Agility vs Change of Direction

These terms are often used loosely, but sports science distinguishes them:

• Change of direction (COD) is the pre-planned physical ability to decelerate, change direction, and re-accelerate — the athlete already knows where they are going (e.g., a timed 5-10-5 or T-test run on a fixed pattern). It is governed by physical/technical factors: eccentric/braking strength, leg power, reactive strength, technique, and anthropometry.
• Agility is "a rapid whole-body movement with a change of velocity or direction in response to a stimulus." It adds a perceptual-cognitive component: visual scanning, anticipation, pattern recognition, and decision-making/reaction time, on top of the COD ability.

So agility = change-of-direction speed + perceptual-cognitive (reactive) ability. Two athletes with identical COD test scores can differ greatly in game agility because of how fast and accurately they read and react to opponents/ball. This is why training progresses from closed, pre-planned COD drills (cones, ladders, fixed patterns) to open, reactive-agility drills (mirror drills, react-to-coach/light/partner) that train perception and decision-making under the same movement demands.

• COD = pre-planned redirection; agility = redirection in response to a stimulus.
• Agility adds perceptual-cognitive factors (scanning, anticipation, decision/reaction).
• Agility = COD speed + reactive/perceptual ability.
• Equal COD scores can mean unequal game agility.
• Train closed (planned) COD first, then open (reactive) agility.

• cod-mechanics — the physical redirection component.
• reactive-agility — the perceptual/decision component and how to train it.
• cone-drills — examples of closed, planned COD drills.
• saq-programming — sequencing closed → open work.