The result? He has avoided flu for two years, and works harder with renewed energy.
Here we go back in time and remember 13 remarkable moments of 2013.
A 44 per cent decline in diamond production was announced by Russian gem producer Alrosa.
Valery Malkov from Bratsk, Irkutsk region, was wearing only a T-shirt, shorts and slippers.
Puppy cuddled her, helping to keep her alive when she got lost in the Siberian taiga for 11 days and nights.
Scientific expedition on way to retrieve remains of Ice Age giant.
Oleg Rezanov says he was in ‘trance’ and unable to breathe but walked away - shaking - in -32C Yakutsk cold.
One estimate is half a million new jobs stemming from improvements to the Baikal-Amur Mainline link amid hopes of foreign investment.
Palaeontologist says osteoporosis could have been major contributor, brought on by a lack of minerals in habitat from climate change.