Binge TV watching, the Olympics and your health

The 2012 Olympics in London saw my patients, like thousands of others across the UK, dust off their trainers and sign up for the gym. Four years on many of their good resolutions have gone by the wayside, but the Rio Olympics have seen another burst of interest in the benefits of getting fit - or the dire consequences of being a couch potato.

Ironically, given how much time most of us already spend slumped in front of the television after a hard day's work, the Olympics may be just another excuse for yet more binge TV watching on the sofa. A new study shows that people who spend five hours a day watching TV are more than twice as likely to suffer a potentially fatal clot on the lung (a pulmonary embolism or PE) as those who watch half as much. The study followed 85,000 Japanese people over 20 years and correlated a whole series of factors (including smoking, obesity, high blood pressure and diabetes as well as lifestyle factors) against the likelihood of having a PE.

Over 200,000 people in the USA suffer a PE every year, and 2,300 a year die from one in the UK. The clot on the lung that causes PE usually comes from a deep vein thrombosis or DVT. Part of the clot breaks off and is carried in the veins back to the heart, and on to the lungs where it lodges. DVT is rarely fatal by itself, although it can lead to long-term calf pain. But if the clot reaches the lungs, it can cause chest pain (often worse on breathing), coughing up blood, shortness of breath and sometimes collapse and death

One of the risk factors for DVT and PE is taking the female hormone oestrogen. Your risk is raised by taking the combined oral contraceptive pill, often just called the COC or 'the pill' or hormone replacement therapy (HRT). In real terms, the increased risk is very small. While some COCs carry a higher risk than others, none of them raise it as much as being pregnant, where the chance is about 60 per 100,000 pregnancies. Nonetheless, your GP will always want to ask about other factors that might increase your risk of DVT, and the warning signs to look out for, before starting the combined pill. When it does happen, it's a tragedy. Just last month, UK press reported the case of a healthy 23- year-old Shropshire woman who collapsed and died from just such a complication.

A clot is more likely to form when the deep veins in the leg are compressed, so it's a particular issue for people who have been laid up by surgery. There's also a small increased risk for those taking long-haul flights, particularly in cramped seats. So perhaps I shouldn't have been surprised to hear that prolonged TV watching has a similar effect. I still found it pretty depressing, though.

Interestingly, this week's news also carried good news on how to offset the risk of too much time sitting still. 'I don't have time to exercise' is a constant refrain from my patients, who spend their whole working lives stuck in front of a computer screen. But a sedentary lifestyle can damage much more than your waistline - it's been linked to an increased risk of heart diseasetype 2 diabetes and some cancers, and may be as damaging as smoking. Now new research suggests that even those of us with the most sedentary jobs can reverse their risk with an hour's brisk exercise a day.

If you haven't so much as broken a sweat running for the bus for years, an hour's exercise a day might seem laughably unlikely. But that's where technology can also help. Sign up to MyHealth for practical tips on how you can build up your fitness levels gradually. You can start slowly - just 10 minutes walking by getting off the bus one step earlier - and build up. Get into the Olympic spirit and do your body a favour.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.