Rocky Bleier, former running back for the Pittsburgh Steelers, used intention to help the Steelers win the Super Bowl. His technique was to saturate his mind with the details of specific plays. He carried out mental rehearsals in the morning, before the team meal and last thing before drifting off to sleep every day of the two weeks before a game.
He also found it reassuring to run through the entire catalogue of moves one final time just before play. While sitting on the bench, he again rehearsed some 30 runs and 30 passes. No matter what the field threw up to him that day, he was determined to be ready.
Any modern coach of a competitive sport routinely offers training in some form of mental rehearsal, and often it’s touted as the decisive element separating the elite sportsperson from the second-division player.
National-level soccer players, for instance, are more likely to use imagery than those who remain at the provincial or local levels. Virtually all Canadian Olympic athletes use mental imagery.
The most successful internal rehearsal involves imagining the sports event from the athlete’s perspective as though he or she is actually competing. It amounts to a mental trial run. The athlete envisages the future in minute detail as it is unfolding. Champion athletes forecast and rehearse every aspect of the situation, and the steps they should take to overcome any possible setbacks.

A thought or an action?
But how can simply thinking about a future performance actually affect the day of the event? Some clues come from intriguing brain research with electromyography (EMG). EMG offers a real-time snapshot of the brain’s instructions to the body – when and where it tells it to move – by recording every electrical impulse sent from motor neurons to specific muscles to cause a contraction.
Ordinarily, EMG offers doctors a useful tool to diagnose neuromuscular disease and to test whether muscles respond appropriately to stimulation.
But EMG has also been employed to solve an interesting scientific conundrum: can the brain differentiate between a thought and an action?
Does the thought of an action create the same pattern in neurotransmission as the action itself? This very question was tested by wiring a group of skiers to EMG equipment while they were carrying out mental rehearsals.
As the skiers mentally rehearsed the downhill runs, the electrical impulses heading to their muscles were just the same as those they used to make turns and jumps actually skiing the run. The brain sent the same instructions to the body, whether the skiers were simply thinking of a particular movement or actually carrying it out.
Thought produced the same mental instructions as action.
Research with EEGs has shown that the electrical activity produced by the brain is identical, whether we are thinking about doing something or actually doing it. In weightlifters, for instance, EEG patterns in the brain that would be activated to produce the actual motor skills are activated while the skill is simply being simulated mentally.
Just the thought is enough to produce the neural instructions to carry out the physical act.
 
Laying down train tracks
Based on this research, scientists have posted some interesting theories of how mental rehearsal works. One school of thought proposes that mental rehearsal creates the neural patterns necessary for the real thing. As though the brain was simply another muscle, these rehearsals train the brain to facilitate the moves more easily during the actual performance.
When an athlete performs, the nerves that signal to the muscles along a particular pathway are stimulated and the chemicals that have been produced remain there for a short period. Any future stimulation along the same pathways is made easier by the residual effects of the earlier connections. We get better at physical tasks because our signaling from intention to action has already been forged.
It’s not unlike a train track laid down through wild, inhospitable country. Future performances improve because your brain already knows the route and follows the track already laid down.
Because the brain does not distinguish between doing something specific and just thinking about doing it, mental rehearsal lays down the tracks just as well as physical practice does. The nerves and muscles create a pathway just as sound as one produced through repeated practice.
 
Working out virtually
Beside improving performance, mental intention can produce actual physiological changes. Guang Yue, an exercise psychologist at Cleveland Clinic Foundation in Ohio, carried out research comparing participants who went to the gym with those who carried out a virtual workout in their heads.
Those who regularly visited the gym were able to increase their muscle strength by 30 per cent. But even those who remained in their armchairs and ran through a mental rehearsal of the weight training in their minds increased muscle power by almost half as much.
Volunteers between 20 and 35 years old imagined flexing one of their biceps as hard as they could during daily training sessions carried out five times a week.
After ensuring that the participants were not doing any actual exercise, including tensing their muscles, the researchers discovered an astonishing 13.5 per cent increase in muscle size and strength after just a few weeks, an advantage that remained for three months after the mental training stopped.
In 1997, Dr David Smith at Chester College came up with similar results: participants who worked out could achieve 30 per cent increases in strength, while those who just imagined themselves doing the training achieved a 16 per cent increase.
A pure directed intention can give you the burn almost as well as any workout.