Three kettlebells ate my hamstrings

I have been trying to get fit (at least for me), so I am slowly starting to train with weights. I was doing so well, before the tress of preparation for the two conferences I went to this year. If you come into my flat, you will see three kettlebells. These are a great workout but I never do them regularly enough. In fact you will notice that there is dust on the kettlebells -- as though they rarely get used.

I did train with them yesterday, And now I remember why I don't use them too much. My hamstrings are on fire. Still no pain -- no gain.