Progress at the gym this month hasn't looked terribly good since the last time I updated it. The unprecedented target of running for two straight miles really did mess up my ankle a bit, and then after going on holiday and being somewhat ill for a while, we let our previously well-kept routine of three visits a week slide - I've only added four more entries to the graph since the start of the month.


But even when doing it less, it's surprising how your increased stamina doesn't vanish. After just one exhausting session, doing the same thing again is significantly easier, as if your body completely rebuilds your legs overnight in order to cope with what it assumes is a rapid transition from office worker to hunter-gatherer. Starting the graph's axis at the nadir of 160 makes this less obvious than it could be, but I'm now achieving almost double the (apparent) calories that I used to when I started off, and a significantly greater distance - it's beginning to become difficult to believe that going for one and a half miles felt like moving at all.

I'm sort of hovering halfway through tier 6 now, where running in five-minute bursts is the minimum and running for mile-long stretches is more common. Yesterday I was ambitious and ran a full 20 minutes again - that's what the timer said, but while actually there and watching it tick up it felt like 19 minutes and then about three more years. This time, though, I'm not suffering any post-exercise injury at all.

The workouts from here get significantly duller, being just stretches of running slightly greater distances until the five-kilometre mark, but I think that my next step will be to slowly increase my running speed and see if I can get to a point where one mile really is ten minutes - 0.8mph doesn't sound like all that much of a difference...