I always played sport since I was 5 years old and I got into weight training and treadmill jogging in my 30's and was happy with my body shape. I 'bulked up' during the weight lifting years and since I turned 50 I don't lift weights so much. However, I have continued the running doing 6k four times a week on the treadmill. Now to the question. Why can't I lose weight even though my diet is good, I drink 4-5 litres of water per day and rarely drink alcohol, and I am exercising?