Muscle always burns fat..

Resistance training... we aren't designed for cardio anyway-hense the catabolic state we go into. Meaning break down (eats muscle etc)

You can do resistance training to maintain muscle mass and increase strength with out gaining size. You go for 'reletive strength'

Things like teaching the moto unites to syncronize better there for firing more of the muscle at the same time-so you can move faster and stronger and more powerfully yet you haven't added muscle mass. Or teaching the nervous system to recruit more of the motor unites (same response).

Most of the strength training comes from body building...not thje place athletes want it from. (even if you want to go for 'maximum strenth'-which will also give you size).

Obviously eating/sleeping/drinking (water) right play large factors too.

Anaerobic exercise will be good for fat loss too 9more appropriate for MuayThai conditioning too imo

Basically anything that speeds up or improves the metabolism will burn fat

going overly catabolic doesNOT improve the metabolism.. Over doing cardio will cause problems. (how many aerobic instructors are fat or soft??? loads)