Measuring progress in fitness training can be achieved through various methods such as tracking body composition, strength gains, and cardiovascular endurance. Keeping a workout journal allows individuals to document reps, sets, and exercise duration, helping identify trends over time. Progress can also be evaluated through fitness assessments, like timed runs or functional movement tests. Additionally, taking progress photos and monitoring how clothes fit are practical ways to visually assess changes, fostering motivation and commitment to long-term fitness goals.