How to Do the Norwegian 4×4 Workout Trend
via lifehacker.com
Short excerpt below. Read at the original source.
I first tried the Norwegian 4×4 workout a year ago, and since then, it has become a staple of my fitness routine. I don’t do it every week (some folks do), but it’s a workout I keep returning to whenever I want a hard, cardio-boosting routine that only takes about 40 minutes. It’s simple and […]