In your practice, if you want to make some effort, your effort should be directed to keeping your posture right, or to have deep breathing, or to put some strength in your tummy. This is all that you should do, but as you have experienced, to have right posture and to have right breathing are not different things. It is the same practice. —Excerpt from Shunryu Suzuki lecture - 68-01-18 - as found on shunryusuzuki.com edited by PF. Go to instagram.com/cuke_archives or cuke.com/ig for links to the full Shunryu Suzuki lecture and the source of the photo.
Shunryu Suzuki at Sokoji during zazen, mid-sixties