If you're a regular gym-goer, doing workouts that group similar muscle moves together or alternate them doesn't seem to make a difference in how much stronger or bigger your muscles get after 8 weeks.
Scientific Claim
In recreationally trained men, both synergist and nonsynergist resistance training schemes for 8 weeks are associated with similar increases in muscle strength (bench press and lat pull-down 1RM) and muscle thickness (triceps brachialis, biceps brachialis, and pectoralis major), with no statistically significant difference between the two approaches.
Original Statement
“Both groups displayed significant increases in muscle strength and thickness (NS and SN, p < 0.05), with no significant difference observed between the groups for the dependent variables assessed (all p > 0.05).”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The study uses causal language ('suggests individuals may benefit') and implies equivalence as a result of the intervention, but randomization status is unknown, so causation cannot be established. Only association can be claimed.
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 synergist vs. nonsynergist resistance training schemes produce equivalent strength and hypertrophy outcomes across multiple high-quality RCTs in recreationally trained individuals.
Whether synergist vs. nonsynergist resistance training schemes produce equivalent strength and hypertrophy outcomes across multiple high-quality RCTs in recreationally trained individuals.
What This Would Prove
Whether synergist vs. nonsynergist resistance training schemes produce equivalent strength and hypertrophy outcomes across multiple high-quality RCTs in recreationally trained individuals.
Ideal Study Design
A meta-analysis of at least 5 double-blind, randomized controlled trials comparing synergist (e.g., push/push, pull/pull) and nonsynergist (e.g., push/pull) resistance training schemes in 100+ recreationally trained men aged 18–35, with standardized volume, intensity, and frequency (3x/week, 3–4 sets, 8–12 RM), measuring 1RM strength and muscle thickness via DXA or ultrasound before and after 8–12 weeks of training.
Limitation: Cannot determine mechanisms or long-term adherence effects beyond the included trials.
Randomized Controlled TrialLevel 1bCausal equivalence between synergist and nonsynergist training schemes on muscle strength and hypertrophy in recreationally trained men.
Causal equivalence between synergist and nonsynergist training schemes on muscle strength and hypertrophy in recreationally trained men.
What This Would Prove
Causal equivalence between synergist and nonsynergist training schemes on muscle strength and hypertrophy in recreationally trained men.
Ideal Study Design
A double-blind, randomized controlled trial with 60+ recreationally trained men (age 18–35, 1–5 years experience) assigned to either synergist (push/push, pull/pull) or nonsynergist (push/pull) training for 8 weeks, 3x/week, matched for total volume and intensity, with 1RM bench press/lat pulldown and muscle thickness (ultrasound) as primary outcomes, and blinding of assessors.
Limitation: Cannot eliminate all confounding variables like diet or sleep without strict control.
Prospective Cohort StudyLevel 2bLong-term association between training scheme choice and sustained strength/hypertrophy outcomes in real-world settings.
Long-term association between training scheme choice and sustained strength/hypertrophy outcomes in real-world settings.
What This Would Prove
Long-term association between training scheme choice and sustained strength/hypertrophy outcomes in real-world settings.
Ideal Study Design
A prospective cohort following 200+ recreationally trained men over 1 year who self-select into synergist or nonsynergist training routines, tracking changes in 1RM and muscle thickness monthly, controlling for diet, sleep, and training volume.
Limitation: Cannot establish causation due to lack of randomization and potential selection bias.
Evidence from Studies
Supporting (1)
A Comparison Between Synergist and Nonsynergist Resistance Training Schemes in Recreationally Trained Men.
The study found that two different ways of doing weight training — one grouping similar muscle moves together and the other mixing them up — both made men stronger and their muscles bigger in the same way, with no real difference between them.