For the outer calf and deep calf muscle, it doesn’t seem to matter much whether you do straight-leg or seated calf raises — both work about the same.
Scientific Claim
The lateral gastrocnemius and soleus muscles in resistance-trained individuals show no clear hypertrophic advantage from either straight-leg or seated calf raise exercises after 8 weeks of training, based on equivocal Bayesian posterior probabilities.
Original Statement
“Regarding the triceps surae, the point estimate favored straight-leg plantar flexion for muscle thickness of the medial gastrocnemius (P = 0.991), with equivocal results observed for the lateral gastrocnemius and soleus.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
probability
Can suggest probability/likelihood
Assessment Explanation
The authors correctly describe results as 'equivocal,' and the claim uses 'no clear advantage' to reflect probabilistic neutrality. No overstatement is present.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Systematic Review & Meta-AnalysisLevel 1aWhether exercise selection has no consistent effect on lateral gastrocnemius or soleus hypertrophy across studies.
Whether exercise selection has no consistent effect on lateral gastrocnemius or soleus hypertrophy across studies.
What This Would Prove
Whether exercise selection has no consistent effect on lateral gastrocnemius or soleus hypertrophy across studies.
Ideal Study Design
A meta-analysis of 15+ RCTs comparing straight-leg vs. seated calf raises in resistance-trained adults, using MRI-measured lateral gastrocnemius and soleus thickness as primary outcomes, with standardized protocols and 6–12 week duration.
Limitation: Cannot determine if longer durations or higher volumes might reveal effects.
Randomized Controlled TrialLevel 1bIn EvidenceCausal evidence that lateral gastrocnemius and soleus hypertrophy is unaffected by exercise selection.
Causal evidence that lateral gastrocnemius and soleus hypertrophy is unaffected by exercise selection.
What This Would Prove
Causal evidence that lateral gastrocnemius and soleus hypertrophy is unaffected by exercise selection.
Ideal Study Design
A double-blind, crossover RCT with 40 resistance-trained adults (age 20–35), randomized to 8 weeks of straight-leg or seated calf raises (3x/week, 4 sets, 10–15 reps), with MRI-measured lateral gastrocnemius and soleus thickness as primary outcomes and contralateral leg as control.
Limitation: Cannot rule out effects beyond 8 weeks or with higher training volumes.
Prospective Cohort StudyLevel 2bReal-world association between exercise selection and lateral gastrocnemius/soleus size.
Real-world association between exercise selection and lateral gastrocnemius/soleus size.
What This Would Prove
Real-world association between exercise selection and lateral gastrocnemius/soleus size.
Ideal Study Design
A 2-year prospective cohort tracking 200 resistance-trained individuals who self-select straight-leg or seated calf raises, measuring lateral gastrocnemius and soleus thickness via ultrasound every 6 months while controlling for volume and diet.
Limitation: Cannot control for confounding variables like ankle mobility or footwear.
Evidence from Studies
Supporting (1)
Exercise Selection Differentially Influences Lower Body Regional Muscle Development
The study found that for two calf muscles (lateral gastrocnemius and soleus), doing calf raises with straight legs or bent knees didn’t make one better than the other for muscle growth after 8 weeks — which is exactly what the claim says.