenever he gets ready to race, he walks to the starting block, takes off his headphones that have been blasting Michael Jackson, and swings his arms three times.
Before tennis player Serena Williams won gold in women's singles, she took her shower sandals to the court, tied her shoelaces in a specific way and bounced the ball five times, as she has in every competition for more than 15 years. She also wore the same pair of socks she had been wearing throughout the Olympics, like she does at every tournament.
Athletes are often a superstitious lot. Despite quantum leaps in science and massive training budgets, sportsmen and women of all skill levels swear by superstitions and elaborate rituals to enhance their performance.
"They feel more secure when doing these things," said Dr. Jens Kleinert, a Sports Psychology professor at the German Sports University Cologne. "It can be a way for them to concentrate."
As an example, Kleinert cited Jamaican sprinter Usain Bolt, who is known for pointing to the sky dramatically before each race. One minute, Kleinert said, Bolt could be hamming it up with reporters or spectators. The next minute, he's in "concentration mode."
Superstitions may indeed have a powerful effect. US gymnast Danell Leyva likes to pull a grayish-blue towel with stars on it over his head between events. Any doubts about its power were erased earlier this year, when Leyva forgot to pack the towel and had one of his worst meets in a long time, falling on the parallel bars and finishing a distant fourth. The towel has become so famous it even has its own Twitter account, @leyvastowel.
But does the credit lie with superstitions themselves, or something else?
"The rituals athletes go through before competition are a form of mental preparation aimed at helping the athletes focus and concentrate on the task at hand," said Dr. Bradley J. Cardinal, a professor and co-director of the Sport and Exercise Psychology program at Oregon State University in the US. "They help the athlete minimize distractions and stay task-focused. They can help athletes reduce anxiety and enhance their confidence."
Psychologists say that people can become superstitious when faced with unknown or otherwise stressful situations. The stress of facing the uncertainty of a match, some experts believe, is what drives many athletes to engage in what can otherwise be seen as bizarre methods of preparation.
"World-class athletes prepare for different scenarios and the 'routine' helps them keep the situation 'normal,' no matter what is happening around them," said Cardinal. "The routines help the athletes achieve high level focus, concentration, and not being distracted by the irrelevancy of what is going on around them. Having experienced everything and anything imaginable before the event ever happens helps the athlete know that they are ready, thereby reinforcing or perhaps even boosting their confidence."
A 2010 University of Cologne study discovered in two separate experiments that superstition has a powerful psychological effect on performance. In one experiment, participants were given either a "lucky" golf ball or an "ordinary" one before being asked to make a putt. Those who were told their ball was "lucky" were more successful than those who did not believe their ball was lucky.
In another experiment, participants were asked to bring a lucky charm with them to take a memory test. Half of the participants had their charms confiscated before the test. Those who kept their lucky charm performed better. The findings were reported in the journal "Psychological Science."
Almost three dozen studies on superstition and sports performance have found that superstitions can increase an athlete's self-confidence, which in turn helps them perform better.
Deeply superstitious, Australian swimmer Stephanie Rice will do eight arm swings, splash her body with water four times and press her goggles to her face four times before a race. She did not win a medal in London.
Some superstitions are just downright gross, regardless of the confidence boost. For example, whenever former Argentinean football goalkeeper Sergio Goycochea was about to face a penalty kick, he would pee on the pitch.
Other athletes are superstitious - about superstitions.
"I'm superstitious about having any superstitions," Australian diver Matthew Mitcham was quoted as saying on his official Olympic profile. "I do my best to quash any of that … creeping up on me."
Sports psychologists, however, warn that athletes can take some superstitions too far, actually having a negative effect on their performance.
The main danger, they said, is that athletes can become too "fixated" on a ritual, such as wearing the same pair of shorts underneath their uniform (as Michael Jordan did during his NBA career).
"On one side it's easy for athletes to focus with rituals," said the German Sport University's Kleinert. "But he or she can become dependent on these things."
Good coaching, though, can discourage such fixation.
"Great coaches will discourage associating outcomes with something like a pair of socks because, eventually, the socks will wear out and new socks will need to be worn," explained Oregon State's Cardinal. "If the athlete is worried about wearing the wrong socks, that is an irrelevant distraction and it can harm performance if allowed to continue. Great coaches and athletes will know and understand this."