Plenty of people can hold a standard front plank for over a minute without breaking a sweat. Some can even hold a plank for hours. The record is currently 4 hours and 26 minutes. While that’s pretty amazing, it’s pretty inefficient for your training.
The High Tension Plank or RKC Plank, is a great anti-extension (avoiding extension in the lumbar spine) exercise for training the anterior core and pretty much your entire body. The High Tension Plank is a lot more intense than your basic front plank and requires a lot more muscle activity.