I recently attempted to take some exercise at my local gym and failed miserably. Not through injury or lack of motivation, but simply because I have not yet completed a gym induction programme.
Prevented from using the treadmill, I was instead allowed to go for a swim (without any armbands)! The previous day I was also permitted to play squash in the same sports centre without any induction.
So what carries more risk - squash or a treadmill?
A quick literature search found one paper* that looked at hospital admissions relating to squash injuries in Victoria, Australia between 2000 and 2001. The authors found an overall injury rate of 35.5 injured players per 100,000. Over 90% of these patients were not admitted to hospital and discharged the same day.
As for running on a treadmill, I couldn't find any meaningful numbers relating to hospital admissions based on running inside or outside.
Using some common sense, running inside is likely to be safer than running outside because an individual doesn't have to worry about traffic or uneven terrain. When compared with squash, damage to the face and eyes seems unlikely. Injuries to the lower extremities might remain roughly the same as while a consistent pace over a longer duration may increase the risk of injury, the lack of sudden movements may mitigate this effect. Finally, squash carries the additional risk of colliding with an opponent. This doesn't seem likely on a treadmill.
From a public health point of view this is really depressing. I imagine that a fair few people have occasional flashes of motivation along the lines of 'Today, I'm going to give up smoking!' or 'Right. Tomorrow I am going to get fit'. If not acted upon quickly, this motivation will quickly evaporate.
Anyway, I have reluctantly booked my induction. Wish me luck!
*Rochelle Eime, Tsharni Zazryn & Caroline Finch (2003): Epidemiology of squash injuries requiring
hospital treatment, Injury Control and Safety Promotion, 10:4, 243-245