Throw your heart over the bar and jump over it.

This statement means if you are passionate about something, your heart will give you tremendous energy to cross over the bar, even it is set very high. But without putting your heart into the goal, you may have difficulty following it through.
The heart refers to our passion and enthusiasm. You probably knew that in whatever we do, if we do not put our heart into it, we would not do it well and it may not last long. This applies to cooking, dancing, writing, exercise etc.
Passion is an intense emotion of love that comes from our subconscious mind.