I exercize after dinner, around 8 or 9 pm. It really helps me with my evening bloodsugars.
I have been able to quit taking my night time NPH shot because of the exercise, but I also quit eating Bread, Rice and Potatos.
I have lost ~15 #s and I am feeling great. I go to bed with a BS of ~120 and wake up in the morning with a BS of 80 - 130.
I have been regulating my own insulin ever since my Endo screwed me up with Lantus and Humalog, That stuff about killed me. I went back on Regular and NPH (been on reg & nph for 34 years) and check my BS 4 times a day. I am doing pretty good with only 1 shot a day in the am.
I usually exercise for 1/2 hour 4 times a week. It seems that exercise can effect the bloodsugar for several days, but everyone is different and you will have to check your BS before and after you exercise to make sure you are not going too LOW (beware exercise at night can bring down your BS when you are sleeping) Watch out for the LOWS.