Burning calories
Orienteering:
A great way to burn calories, thanks to the diverse terrain across which you run - up and down hills, through woods, etc. A 10-stone person can expect to burn around 575 calories an hour.
5 stars
Mountain biking:
Though mountain-biking can often cover similarly challenging terrain, it's less energy-hungry because cycling does not require you carry your own body weight.
4 stars
Adrenaline fix
Orienteering:
Mentally challenging it may be, and more exciting than jogging in town, but still orienteering is not a white-knuckle sport - speed and vertiginous heights do not factor.
2 stars
Mountain biking:
If you like a workout to be a near-death experience, mountain biking could be for you. There'll be moments of terror when you feel out of control, followed by that buzz after surviving a perilous ride.
5 stars
Lower body
Orienteering:
As with any form of running, the leg muscles are the major players. Particularly good at strengthening the muscles below the knee, but mountain biking gives more of an all-round leg workout.
4 stars
Mountain biking:
Really strengthens and tones the bottom and legs, especially when you're cycling uphill. Research shows that mountain bikers exert more power relative to body weight than road cyclists.
5 stars
Mental agility
Orienteering:
Known as "cunning running", because you have to think on your feet - research has found that ageing orienteers, compared with non-athletes, had faster reaction speeds and better attention skills.
5 stars
Mountain biking:
Though it requires concentration and fast reactions - the less familiar or more challenging the trail, the more brain power you need - it doesn't match the quick decision-making that navigating demands.
4 stars
Safety
Orienteering:
Acute injuries such as ankle sprains are more common in orienteering. But there are fewer knee injuries caused by repetitive movements, not least because it's on natural, not man-made, terrain.
4 stars
Mountain biking:
There is a risk of surface and limb damage every time you fall off your bike, and the dangers increase as you take on more challenging trials and become more confident and cycle faster.
2 stars
