The Study
Effects of Varied Versus Constant Loading Zones on Muscular Adaptations in Trained Men
This study tried two different ways of lifting weights and saw if they made people stronger or bigger. It found both ways worked about the same, but it didn't prove one causes better results than the other — just that they both helped.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Two groups of guys lifted weights for 8 weeks — one used the same weight every time, the other switched between heavy, medium, and light weights.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 554 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1For trained lifters, you don’t need to stick to one rep range — mixing it up might help a little, but sticking to one range works just as well.
- 2Both groups got stronger and bigger.
- 3The group that switched weights had slightly bigger gains in some areas, but not enough to say it was definitely better.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
International Journal of Sports Medicine
Year
2016
Authors
B. J. Schoenfeld, B. Contreras, D. Ogborn, A. Galpin, J. Krieger, G. T. Sonmez
Related Content
Claims (5)
Among young men who regularly lift weights, using a training routine that changes the number of repetitions across different sets leads to a slightly greater increase in maximum bench press strength than using the same repetition range throughout, but the difference is too small to be certain it is real.
In young men who regularly lift weights, training with different repetition ranges and training with a single moderate range for 8 weeks produce the same increases in muscle strength, muscle size, and endurance.
In young men trained in resistance exercise, using a range of repetition ranges (2–4, 8–12, and 20–30 reps) results in slightly greater increases in elbow muscle thickness and upper body endurance compared to using only 8–12 reps, but the difference is not large enough to be considered statistically reliable.
In young men who regularly lift weights, two different training styles—changing exercises versus sticking to the same ones—both improve muscle endurance equally after 8 weeks.
In young men who regularly lift weights, following either a varied or a consistent weight training routine for 8 weeks leads to similar increases in muscle thickness.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.