Swiss distance runner Viktor Roethlin will miss the London Marathon next month after lung problems forced him to take a break from training.

Roethlin said Tuesday he is also unlikely to compete in the marathon at the world championships in Berlin in August. He won marathon bronze medal at the 2007 worlds in Osaka, Japan.

Doctors ordered the 34-year-old Roethlin not to run for four weeks after he suffered a pulmonary embolism and buildup of fluid in his chest. He must take blood-thinning medication for six months.

Roethlin said he believes the problems started with a thrombosis he developed after taking a five-hour flight from Ras Al Khaimah in the United Arab Emirates.

Roethlin finished sixth at the Beijing Olympics

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