Good morning exercise: muscles worked and setup

The good morning works the hamstrings first, with the glutes and back as secondaries — the Zyra Workouts catalog makes it the only barbell hinge filed under hamstrings rather than back. Mechanically it is a Romanian deadlift with the bar on your upper back instead of in your hands, and that single change is why it is so much lighter and why the setup deserves care.

Muscles worked

The hamstrings and glutes extend the hip to bring the trunk back up; the back muscles hold the spine in one shape while the trunk tips forward. Three working sets add 3 to the hamstring landmark (10 a week) and 1.5 each to glutes (10) and back (14).

Why the bar position matters

Turning force at the hip is load × horizontal distance from the hip. In a Romanian deadlift the bar hangs straight down from the shoulders and slides along the legs, so it stays close to the hips. In a good morning the bar is on the upper back, and as the trunk tips toward horizontal that bar ends up far in front of the hips — a long lever. The same 60 kg therefore demands far more from the hamstrings and back in a good morning than in an RDL. This is why good mornings are done with a fraction of the RDL load, and why the load-chart buckets for the row start at 40 kg. Arithmetic, not a trial result.

Setup and execution

1. Bar. High on the traps, as for a high-bar squat, hands close enough to pin it in place. It must not roll when you tip forward.
2. Stance. Roughly hip width, knees soft — bent a few degrees and then fixed, as in an RDL.
3. Brace. Big breath, ribs down, back set before anything moves.
4. Hinge. Push the hips straight back and let the trunk tip forward, bar travelling in a straight line down. Stop where the hamstrings stop you — often around 45° of trunk lean, sometimes near horizontal with practice.
5. Return. Drive the hips forward to stand tall. Do not bend the knees further to "help"; that turns the lift into a squat.

Start with the empty bar even if your RDL is heavy. The lever makes the numbers feel unfamiliar, and the first logged session is what the progression engine needs before it will recommend anything.

Rep and RIR targets by goal

Compound exercise, compound table:

The rep ceiling is the number the app compares your last set against: the midpoint of the rep range plus the RIR target (round((min + max) / 2) + RIR). RIR is reps in reserve — how many more reps you could have done. These targets are the app's defaults, not a law; a program you build yourself can set anything. Default rest is 120 s. Many people keep good mornings in the 8–12 row regardless of goal, simply because a heavy triple with a long lever is harder to keep identical rep to rep — that is a coaching preference, not an app rule.

How progression steps on this exercise

Barbell: one pair of the smallest plate, 2.5 kg with 1.25 kg plates in your gym profile. On the general target (8–12 @RIR 2, ceiling 12): 40 kg × 13 → 42.5 kg × 8; 40 kg × 10 → hold; 40 kg × 7 → 37.5 kg × 8. The 1RM page estimates a maximum from any set, but a good-morning single is not something most people test — use the estimate as a trend line. This is arithmetic from the progression engine, not a trial result.

Alternatives

The swap list keeps hamstrings as the primary. Three rows qualify:

The barbell RDL is the nearest relative in the gym but the catalog files it under back, so the ranked swap does not offer it; use the search if you want it.

The short version

Hamstrings primary; glutes and back secondary. An RDL with the bar on the back — same hinge, long lever, light bar. Compound targets, 120 s rest, 2.5 kg steps. Empty bar first, fixed knee angle, hips back, stand tall. Educational overview only — training guidance, not medical advice.