In addition to resistance training, are you spending time doing some form of cardio exercise to burn fat and get rid of that pot belly? If your primary goal is to bulk up, you are making a big mistake. It IS counter-productive trying to gain muscle and lose fat at the same time. Your diet and training program should be tailored to “gain muscle” or “lose fat”, not both, because they have very different requirements.
As a hard gainer, the last thing on your mind should be “fat loss”. One of the attributes of being an extreme ectomorph is that you don’t put on weight easily. Although it can make it tougher to gain more muscle, you will actually be glad you have this body type when you begin to increase your calorie intake to gain mass, because you can eat anything and not put on fat.
If your goal is to gain weight then don’t do any cardio exercise at all, the calories you burn during the cardio workout will result in you having to consume even more calories to make up for the calorie deficit. The focus should be on gaining muscle so you can tailor your diet and training routine to achieve this goal. Stick to doing weight training three days a week, working in the 8 to 12 rep range, and make sure you’re eating to gain muscle not to bulge.
I wouldn’t even do cardio training on your off days, cut it out all together. Too much cardio exercise will increase cortisol levels in your body, which is catabolic, meaning it breaks down muscle tissue. That is why you would never see a bodybuilder doing any form of cardio workout – it is counterproductive to muscle gains.
If you are that desperate to get lower body fat levels so you have a more ripped looking appearance, then you can integrate some cardio into your weight training program once you have gained your desired weight. But as I said this should be the last thing on your mind when you just start training and want to pack on the pounds.
The only cardio I would recommend is some light cardio before working out to warm up the muscles you are going to use, but even this is not really necessary and can be achieved by doing warm-up sets instead.
Don’t get me wrong, there are a wide variety of health benefits you receive from doing cardio, it’s just something which you will want to put on hold whilst your goal is to gain weight.