One of the best things that I have ever incorporated into my fitness routine is yoga. The go to yoga that I generally prefer is hot yoga... Yoga in about 100 degrees for ninety minutes. This type of yoga helps improve flexibility, strength, and mental stamina (mental stamina is an opinion, it has not been proven). Even though I love hot yoga, I only go about 2-4 times per month since it can be a bit pricey and intense. For those days when yoga is on the mind but hot yoga is not a real option, I turn to a podcast called Yogamazing by Chaz. His classes and directions are great, plus, he says funny things... I always like a little laugh with my yoga! My personal favorite is one done way back in 2008 called Warrior Flow. It totally works your bum and arms, it is awesome and I am still in love with it after four years.
Another one of my favorites is a podcast called Yogajournal. The instructors here are rotated so you can mix it up or pick a favorite and stick with them. The Move and Sweat and Twist and Detox are great when done together, you will definitely be feeling it in your core after these!
Two great things about these podcasts is that both are video and they are available as subscriptions on YouTube and iTunes. No need to be a yoga pro, they show and tell all the positions!