That's why PS created a 30-day plank challenge you can do at home. The goal of this plank challenge is to target multiple parts of your core (obliques, abdominals, back, glutes), along with a bit ...

The plank is, after a short time ... By day three I was up to three sets of 12, with 30 seconds between efforts. This didn’t seem much of an improvement, but the lateral raise was proving ...