Determining Your Muscle Fibre Ratios


We’re big fans of applying scientific research to training, nutritional and recovery protocols here at ABC fit. But undergoing a painful and scrutinising muscle biopsy to determine your dominant fibre type is perhaps a little too extreme. If your main goal is hypertrophy knowing your own individual muscle fibre ratios will eliminate any guesswork and allow you to programme workouts accordingly. This is what training smarter is all about. There are two main muscle fibre types that we try to stimulate when training for hypertrophy – fast twitch and slow twitch. Both respond to a different stimulus of training. Every individual will have a different ratio of both. So with the muscle biopsy out of the window, try this simple test to get a better idea of your dominant muscle fibre type.

The 80% reps test

The procedure for the muscle fibre ratios test is simple, after a warm up take a weight that is of 80% of your maximum and perform as many reps as you can with good, controlled form. Choose from the recommended exercises below. Then see the table to interpret your results.

Quadriceps: barbell back squat
Hamstrings: lying leg curl
Calves: seated calf raise
Chest: dumbell bench press
Back: bent over barbell row
Shoulders: seated dumbell shoulder press

Muscle fibre ratios and the 80 percent rep tableOn a final note, bear in mind for hypertrophy you should be stimulating every fibre possible. So if you scored an average of 1-3 reps on the test, that doesn’t mean you have to lift heavy with low volume every workout for the rest of your training career, but it should be your main focus.