For hamstring growth
For hamstring growth, 45° back extension and good morning score the same.
45° back extension is easier on the joints; good morning keeps more of the work on the hamstrings.
Both are good choices, and they train the hamstrings differently. Using both across your week covers more of the muscle than either alone: in studies, varied exercises grew parts of a muscle that one exercise missed. (Fonseca et al., 2014; Costa et al., 2021)
The research score comes from these, scored by hand from the studies. Lifter scores appear once an exercise has 10 ratings. How scores work
45° Back Extension. A 45° hip extension grew the long head of the biceps femoris more than Nordic curls did in a 10-week study.
Good Morning. A big hamstring stretch, but the bar on your back makes it demanding on the lower back.
For lower-back growth, 45° back extension rates well ahead on our research criteria: easier on the joints, more of the work on the lower back.
For hamstring growth, 45° back extension and good morning score the same. 45° back extension is easier on the joints; good morning keeps more of the work on the hamstrings. Both are good choices, and they train the hamstrings differently. Using both across your week covers more of the muscle than either alone: in studies, varied exercises grew parts of a muscle that one exercise missed.
45° back extension is easier: it’s easy to learn, while good morning takes some practice.
45° back extension needs a GHD or back-extension bench, so for most people it’s a gym exercise. Good morning needs a barbell and a squat rack, so for most people it’s a gym exercise.
45° back extension: it rates Excellent for joint and recovery cost in our research rubric, against Fair for good morning.