Final answer:
Free fatty acids (FGA) are hydrophobic molecules derived from the breakdown of triglycerides in the body. They have an affinity for a specific substance, making them 'philic'. FGA can have both short and long duration of use as an energy source depending on the specific need and availability of other energy sources.
Step-by-step explanation:
FGA stands for Free Fatty Acids, which are molecules derived from the breakdown of triglycerides in the body. Free fatty acids are hydrophobic, which means they are repelled by water. The term 'philic' refers to the affinity of a molecule towards a particular substance. Therefore, 'FGA are very philic' means that free fatty acids have an affinity for a specific substance.
In the context of duration, it is important to understand that free fatty acids can be used as an energy source in the body. Depending on the specific need for energy and the availability of other energy sources, free fatty acids can have both short and long duration of use. For example, during low-intensity exercise, the body relies more on free fatty acids for energy, resulting in longer duration of use. Conversely, during high-intensity exercise, the body predominantly uses other energy sources, resulting in shorter duration of use of free fatty acids.