There have been smart insoles before, but Nurvv is betting that its shoe companions could be particularly helpful if you're a runner. Its Nurvv Run insoles pack 32 sensors that, along with mobile apps and included GPS trackers, provide coaching both during and after runs. You can get updates on standard stats like cadence, step length and overall pace while you're mid stride thanks to audiovisual and haptic feedback. However, you can also venture into the app post-run to look at minutiae like your pronation (foot roll) and foot strike (how much of the forefoot hits the ground). You'll know whether a change in technique leads to practical gains.