China Daily (Hong Kong)

Don’t overdo it

Too much exercise might be harmful, studies show

- By ROBBIE HODGES

Studies released recently show that, despite good intentions, those who regularly exercise for two hours or more could be doing more harm to their bodies than good.

The research, which comes from Australian sports journal Alimentary Pharmacolo­gy and Therapeuti­cs, shows that intense physiologi­cal stress on the body can trigger Leaky Gut Syndrome — a condition in which the gut lining weakens, resulting in the passage of germs and toxins into the bloodstrea­m.

It’s believed that the resultant leakage of toxic waste is a primary cause of Multiple Sclerosis (MS) and Chronic Fatigue, and has a role to play in many other illnesses. With no immediate cure — though a gluten-free diet wouldn’t go amiss — those putting in the hours at the gym might be better off putting aside some time on the sofa.

But it’s not just your gut that could suffer from hard graft. There are a whole range of health risks associated with excessive exercise that the health and fitness industry would rather you didn’t know.

Whilst the gym claims to hold the key to a happier, healthier you, science seems to be saying that there really can be too much of a good thing.

A long but gentle session on the

Abnormal heart rhythms:

treadmill can’t hurt, right? Wrong. Those who regularly engage in endurance sports are at risk of causing permanent structural changes to heart muscles which scientists describe as “cardiotoxi­c”.

Such changes are believed to predispose athletes to arrhythmia (abnormal heart rhythms), making them more prone to sudden cardiac death. For years, a handful of cleanlivin­g sports nuts have sat smug in the knowledge that tobacco, caffeine and recreation­al drugs are the main causes of an irregular heart beat. But studies released by the European Heart Journal in 2013 suggest that — especially for those with a family history of irregular heartbeats — overdoing the fatburning workout can also contribute to poor cardio health.

The study, which measured the heart rhythms of over 52,000 crosscount­ry skiiers during a ten year period, found that the risk of arrhythmia is increased with every race completed, and was up to 30pc higher for those who competed year-on-year for a period of five years. Exercise intensity also affected results: those who finished fastest were at higher risk for arrhythmia.

A shaky immune system:

Cortisol — a hormone emitted by the adrenal gland during periods of physical stress — stimulates gluconeoge­nesis (the production of new glucose) in the liver and increases protein breakdown in the muscles.

It’s essentiall­y good. Keen to benefit from its inflammato­ry effects, profession­al athletes have been injecting their wearied muscles with the stuff for years (as have office workers who suffer from persistent RSI). But scientists recently came to the conclusion that the negative effects of cortisol can outweigh the benefits.

Whilst cortisol can decrease the swelling and reddening prompted by serious injuries, its immunosupp­ressive effects mean that those who endure high and consistent cortisol levels are at more risk of falling ill.

One way of understand­ing this is in terms of the ‘fight-or-flight’ instinct. Levels of cortisol increase dramatical­ly during moments of intense stress — but these moments tend to be very fleeting. You fight, or take flight, and then the body’s self-limiting response system returns to normal.

However, that doesn’t happen so quickly when you over train. Essentiall­y, your body doesn’t have time to recover, so it stays in (or close to) fight-or-flight mode. Your immune system pays the price.

Weakened bones:

Not only are those who over-exercise more at risk of illness but they’re doubly as likely to end up bed-bound thanks to cortisol’s interferen­ce with bone-building. When cortisol is in the bloodstrea­m, more bone tissue is broken down than is deposited. This means that exercise addicts, whose bodies remains in a chronic state of stress, put themselves at higher risk of fractures and breakage.

The resultant loss in bone density can lead to serious conditions such as osteoporos­is and arthritis, which can haunt excessive exercisers in later life.

Mental ill-health:

Pumping iron on a daily basis might be a fasttrack to the baywatch body you’ve always craved — but relentless­ly hitting the weights has proven detrimenta­l impacts on mental health.

Studies into what is known as ‘Overtraini­ng Syndrome’ show that those who over train portray the same biochemica­l markers as those with clinical depression — which is to say that the emission of serotonin and tryptophan are altered by both disorders. Behavioura­lly too, the clinically depressed and the over trained were perceived to share lowered motivation, insomnia and irritabili­ty.

Last year the Technical University of Munich found that young athletes who don’t leave enough time to recover from stress and injury are 20pc more likely to suffer from depression.

Struggling to find the motivation to lug your unwilling body to the gym? It might be time to ease off the weights.

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 ?? PROVIDED TO CHINA DAILY ?? There are a whole range of health risks associated with excessive exercise.
PROVIDED TO CHINA DAILY There are a whole range of health risks associated with excessive exercise.

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