According to Dr. Levine, not only does the sedentary lifestyle increase the risks of cancer, heart disease, type 2 diabetes, but also for mortality: “Associations were strongest for cardiovascular disease mortality. The time spent sitting was independently associated with total mortality, regardless of physical activity level.” The last five words are disturbing implying that the risk cannot be, or is unlikely to be reversed (much like years of smoking) even with an hour of exercise during the day - which is what many of us are counting on.
Frequent sitters are also susceptible to "muscular issues" not only in activities like running and jumping but also "standing", and researchers suspect that this habitual stiffening of the muscles is the reason why the elderly lose their mobility and find it hard to move around. Sedentary behaviour also means that our LPL (lipoprotein lipase) - the enzyme responsible for breaking down fat - is significantly lower compared to those who stood more during the day. And as mentioned before, exercise did not appear to have an effect. Also, not surprisingly, prolonged sitting effected blood sugar levels and insulin production in a way that promotes obesity. In terms of mood, sedentary behaviour reduced the circulation of the "feel good hormones" which leads to depression.
What is very surprising from these results is that not only does regular exercise not have a significant positive effect on the aforementioned conditions, but that a healthy diet and exercise are NOT the only factors involved in weight loss & obesity - which is the precursor of heart disease and type 2 diabetes etc. The third essential factor they found which is needed for weight loss was "moving more throughout the day." Even just more standing helped weight loss, which leads me to think that Tai Chi is an ideal exercise to counteract the risks of such sedentary living, even at work.
Not only is Tai Chi convenient and perfect for moving throughout the day, the standing or moving exercises are concentrated, intense bursts of mindful exercise that bring so much more to, not only weight bearing, but structure , alignment, the interplay of muscles stretching and relaxing, as well as overall relaxation and the promotion of deep breathing - this isn't even including the benefits of a better circulating "Chi' system. And it can be done in whatever given space, even in work clothes and whenever, for short 5 minute break periods. Once the warm, good-feelings of "Chi" circulate, then the body feels remarkably comfortable and the mind is freshened to continue working. These feelings are much better than had I just walked around, got some coffee, or even stretched a bit.
I found that the best regime for me included frequent breaks from sitting, as well as two or three short sessions of exercise where I got up and did some upper body - shoulder stretches, neck stretches, lower back stretches followed by Taiji stances/or the stationary Tai Chi loosening exercises particular to the style I learn. The sessions ranged from 5 - 15 minutes per break, maybe 2 or 3 times a day. And in particular, doing a repeated portion of the set for 5 - 10 minutes, several times in the day could be very powerful. Finally before sleeping, I did a normal longer session where I had to work more intensely on loosening and relaxing the tension in my lower back. This led to a better sleep and energized feelings the next day. This regime was the best antidote to the terrible feelings of 10-12 hours of prolonged sitting working away on a computer & reinforced in my mind that Tai Chi can be an excellent short-term and long-term antidote to the risks of a sedentary lifestyle.