I never used to be a big runner – still am not. I know its great for losing fat and developing cardio, but its bad for your knee’s and hips.

Anyway some years back I was in the army reserve my time on 1.5 miles was around 10:30 or 11 minutes – which isn’t fantastic.

In the years since I have done some running but more long slow distance of several kilometers. I have however done much time on the rowing machine – 3 or 4 times per week for many years.

So my cardio has been good as a consequence of this. Now I have decided to take a crack at the army again and and have taken up the training to pass their running test. I first tried the test and failed miserably at 12:47.

After weeks and months of fin swimming, running etc I now have the time down to around 9 minutes and expect to soon have it below that.

But you know what – stick me on the rowing machine and I have not improved at all.

So whats going on ? Has the improvement in running time corresponded with improved VO2 max and cardiac output or is it just a result of better leg endurance.

Well I can tell you that after some of my training sessions in the evening when resting my pulse rate has been remarkably lower that it was formerly so that is clear evidence of improved cardiovascular output.

But most of my cardio training still is not running – its fin swimming.

I just do the runs to test myself – Its the fin swimming that is doing the bulk of the conditioning.

Fin swimming is great because it taxes and conditions the lower legs, thighs, hamstrings and is great for heart and lungs. Plus its zero impact.