IT'S TAKEN 10 years to discover that the founding principles of Pilates are flawed.
If there is a Holy Grail of fitness to have emerged over the past decade, then it has to be the pursuit of core stability, the strengthening, toning and honing of the muscles that wrap around our midriffs like a corset.
Celebrities such as Kate Winslet, Sharon Stone, Gwyneth Paltrow and Beyonce have swarmed to Pilates classes, in which the central message is that the deeply embedded muscles must be strong if we are to look good and have bodies that move freely.
They hold the spine in place, we are told, and prevent back pain by allowing us to move as nature intended. But among scientists there is dissent about whether the pursuit of a strong core is safe.
Professor Paul Hodges, head of human neurosciences at Queensland University, attached electrodes to two groups of subjects —one with healthy backs and another with persistent back pain — and got them to do a series of rapid arm raises.
His results showed that the brains of the healthy subjects seemed to send signals to a deeply embedded muscle called the transversus abdominis, triggering it to contract and support the spine just before the arms moved. In those with back pain, no such reaction took place, leaving the spine unsupported and vulnerable.
Hodges then showed that the same muscle could be strengthened by “sucking in” or “hollowing out”(pulling navel to spine) the stomach during exercises and that the effects seemed to provide some protection against sore backs. It was neither a clear link, nor was the evidence conclusive, but the concept quickly spread beyond physiology into the gym world.
“The fitness industry took a piece of information and ran with it,” says Thomas Nesser, assistant professor of physical education at Indiana State University who has been researching Pilates-style activities. “The assumption of ‘if a little is good, then more must be better' was applied to core training and it was completely blown out of proportion.”
What is accepted among critics is that too many workouts are dedicated to strengthening the deeply embedded muscles of the core, an approach that can prove futile, particularly when it comes to preventing back pain.
Two years ago, a controversial paper suggested that the importance of core strength has been overplayed and that, even if there was truth in the notion put forward by Hodges that a strong transversus abdominis muscle eased a sore back, the likelihood is that attempts to strengthen trunk muscles in the otherwise fit would probably have little benefit and may even backfire.
There is doubt, too, that Pilates leads to a more efficient body that moves freely and is less prone to the ravages of ageing. Even in sport, the tide is turning against the view that core strength is essential for improvement. When Prof Nesser looked at the top footballers, he found that those with a strong core played no better than those without.
What about those who devote hours to Pilates and improving core strength to get lean, toned limbs? Will hours on the Reformer equipment provide the body they hanker after? Not unless you do it in addition to resistance training and endurance activities such as running or cycling.
According to the American Council on Exercise, a beginner's class did not meet the recommended levels of exertion for improving even basic cardio-respiratory fitness, burning only 174 calories.