It is quite well known for many people with diabetes that exercise can influence blood sugars.
It can influence it to go higher or to go lower.
While your response is individual, in my experience, intense physical activity can make blood sugars high (this is due to the effect of adrenaline and also the liver releasing glucose). The high may be followed by lows later.
Longer / less intense exercise may not have an immediate obvious impact at the time of exercise or it may make blood sugars go lower. I find long duration exercise will make my sugars go lower many hours later.
What do do?
1. Continue your exercise - the benefits surely outweigh the rise in sugars.
2. Don't take simple carbs before eating (However a small protein / fat snack may help keep things stable).
Your fasting blood sugar is on the high side if it is typically 140. Ideally blood sugars will be kept in the 'normal' range of 70 - 140, even better if 80 - 120 range, and fasting should ideally be < 95).
Reducing blood sugar may be done -
1. Exercise (sounds like you are doing your best on this front already).
2. Eating low carb / paleo / or even keto style. Diabetes is a condition of abnormal glucose / sugar metabolism, so it make sense then to reduce sugar load (includes simple and from starches) to help your body manage.
3. Medications. Speak with your Dr about adjusting your medications.
Hi Kumarqwp, that does seem strange. Here is an article from MedHelp.org about blood sugar, exercise and diabetes; typically your sugars are more in danger of going down with exercise than going up. Hopefully SuperSally88 our CL will come along; she is an avid exerciser and may have advice for you!