Yes, there are good reasons to practice differently during your menstrual period!
The practice of yoga aims to increase our self-awareness and the best possible health for our body. Yoga poses are practiced not only to bring the physical body to a healthy state of balance, but also to improve our mental and physiological states. According to Pixie Lillas (see article link below), "The aim is to create the best possible environment for nature to follow its course and to bring into balance any disturbances, mental or physical, which may occur during the days before or during menstruation."
Poses that are often contra-indicated during menstruation are:
- Unsupported backbends
- Strong twists
- Abdominal poses
- Possibly unsupported standing poses
Unsupported backbends can over-stimulate the system at a time when we want to soothe the system.
Strong twists and abdominal poses tend to irritate the system rather than soothe it (if you're cramping, do you really want to do Boat Pose or Noose Pose???)
Some woman are more tired during menstruation, and unsupported standing poses will further deplete their energy.
Poses that are suggested for the menstrual cycle include calming, cooling poses such as supported forward bends, and quiet energy-boosting poses like supta virasana and supta baddha konasana (click Menstrual Sequence for pictures of these poses).
Two well-written articles on the practice of yoga during menstruation are (click on the title) :
Why are some poses not practiced during menstruation? by Pixie Lillas, (Advanced Iyengar Yoga certification, Sydney, Australia)
Inversions and Menstruation by Mary P. Schatz, M.D.
When you come to class while you're menstruating, you can let me know beforehand, especially if you're experiencing extra difficulties (cramping, tiredness, headache, bloating). Or you can just tell me that you're not inverting or that you'd like a quieter sequence during class. I'll suggest the appropriate poses for you.
What happens if you ignore the "menstrual recommendations"? Maybe not much, especially if you're not a strong practitioner (i.e. if you don't have much of a yoga practice in between classes). But then again, you may feel more physically or mentally drained, or you may see an undesirable change in your flow or other menstrual symptoms. Consider giving yourself permission to change your practice during your period, whether at home or during class, to help to "recharge your batteries" and to soothe your nervous system.