Trans fat versus HDL?

Will 1 hour daily of hard biking create enough HDL to neutralize approx. 3 grams of trans fat in the single doughnut I have daily?

You see for every Kg of extra fat you have to walk about a 100 mile.
Regarding your question you should calculate amount of extra fat if you have any, than follow the instruction given above. you will burn up your entire lipid profile back to normal. that includes HDL AND LDL.

hmmm its not that simple. it depends completely on your health at the moment.
eat soluble fibre that reduces LDL

HDL? LDL? All cholesterol has the same density. You should do some reading into real medicine and not this profiteer's prophet.

This depends on many factors.
For a start, if your diet has enough carbs to provide the energy you need, no fat will burnt at all, and then the problems with trans fat start.
Trans fat is meant to imitate saturated fat, and the body will utilise it in the same way, but it will not behave in the same way.
One of the many important function of saturated fat is to be incorporated in the cell wall structure. When trans fats are utilised in this way rather than saturated fat, the cells become insulin resistant. This then can lead to all sorts of health problems.
It's ironic, given the way that saturated fat is demonised ,that if you have adequate saturated fat in your diet then small amounts of trans fats will not be harmful. It is best if you avoid trans fat all together, but if your diet and lifestyle is otherwise healthy, one doughnut a day shouldn't do too much harm.
HDL is n ot some superhero ridding your body of villains. High density lipoproteins ,among other things, transports used cholesterol from cells back to the liver, where the used cholesterol is then utilised as bile