OK - I can actually give some insight into this. I live in HK and often go hiking before a flight. Typically I would leave my hand luggage in the lockers at the Tung Chung shopping centre (they are in the basement). Then I would do a hike (you could easily run, there is a good route from Tung Chung to Mui Wo along the Olympic Trail or to Tai O along the coast, take the bus back in both instances). Then I come back and shower in the Cathay lounge and catch my flight.

HOWEVER.

You may wish to bear in mind that the Great White Elephant to Zhuhai opened a few weeks ago. (Aka the bridge to Macau). So now, particularly on weekends, instead of a nice peaceful shopping centre in Tung Chung, there are hordes of mainlanders. Meaning I suspect all the lockers will be full. So you'd better leave your luggage in the airport. I tried to do that last time (I had 4 hours between flights) and the queue was really long for the left luggage so I took the bus to Tung Chung and left it there instead anyway.

So, if I were you, instead of trying to do something closer to the airport, I would catch the Airport Express Train to Tsing Yi or Kowloon and run (or sightsee or whatever) there. There are interesting hike/trail runs on Tsing Yi. If you go all the way to Central, actually you can walk up to Bowen Road which is a popular running area. In Kowloon there is an area of park-type land near Kowloon station which is also nice.

!0 hours is OOODLES of time. I managed a 1.5 hour hike up Lantau Peak in my 4 hours turnaround a few weeks back, including messing around finding somewhere for the luggage. Many shopping centres in HK have luggage lockers (Discovery Park in Tsuen Wan does, for example). Very cheap, always empty. You can then run along the waterfront which is not a bad area. Or up into the hills if you like trail running. Tsuen Wan is a short taxi from Tsing Yi station or take A32 bus direct to Discovery Park shopping centre (final stop).

It's not only a good idea, it's very easy. If you want to shower before you come back to the airport, just about every sports centre in HK has free showers. But you have to bring your own towel, so for the luxury experience the airport lounge is a better bet.