The store description is both the definition of Muscle and the edge of what is confirmed: lift weights to gain Muscle and lift Karens faster. That is a speed effect. It is not a published gate that says a particular Karen needs a particular number.
What each named system changes
| System | What the description assigns to it |
|---|---|
| Muscle | Lifting Karens faster |
| Weights | The training items that raise Muscle |
| Auras | Lifting weights faster |
| Chests and rare weights | Even more Muscle than ordinary lifting |
| Speed upgrades | Traveling faster |
Auras are not described as adding Muscle. They shorten the training action. Speed does not raise Muscle per hour of lifting. It shortens the walk between weights, chests, and Karens. Buying Speed because lifts feel slow does not match the description.
Requirements that are not on record
A requirement would be a number you must reach before a Karen can be lifted at all. The line about Karens being way too heavy is flavor in the description, not a stat check with a value. No individual Karen is named with a Muscle figure, and no too-heavy prompt is quoted in official material.
That absence is not proof the game has no gates. It means there is no verified threshold to copy. If a chart lists exact Muscle for each Karen and the number is not on the Karen in front of you, treat the chart as unverified.
How to judge a training session
No official source describes a Muscle HUD, menu, or label. Do not hunt for a screen this site cannot point to. Use the effect the description does name: if the same Karen goes up faster than before, the training changed something. Routes that raise the stat are in how to gain Muscle. How throws fit the rest of the run is in how to beat Karens.