Race Comment Explainer

Original comment with matches highlighted:

held up towards rear, pushed along turning in, 3f out,

Matched phrases & meanings

Phrase	Meaning
Pushed along	The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Towards rear	Running near the back of the field.
tailed off	A definitive statement that the horse was finished and effectively out of the race
Weakened	The horse lost speed and dropped back through the field.
Held up	Intentionally raced patiently at the back to save energy.

Summary

The jockey started to urge the horse (hand-riding, not necessarily using the whip).
Running near the back of the field.
A definitive statement that the horse was finished and effectively out of the race
The horse lost speed and dropped back through the field.
Intentionally raced patiently at the back to save energy.