There is undeniable evidence that the practice of yoga and other mindfulness based practices reduce the stress response in humans. Yoga requires little investment in time or money which makes it easily accessible for anyone, at any age, at any time.

Do Yoga With Me: This service offers free and paid yoga videos that are high quality. If you are new to yoga, then you can start with the beginners section though they have advanced videos and meditations as well.

Yoga with Adriene: Her mission is to connect as many people as possible through yoga. Her videos are hosted on Youtube. She offers numerous high quality yoga videos for all ages, levels, and body types. She has yoga videos listed based on time (under 10 minutes, 10-20 minutes, 20-30 minutes etc.) for those who are pressed for time.
Yome – Your Home for Yoga: Offers free and paid yoga instruction that can be searched based on practice level, length, style, and instructor.