For thousands of years, various forms of massage therapy have been used to relieve tired and aching muscles. Now modern science has helped to explain why it feels so good.
The hands-on manipulation triggers biochemical sensors that send inflammation-reducing signals to muscle cells, according to a study by researchers at McMaster University in Hamilton and the Buck Institute for Research on Aging in Novato, Calif.
Furthermore, the signals boost the ability of muscles' cells to make new mitochondria – the power-production centres within cells – which can affect muscle endurance, said the study's senior author, Mark Tarnopolsky of McMaster.
For the study, 11 young men peddled vigorously on stationary bicycles for 70 minutes. Afterward, each volunteer received a 10-minute massage – but only on one leg. The other leg was rested. Muscle biopsies were collected on both legs.
A detailed analysis of the biopsies revealed evidence of the signals to reduce inflammation and increased mitochondria production in the massaged leg. "I didn't think that little bit of massage could produce that remarkable of a change," said Justin Crane, a McMaster doctoral student who led the study published in the journal Science Translational Medicine.
But the study also challenged one long-held belief about massage. Some exercise specialists have assumed that massage aids the recovery of fatigued muscle by helping to flush away lactic acid, a byproduct of exercise. That is not case, Dr. Tarnopolsky said, noting there was no difference in the lactic acid levels in the massaged and unmassaged leg.