I have just completed my yoga teacher training in India, and one of my favourite experiences was where in one of our final asana practices we did 60 rounds of Classical Surya Namaskara (120 rounds). I thought it would be hard physically and mentally but I loved every moment of it. It took 90 minutes to complete and I thoroughly enjoyed doing it, so much so I am going to commit myself to do doing this practice once a month, as i feel both my body and mind truly benefited from the practice.
You many have also have heard the charity of Yoga Stops Traffic, this is were people get together and complete 108 rounds of sun saluations in aid of charity, see Website. This saturday, 9th March 2013, many people across the world will get together and complete 108 rounds and I will also be completing 108 as well.
Surya Namaskara is a flow of 12 asana changes which if breath and movement become synchronised it feels like a flowing meditation and is good for increasing body awareness, flexibility, core strength, and stability but it is also good at relieving stress and calming the mind.
Here is a little video of my teacher, Bharath Shetty, demonstrating one round of Surya Namaskara, the classical version. For info, here is a link to the technical description of each asana at each stage, Surya Namasakara Technique
Once you have perfected the flow of movement and technique you can then start synchronising your breath with each movement, it is at this point that I start to relax and enjoy the movement of the flow. It helps brings my mind into the present moment and bring my focus back to the movement of each asana and breath. Once this stage has been mastered of breath and movement then also other aspects can be built into the flow, including mudras, bandhas and mantras in order to help advance the practice further.
I highly recommend warming up with around 12 rounds, i.e. 24 rounds in your own self practice. Once you feel comfortable and strong you can then build up your strength slowly by increasing the number of rounds, but only if you feel comfortable, do not force the movement you should feel relaxed but focused in each asana change… and then maybe you never know….eventually 120 rounds!