REF-1494 · Muñoz-Martínez et al., 2017 · Sports Medicine · Paper · PubMed

Can circuits build both VO2max and bench strength?

Against controls in healthy adults, yes by 8 + 8 studies; the abstract gives no effect sizes. Bench press only; not compared with separate strength or endurance work.

Main caveat: Abstract only. Direction without numbers; it cannot be used for a size.
moderate evidenceMeasured on non-athletes to trained athletes

The authors searched PubMed, Web of Science and Cochrane from January to June 2016 for studies of resistance circuit-based training in healthy adults, with VO2max by gas analyser and/or bench press 1RM. Eight articles were analysed for VO2max (118 adults performing circuits), and eight for bench 1RM (237 adults).

Both rose significantly after circuits and differed from controls. The authors give dosing for large effects: for VO2max about 14-30 sessions over about 6-12 weeks, each at least 20-30 min at about 60-90% 1RM; for bench about 30-60% 1RM and at least 22.5-60 min. They add that lower baseline fitness may explain the lighter loads with better strength gains.

Our reading: direction is reasonable for general fitness but the size is unknown from the abstract. It answers whether circuits beat a control group (the abstract does not say what controls did), not whether they beat separate strength and endurance sessions; so it supports circuits as a general fitness option, not as a substitute in an athlete's plan.

Protocol

Search: PubMed, Web of Science, Cochrane; January to June 2016.
Inclusion: healthy adults 18 to 65 years; meets resistance circuit-based training characteristics; VO2max with a gas analyser and/or 1RM bench press.
Studies and participants: VO2max: 100 articles found, 8 analysed, n = 118 who did the circuits. Bench 1RM: 308 articles found, 8 analysed, n = 237 who did the circuits.
Comparison: before vs after, and circuit vs control groups. The abstract does not say whether controls did nothing, or compare circuits with any other training.
Not given in the abstract: effect sizes, CIs, heterogeneity, quality assessment, sex, training status, weeks of the strength trials, how the dose figures were derived.
Funding and interests: not available from the abstract.

Key Results

OutcomeStudies; n in circuit groupsResult in the abstractPooled ES (95% CI)
VO2max8; 118Significant rise; significant difference vs controlNot given in the abstract
Bench press 1RM8; 237Significant rise; significant difference vs controlNot given in the abstract
Dose for "large effects" (authors' recommendation; derivation not in the abstract)SessionsWeeksSession lengthIntensity
VO2max~14-30~6-12at least ~20-30 min~60-90% 1RM
Bench press 1RMNot givenNot givenat least ~22.5-60 min~30-60% 1RM
Lower-body strength was not an outcome. Upper-body 1RM only.

Mechanisms

Authors' interpretation: effect appears to vary with population and training characteristics; a lower baseline fitness may explain the lighter loads in the studies with greater strength gains.
Not reported in the abstract: any measured mechanism.
Inference: the odd-looking lighter load for the strength outcome is probably novices responding to anything; the authors offer that explanation, and it was not tested head to head.

Practical Application

Can circuits build both VO2max and bench strength? Against controls in healthy adults, yes by 8 + 8 studies; the abstract gives no effect sizes. Bench press only; not compared with separate strength or endurance work.
What it gives the guide: a general-fitness option for a person short of time, with the honest limit that the effect is measured against a control, on the bench press.
Dose: the 14-30 sessions, 6-12 weeks and % 1RM figures are the authors' recommendation, derivation not in the abstract; the app has no %1RM and the guide should not import them as a rule.
Does not test: progression in a circuit (rounds, load, time), lower-body strength, an endurance athlete, or HYROX. As far as the abstract goes, no rule from here.

Limitations

Abstract only. Direction without numbers; it cannot be used for a size.
Comparator. Control only, as the abstract describes; it does not show superiority over any other training.
Dose thresholds. Their derivation is not in the abstract, which reports no head-to-head test, and the authors themselves name baseline fitness as a possible explanation for the lighter loads on the strength result.
Upper body only. A bench press in a mixed-adult sample is a weak guide to a lifter's main goal.
Old search, closed in June 2016.
Interests. Not available from the abstract.
How this entry was checked and changed
Why this level

its design alone would reach A- (a meta-analysis of small studies), held a step lower because the abstract carries direction only: no pooled effect size, CI, heterogeneity or quality, and the abstract does not say how the dose figures were derived. Read from the abstract only; OpenAlex lists a repository copy (RIUCAM), which returned a server error, and we did not retry