When two different ways of lifting weights are adjusted so that the total time your muscles are under strain is the same, both ways lead to about the same strength gains and muscle growth in people who haven’t trained before.
Scientific Claim
In untrained men, resistance training protocols equalized by time under tension (36 seconds per set) are associated with similar increases in maximal strength (1RM) and total muscle cross-sectional area of the pectoralis major and triceps brachii after 10 weeks of bench press training, regardless of whether repetitions were performed at 3-second or 6-second durations.
Original Statement
“Protocols 3s and 6s showed no differences in the increase of total and regional muscle cross-sectional areas... Both experimental groups had similar increases in the 1RM test.”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The abstract implies equivalence and uses language like 'promote similar gains,' but randomization is not explicitly confirmed, 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 equating time under tension across resistance training protocols consistently leads to similar strength and hypertrophy outcomes across diverse populations and protocols.
Whether equating time under tension across resistance training protocols consistently leads to similar strength and hypertrophy outcomes across diverse populations and protocols.
What This Would Prove
Whether equating time under tension across resistance training protocols consistently leads to similar strength and hypertrophy outcomes across diverse populations and protocols.
Ideal Study Design
A meta-analysis of 20+ randomized controlled trials comparing resistance training protocols matched for time under tension (e.g., 30–40s/set) versus matched for repetitions or total volume, in untrained adults aged 18–40, measuring 1RM and muscle cross-sectional area via DXA or ultrasound after 8–12 weeks, with standardized nutrition and supervision.
Limitation: Cannot establish individual-level causality or account for unmeasured confounders across studies.
Randomized Controlled TrialLevel 1bIn EvidenceWhether time under tension, when held constant, produces equivalent neuromuscular adaptations compared to differing repetition schemes.
Whether time under tension, when held constant, produces equivalent neuromuscular adaptations compared to differing repetition schemes.
What This Would Prove
Whether time under tension, when held constant, produces equivalent neuromuscular adaptations compared to differing repetition schemes.
Ideal Study Design
A double-blind, randomized controlled trial of 120 untrained men aged 20–35, assigned to three groups: 3s TUT (12 reps), 6s TUT (6 reps), or control, performing bench press 3x/week for 10 weeks with 36s TUT/set, 50–55% 1RM, 3-min rest, measuring 1RM and pectoralis/triceps CSA via MRI at baseline and endpoint.
Limitation: Cannot generalize to trained individuals, women, or other exercises without additional trials.
Prospective Cohort StudyLevel 2bWhether natural variations in time under tension during resistance training predict long-term strength and hypertrophy outcomes in real-world settings.
Whether natural variations in time under tension during resistance training predict long-term strength and hypertrophy outcomes in real-world settings.
What This Would Prove
Whether natural variations in time under tension during resistance training predict long-term strength and hypertrophy outcomes in real-world settings.
Ideal Study Design
A 1-year prospective cohort of 300 untrained adults tracking their self-selected resistance training routines, measuring TUT per set, repetitions, load, and changes in 1RM and muscle CSA via ultrasound, controlling for diet, sleep, and adherence.
Limitation: Cannot rule out confounding by self-selection bias or adherence differences.
Evidence from Studies
Supporting (1)
Equalization of Training Protocols by Time Under Tension Determines the Magnitude of Changes in Strength and Muscular Hypertrophy
The study gave untrained men two different ways to do bench presses — one with slow reps and one with faster reps — but made sure both took the same total time per set. After 10 weeks, both groups got just as strong and built just as much muscle, so the speed of the reps didn’t matter as long as the total time under tension was the same.