The shred is a few minutes of cardio, strength, and something else, but I've forgotten!! Type 30 day shred into YouTube, and you will see a few clips of it. When I see the clips on YouTube I thought " oh that's not looking too hard " but boy was I wrong!! My thighs are still in pain now.
I also do the C25K challenge too, that's a 9 week running/jogging/walking challenge, which is only 20-30 minutes 3 times a week. That one is quite popular on here too