This week I’ve been in Kazakhstan running a workshop for a school that will be applying to implement the IB diploma program. Hotel life can get a bit boring so I’ve been driven to use the gym and have been working my way around the apparatus. First day was the treadmill. This was a sophisticated piece of equipment with many settings and measurements. I was particularly intrigued with the mix of units used.

Speed: minutes/km
Power: Watts
Energy: Calories

 The photo shows the read out, I’m sorry it’s a bit blurred but that’s because I was running at the time, almost got thrown off the back of the machine whilst taking it. I still can’t work out what I‘m doing work against, the track is moved by a motor so I don’t seem to be giving the track any energy. Maybe it’s just the energy required to move my legs back and forwards. Each step I have to accelerate my legs so this would require work but the amount of WD would depend on the mass of my legs (very small in my case) rather than my total mass. If this is the case it also answers the question about why it’s more difficult to run on an inclined track. This has always baffled me since you’re not actually going uphill so where is the energy going, but believe me it is more difficult. So maybe the answer is that on an inclined track you have to lift each leg upwards each step even though your centre of mass isn’t moving. I can feel an interactive physics simulation coming on but in the mean time I think I’ll try the Nordic skiing machine.