This riddle sounds as though it is asking about something with almost no weight. But the clue is really about something a person can “hold” only for a limited amount of time.
Answer: Your breath.
You can make your breathing light, and you can also hold your breath, but even a very strong person cannot hold it indefinitely. Eventually the body forces you to breathe again.
The riddle works because “hold” is not being used in the physical sense of carrying an object. Instead, it refers to the familiar expression “hold your breath.”
