drop (~8-10mm). Larger heel drop means you tend to land on your heel, then roll forward to your toes as you push off. Some like the additional help, but it can put more pressure on your toes pushing off, which activates your calf muscles more. I prefer shoes with no more than 2-3mm. I try to have a mid-foot strike instead of my heel. Calf pain has never been an issue for me. Altra shoes are mostly low to zero drop, and other makers have low drop models.

But everyone's anatomy and stride is different. Go to a good shoe store where they can analyze your gait and foot strike, and don't go cheap, buy the type of shoes they recommend.