Zero-gravity combat training

Zero-gravity combat training or null-gravity combat exercises were a part of standard Starfleet Academy training.

James T. Kirk and Spock conducted null-gravity combat exercises together aboard the USS Enterprise (NCC-1701) a week prior to going on the Vedala expedition.

They later employed some of their null-gravity combat training during the expedition to combat Tchar, after he activated a gravity neutralizer in the Skorr temple, forcing those on the expedition to "fly and fight as a Skorr." 

In 2373/2063, when the crew of the USS Enterprise (NCC-1701-E) found out that that the Borg that had infested the ship were outside on the hull building an interplexing beacon on the ship's deflector dish, Captain Jean-Luc Picard asked Lieutenant Commander Worf if he had remembered his zero-g combat training. Worf revealed it made him sick to his stomach. Despite this, Picard, Worf and Lieutenant Hawk went onto the hull to stop the Borg.