Discussion Guide — Chapter 16

Six prompts, roughly in the order the material supports them. Each includes what to listen for.

Prompt 1 — "The mechanism was right and the drug didn't work. How is that possible?"

Open the session with this, before any explanation. It reframes the whole chapter as a puzzle rather than a set of conclusions.

Listen for: students who immediately reach for execution failures — wrong dose, wrong patients, underpowered. That is the correct first instinct and should be praised, then complicated: the pattern recurred across sponsors and mechanisms, which is what rules out execution. Listen also for the student who says "maybe the mechanism wasn't as important as they thought" — that is closer, but still not right, because the drugs did add mass. The answer you are steering toward is that the failure was in an unexamined step of the reasoning, not in the biology or the trials. If nobody gets there, leave it open until after §16.6 and return to it.

Prompt 2 — "What does the Belgian Blue actually prove?"

Listen for: the confident early answers ("it proves blocking myostatin builds muscle") and let them stand for a minute before probing. Then push: proves it in whom, at what life stage, with what intervention? The distinction you want surfaced is developmental knockout versus adult blockade — and if a student reaches hyperplasia versus hypertrophy on their own, stop and make the room appreciate it. Watch for the second-order move, which is rarer and better: a student who notices that nobody measured what the cattle could do. Also listen for whether anyone raises the welfare costs unprompted; if not, raise them yourself, without editorializing.

Prompt 3 — "You're a regulator in 2013. A sponsor shows you a clear increase in lean body mass on DXA and asks for accelerated approval. What do you say?"

Best run as a role-play with two or three students as the sponsor and the rest as the agency.

Listen for: whether the sponsor team argues from patient need and trial feasibility (both legitimate, both powerful) and whether the agency team can articulate the validation requirement rather than just saying no. The failure mode is an agency team that sounds obstructive; push them to explain what would satisfy them. The best exchanges end with both sides agreeing on what evidence would settle it — which is the point of the whole rating system.

Prompt 4 — "Your own training experience says mass and strength go together. Why is that not evidence?"

The hardest prompt in the set, and the most valuable. Expect resistance.

Listen for: whether students can locate the confound themselves — that training supplies the stimulus at every rung simultaneously, so the correlation in personal experience is evidence about training rather than about mass. Many rooms need a nudge. A useful one: "What did you change, and how many things did it affect?" Listen also for the student who offers a genuine counterexample from their own experience (a period of size gain without strength gain, or the reverse); those are gold, and worth more class time than anything you had planned.

Prompt 5 — "The sarcopenia field moved its own definition away from mass toward strength. What does it cost a research field to do that, and why did they do it anyway?"

Listen for: recognition that this is expensive — it invalidates prior work, breaks comparability with older studies, and requires people to concede that the measurement in their discipline's name was the wrong one. Then the payoff: they did it because mass predicted outcomes poorly. This is the strongest independent support for §16.6 available, precisely because it comes from a field with no stake in the peptide argument. Push students to say what the equivalent revision would look like in a field they care about.

Prompt 6 — "A friend asks what you think about IGF-1 LR3. What do you actually say?"

Close with this. It converts the chapter into something usable and it surfaces tone problems that content questions hide.

Listen for: whether students ask anything before advising. The best responses begin with questions — what are you hoping it does, what has the clinic told you, what else are you taking — rather than information delivery. Listen for the three substantive points: the human evidence for benefit does not exist; the long-term risk is unquantified rather than known to be small; and product identity and clinician involvement matter. Listen hardest for tone. A student who is technically correct and condescending has failed the exercise, and the room usually knows it before you say so. If the conversation gets moralizing, stop it and ask the room how they would feel receiving what was just said.