First of all bro, you should not taking your BP and HR during your workout. The excess stress on your body from lifting, cardio, or pretty much any activity, will naturally increase HR, BP, body temp, and respirations. To get the most accurate reading you should take your vitals in the A.M. before any physical activity or consumption of any meals. Where do you think that feeling of vertigo came from. You didn't have it prior to your exercising. You increased your level of activity which will naturally increase HR, BP, etc. It is not uncommon for your BP to increase while cycling, but remember that it will increase that much more when you are active.