Bones Should Be Jarred BUT NOT Joints

Bones Should Be Jarred BUT NOT Joints

This article I wrote after reading an article which appeared in the March 9, 2014 issue of The New York Times Magazine.

I read a piece recently in the New York Times Magazine which caught my eye as it is relevant to how we use our bodies.
Bones should be jarred, they get stronger. Many experiments in the past have shown that by presenting excessive forces to bones in the form of abrupt stress, shock, this leads to them adding mass or reduces mass losses, as the subject ages. The debatable issue is the amount of stress forces required to stimulate bone and how to create these forces in a daily routine.
Recent studies at the University of Bristol collected data from male and female adolescents. At this time of the life cycle bone mass accumulates rapidly. The bone density of their hips, were measured as their daily activities were monitored by means of an activity monitor. 
After a week the scientists downloaded the data gathered by these activity monitors and measured the G-Forces received by each of the teenagers. This would allow an accurate measure of impact. The teenagers who underwent the greatest impacts of >4.2G's, although not the most frequent impact, showed the strongest and highest density hip bone mass. The researchers then had to show what sort of impacts would create this type of increase in bone strength and density. Running a 10 minute mile or jumping onto a box at least 375mm high would create the relevant forces. These findings suggest that people would have to run relatively fast or undergo a lot of jumping to recreate the force required to build bone.
As we age we become more lethargic and this in turn was addressed by the researchers. In an attempt to discover how jarring could help older people and to monitor the effects of this, the researchers took 20 women older than 60 years, equipped them with activity monitors, then put them through an intense aerobics class. They also put them to test with a brisk walk and a session of stepping onto a 300mm box. None got even close to 4G's, in fact 2.1G's was the maximum force received. Suggesting that the older we are the more careful we become.
With these implications Dr Jon Tobias, professor of rheumatology at Bristol University, leading the research, suggested that "while impacts of less than 4G could help adults maintain bone mass it is unclear at this stage as to how much force below 4g would be needed. His results also led him to believe that young people and healthy adults could show great gains in bone density by running. 

Sprinting, jumping off a 375mm box and jumping back onto it, hopping in place, were all shown to increase bone density and strength. There have been other studies done on women aged 25-50 years, which have shown significant increases in bone density after hopping 10 times twice daily over a four month period, with a 30 second interval between hops. This experiment was taken one stage further to show what happened after increasing the hopping to 20 times daily all at one time with 30 second intervals. Not surprisingly the increases in bone density were greater from the later of the two experiments.
The unfortunate catch in all of this is proposed to older individuals who may not have been doing any high impact exercise. Their circumstance may not allow them to impact their bodies to the extent required to make gains in bone density. This is bound to have a detrimental effect on their overall bone health. Research by Dr Tobias and his colleagues is ongoing and they hope to better understand the levels of impact required to benefit all ages and abilities in the future.
The important thing to remember here is your level of understanding before undertaking any form of "high impact" exercise. This is especially important if you have any joint issues where a properly qualified sports physician would be best consulted. For me, just like Dr Tobias "I plan to keep running till my joints wear out".


Colin McPhail says this to Dr Tobias "If you look after your joints by using your body as a spring, in the words of Dr Jim Stoxen, you will make them last and not wear out". So these kind of reports are all good and when we start to put things into a flowing prosepctive they start to make sound advice which will allow us to enjoy life as we grow older. Lets face it we are all destined to live longer if we avoid obesity, now one of the greatest killers on the planet. Get out there and jarr your bones but use your springs to prevent the shock from reaching the joints, avoid the foods that damage and use some of the natural foods that are available in abundance, live happy, live long, live injury free, balance your life.
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