FormaGet FormaDirect and indirect sets should not be treated as identical.
Compound exercises train more than one muscle, but involvement is not the same as an equal dose. A useful weekly view preserves primary and supporting roles without claiming one fraction is universal.
Published and last reviewed September 14, 2026 · 7-minute read
Examples by movement
| Exercise | Clear direct context | Supporting context | Why the count varies |
|---|---|---|---|
| Bench press | Chest pressing work | Triceps and anterior deltoid | Grip, technique, range, and anatomy affect contribution |
| Lat pulldown | Vertical pulling for lats | Elbow flexors and scapular muscles | Grip, torso angle, and execution change demands |
| Preacher curl | Elbow-flexor work | Forearm and stabilizing contributions | Resistance profile and joint position matter |
| Leg press | Quadriceps and hip-extensor work | Contribution differs by setup | Foot position, depth, machine, and technique matter |
The labels are tracking categories, not direct measurements of local muscle force or growth.
What the 2026 analysis found
Pelland and colleagues classified contributing sets as direct or indirect relative to the measured strength or hypertrophy outcome. They compared three indirect-set methods: count each indirect set fully, count it as 0.5, or exclude it.
Total method
Indirect sets were counted as one. This assumes the same contribution as direct work inside the model.
Fractional method
Indirect sets were counted as 0.5. The analysis reported the strongest relative evidence for this approach.
Direct-only method
Indirect sets were counted as zero. This removes supporting work from the modeled dose.
The result supports distinguishing the two categories. It does not establish a universal 0.5 coefficient for every muscle, exercise, technique, lifter, or app.
Research classification is not a finished exercise map
Classifying sets relative to an outcome across published studies is different from assigning contribution weights to thousands of exercise and muscle combinations. Forma publishes the rationale for recognizing supporting work, but its exercise mappings and weights remain proprietary.
A practical manual approach
Record direct work
Start with challenging sets where the muscle is a clear primary target.
List supporting work
Identify compound sets that involve the muscle meaningfully.
Avoid false precision
Do not assume every supporting set contributes an exact universal fraction.
Review outcomes
Use performance, recovery, technique, and repeated history to interpret the total.
Frequently asked questions
What is a direct set?
A direct set is one in which the muscle has a primary, specific role relative to the exercise and outcome being tracked. The classification depends on the movement and the muscle being analyzed.
What is an indirect set?
An indirect set is one in which a muscle contributes meaningfully but is not the primary target. Examples can include triceps work during pressing and elbow-flexor work during pulling.
Should an indirect set count as half a set?
A 2026 meta-regression found the strongest relative evidence for a fractional method that counted indirect sets as 0.5 in its models. That population-level result does not prove that every indirect set in every exercise is exactly half a direct set.
How does Forma count compound exercises?
Forma can credit primary and supporting muscles in its weekly volume view. Its exercise mappings, contribution weights, thresholds, confidence logic, and recommendation rules are proprietary and are not published on this page.
Primary references
The 2026 analysis that compared total, fractional, and direct-only indirect-set methods.
A 2021 review explaining why the appropriate volume measure depends on the comparison.
Continue the volume library
See compounds and isolations in one muscle history.
Forma connects direct and supporting-muscle work with sets, repetitions, load, optional RIR, progression, and recovery context.
Read the public methodologyDownload Forma