Backpack Curl
Trains biceps first, with real work landing on forearms.
Muscle contribution per set
These are the weights Heatwayve's volume audit actually computes with — deliberately conservative, so compounds don't masquerade as full coverage. A 0.5 means a set counts as half a set for that muscle: meaningful help, not a replacement for direct work.
Tempo
Elbow flexion with an improvised load; the long eccentric and top squeeze compensate for a load you cannot fine-tune.
Load the pack with books; keep elbows pinned, squeeze at the top.
Derived from tempo research on this movement class.
How Heatwayve progresses it
Progresses by load in +0.5kg steps — small muscles, small increments, long patience.
Knowing the numbers is one thing; hitting them for fifty weeks is another. Open Heatwayve — it prescribes the weight, holds you to the tempo, and runs this arithmetic on every set you log so the week actually adds up.