Oh, there is a downside.

One of the disadvantages for Interval/Fartlek training is you can be a victim of being a lazy bastard. For example, this morning I found a number of my sprint intervals lasting 27 or 28 seconds rather than 30. This regiment requires you to push yourself and sometimes you wake up and don’t want to push yourself to the edge of exhaustion.

I think that in the grand scheme of the training, being lazy won’t cause too much of an issue, but I don’t like the look of this trend.

So watch yourself, you may be like me, a fair weather trainer.