Hi Deville,
TBH, dogs don't get that much exercise from walking anyway. Is there anywhere safe you can take him to run off-leash? A fenced in area like baseball field at a local school, or a park? That would be better exercise to burn energy than walking - plus it's more fun to run around and play fetch too!
As for the loose leash walking, it sounds like you are doing a good job working with him using your techniques. Do you use any rewards at all? I used to keep a baggie of yummy treats with me and any time Red was at my left side, he'd get rewarded for it. He soon realized walking with me at my left side got him a cookie. I also used a prong collar to help with the loose leash walking. What kind of collar are you currently using? Flat nylon? Choke? I've found a correctly placed and used prong collar to really help with the loose leash walking. I also use the word "easy" when the leash starts getting too tight, then a give a small snap of the leash - not enough to turn his head (as this could cause damage to his neck), but enough so he knows he's being corrected. The second time I have to say "easy" means he has lost the priviledge to walk ahead of me and must walk at my left side. He must stay there until he is walking loosely, then he can go forward again. He has learned not to get to the point of me having to tell him "easy" because he will lose his freedom to walk out ahead and sniff things.
Every dog is different, this is just what has worked with me. I'm at the point that I can walk Red on a regular flat nylon collar now with minimal "easy" corrections. However, when I am in a crowded area of people and he is likely to get excited to meet people or other dogs, I still use the prong to maintain control so he can't drag me anywhere!
Hope that helps
Good luck!