Exercise is difficult, lack of sunlight increases depression, and very few bikini beach parties ;)
Which is why they invented skiing! Norwegians do quite a lot of physical exercise but it has to vary over the year. Cross country skiing is a good way to get into nature and is great full body workout. But yes, the bikini beach party season seems to be so short that I've missed it every year, unless you're talking about the quick run from the sauna to the icy sea.