REF-1681 · Ferraro-Farro et al., 2026 · International Journal of Sports Medicine, · Paper · PubMed

Adding sprint interval training to resistance training showed no significant difference from lifting alone in strength, jump or sprint gains (SMD −0.06 to 0.11) and raised VO2max more (SMD 0.78, p = 0.001), in a meta-analysis of 9 RCTs with 177 healthy adults; short sprints of 10 s or less went with larger jump gains (SMD 0.41) in a sensitivity analysis. Hypertrophy, confidence intervals and risk of bias are not in the abstract

Main caveat: From the abstract: nine trials with 177 people, so small trials; the authors' own limitations are not in the abstract.
moderate evidenceMeasured on non-athletes to trained athletesRead from the abstract only

Ferraro-Farro and colleagues asked whether the interference effect of concurrent training, the idea that endurance work blunts strength and power gains, still appears when the endurance component is sprint interval training.

They searched three databases for randomised controlled trials in healthy adults that compared sprint interval training plus resistance training with resistance training alone, with at least six supervised sessions over two weeks, and found nine trials with 177 participants.

Against lifting alone, the combined programme gave no significant difference in lower-body strength (SMD 0.01), upper-body strength (−0.06), jump performance (0.11) or sprint performance (−0.01), and it raised VO2max more (SMD 0.78, p = 0.001). In a sensitivity analysis, protocols with sprints of 10 s or less gave a larger jump gain than lifting alone (SMD 0.41, p = 0.025).

The authors conclude that sprint interval work can be added to a lifting programme to raise aerobic fitness without costing strength or power, and that short sprints may even help jumping. Hypertrophy was among the stated outcomes, but the abstract reports no result for it.

Participants

9 RCTs, 177 healthy adults aged 18 or over.
Sex split, age range, training status and sport: not in the abstract.

Protocol

Search: PubMed, Embase and SPORTDiscus, following PRISMA 2020; search dates not in the abstract.
Inclusion: RCTs in healthy adults (18 or over) comparing SIT-based concurrent training with resistance training alone; at least six supervised sessions over 2 weeks.
Outcomes: strength (lower and upper body), hypertrophy, VO2max, jump and sprint performance.
Analysis: pooled standardised mean differences; a sensitivity analysis by sprint length (≤10 s).
Not in the abstract: the SIT protocols (sprint length beyond the ≤10 s split, number of sprints, mode), session order and spacing, programme length, risk-of-bias tool and findings, confidence intervals, heterogeneity, registration.

Key Results

Outcome (SIT + resistance training vs resistance training alone)SMDp
Lower-body strength0.010.94 (not significant)
Upper-body strength−0.060.83 (not significant)
Jump performance0.110.11 (not significant)
Sprint performance−0.010.95 (not significant)
VO2max0.780.001
Jump performance, sprints ≤10 s (sensitivity analysis)0.410.025
Hypertrophy: named as an outcome; no result in the abstract.
Confidence intervals and heterogeneity: not in the abstract, so how small an interference effect the data can exclude is unknown.

Practical Application

Short, hard sprint intervals can be added to a lifting programme without a measurable cost to strength, jump or sprint gains, and they raised VO2max more than lifting alone (SMD 0.78) across 9 small RCTs in healthy adults. "No significant difference" here is not shown to be zero: the abstract gives no confidence intervals.
Inference, not tested here: if the add-on is sprints, shorter ones may suit power goals better. Sprints of 10 s or less went with a larger jump gain than lifting alone (SMD 0.41) in a sensitivity analysis; longer sprints are not reported separately.
This fits the base's framing of interference as narrow. SYNTH-21 names explosive strength as the quality concurrent training puts at risk (REF-330: SMD −0.28 for explosive strength); with sprint interval work as the endurance part this review found no jump or sprint cost.Inference, not tested here: when power matters and both must happen in the same week, sprint intervals are a lower-risk aerobic add-on than long continuous sessions; the comparison with continuous endurance work was not made in this review.
Inference, not tested here: for an endurance athlete the VO2max gain over lifting alone says little, since the comparison group did no endurance work; this review does not show that sprint intervals can replace the endurance training an endurance athlete already does.

Limitations

From the abstract: nine trials with 177 people, so small trials; the authors' own limitations are not in the abstract.
Not in the abstract: confidence intervals, heterogeneity, the risk-of-bias tool and its findings, registration, the participants' training status and sex, and the SIT protocols; the hypertrophy result is missing although hypertrophy was a stated outcome.
The comparison is SIT added to lifting against lifting alone, so the extra training volume and the VO2max gain go together; the review does not compare SIT with continuous endurance work as the add-on.
The short-sprint jump result comes from a sensitivity analysis, a split between groups of studies, not a randomised comparison of sprint lengths.
Written from the abstract and the PubMed record; full text not read.
How this entry was checked and changed
Why this level

a meta-analysis of RCTs, the rubric's A design, capped because the risk of bias is not reported: risk of bias not read (abstract only); the trials are small (177 people across 9, about 20 per trial by our arithmetic) and no interval or heterogeneity is given