Cancel your gym membership - new research suggests we can strengthen our
muscles just by thinking about exercising them.

Vitoth Ranganathan and his colleagues (The Cleveland Clinic Foundation,
USA) enrolled 16 participants on a 12 week mental training regime. Five
times a week for 15 minutes, half the participants imagined pushing their
little finger against a resisting force as hard as they could, the other
half imagined using their forearm. The participants were to do more than
just visualise performing the movement ('external imagery'), rather they
were to really imagine performing the pushing movement with all their might
('internal imagery'). Recordings confirmed they weren't actually moving
their muscles.

After the training period, the finger group saw their little-finger
strength increase by 40 percent compared with before, and the forearm group
found their elbow-flexor strength was up 13.5 percent. Eight control
subjects who didn't train, showed no significant changes in their strength.
Six subjects who trained their little finger with physical exercises for 12
weeks, showed strength increases of 53 percent. Recordings showed that both
mental and physical training led to increased electrical brain activity
associated with the trained movement. This suggests the mental exercises
had increased the size of the brain signal sent to the muscles, thus
increasing muscle strength when an actual movement was performed.

The work has implications for "improving motor function in patients who are
too weak to participate in conventional strengthening programmes, but are
mentally healthy and motivated to engage themselves in mental practice",
the authors said.

Ranganathan, V.K., Siemionow, V., Liu, J.Z., Sahgal, V. & Yue, G.H. (2004).
From mental power to muscle power - gaining strength by using the mind.
Neuropsychologia, 42, 944-956.

Journal weblink: http://www.sciencedirect.com/science/journal/00283932