Cable Machines & Functional Trainers

A cable machine routes a weight stack through a pulley to a handle on a cable. A functional trainer is the dual-adjustable-pulley version: two stacks with pulleys that move up and down a column, so you can set almost any line of pull.

Pros

• Multi-plane and adjustable angle — unlike most machines, you can pull/press high, low, horizontal, or diagonal, and train rotation and chops (see medicine-ball-rotational-throw). This makes it far more "functional" than a fixed single-plane machine.
• Constant tension through the full range — the cable keeps load on the muscle even where a free weight would unload (e.g., top of a flye or lateral raise), useful for hypertrophy and for the positions-of-flexion approach.
• Smooth and joint-friendly; easy, fast stack changes; usually no spotter.
• Standing cable work demands trunk/anti-rotation stability (see core-stability-vs-strength).

Cons

• Setup time — choosing pulley height, handle, and stance for each exercise.
• Less maximal loading than a barbell for big compounds.
• Large footprint and high cost; mainly a gym/full-home-gym item.
• The cable's line of pull still constrains the path more than a true free weight.

resistance-bands are the portable, low-cost stand-in for cable work (variable rather than constant tension).

• Pulley + stack; functional trainer = dual adjustable pulleys for any line of pull.
• Trains multiple planes including rotation; constant tension through full ROM.
• Smooth, fast to change, usually no spotter.
• Cons: setup time, limited max load, footprint/cost.

• selectorized-machine — related stack-based machine (fixed path).
• resistance-bands — portable substitute for cable tension.
• positions-of-flexion — constant tension suits this method.
• medicine-ball-rotational-throw — cable chops/rotations.
• core-stability-vs-strength — standing cable work loads anti-rotation.