I am a hard gainer and small eater. I have been trying to change that, to get used to eating more, but so far I am losing the battle. My body refuses food when it is not hungry, which happens usually twice a day only :( Could anyone share their opinion/experience about my workout routing for such a situation? Note that this post is not about how I can eat more. It is about how I should workout if I am unable to eat a lot during the day. Thanks!
I know your question mentions this is not about food, but I think you have a fundamental misunderstanding. If you cannot even eat a maintenance diet, you should not be burning even more calories on exercise. An alternate question title could have been:
"My car has run out of gas, how do I keep driving?"
Obviously this question would be absurd. But that's exactly what you're asking about your own body.
If you cannot eat, you need to find out why. What is your diet? Do you like the foods you are eating? Are they calorie rich or mostly water? How often are you trying to eat? Can you eat small amounts and more often? Could you drink a mass gainer drink?
In my opinion, if you cannot eat enough food to gain weight you should not be exercising at all. If you continue to exercise, you will just lose weight, which seems like the opposite of what your goal is.
If you can not eat enough, if you try going to a nutricionist explaining your problem and he can't give you a solution junt by eating normal food, he might tell you to take carb-shakes. They have a high ratio between calories and volume. I'm not telling you just to drink gainers all day long. Just try to combine it with a healthy high caloric diet. If you can't eat enough, any execice you do would burn more fat and muscle down. However, if you achieve eating more you might try to reduce cardiovascular exercise and focus on weights just to minimize catabolism.