I started biking to lose weight this year. I'm 5'8 175 pounds would like lose 25. I absolutely love it! I bought a Trek mountain bike. I'm at 20 miles, average speed about 12. I do go like 14-15 usually but overall its 12 with my app on my phone with my water breaks and getting stuck around crowds as I bike on the lake. Is this good so far my progress?? I'm so exhausted when I'm done and I know I'm not in good shape. My legs feel tighter. And I have 2 bad knees and those get sore but I really try to focus on my muscles when biking but heard this is good for bad knees. Will I achieve weight loss or just looking trimmer overall? I go 4 times a week. This is my 4th week and I only dropped 3 pounds and I do eat really well. Any advice? I would like to bike longer and biking for good causes etc.