Core training reliably improves core strength and endurance tests, but its transfer to swimming, cycling or running performance is small and inconsistent
Interpretation
The core-test effect is consistent: Reed et al. 2012 (24 studies) and Bustos Carvajal and Arias Coronel 2025 (7 trials, mostly male team-sport athletes) report gains in trunk strength, core endurance and balance, and small trials (Stanton 2004, n=18; Hung 2019, n=21; Weston 2015, n=20) improved core tests. Performance transfer is weak and mixed: Reed concluded benefits are marginal; Stanton found no running economy change; Hung found lower VO2 at one treadmill stage; Sato and Mokha 2009 (20 completers) found faster 5000 m times with improvement in controls too; Weston found a 2.0% faster 50 m sprint in junior swimmers. Abt 2007 (15 cyclists) shows core fatigue alters leg mechanics but tested no training. No trials in triathletes or long-course events.
Practical implication
Keep core work short (around 10 minutes, two or three times a week) as a supplement to heavy lower-body lifting rather than a replacement for it or for swim, bike and run sessions. Evidence is from small, mostly male, short-event samples.
Sources
7 sources, independently verified.
Most studies combined core training with other exercise; gains often appeared in general strength measures (e.g. squat load, vertical jump). Not all studies improved core strength or stability; studies targeting the core as the primary aim had mixed results. Authors concluded targeted core stability training provides marginal benefits to athletic performance, with conflicting findings and no standard outcome measures or protocols. Abstract read on SPONET; metadata on OpenAlex.
Core training improved trunk extensor strength, core endurance, dynamic balance and sprint speed; trunk flexor strength, jump height and agility were inconclusive. Mean PEDro score 5, common lack of blinding. Noted that in the included runner trial (Sato and Mokha 2009) the control group also improved significantly.
Swiss ball training twice a week for 6 weeks improved core stability but did not change abdominal or back EMG, treadmill VO2max, running economy or running posture. Authors concluded it may improve core stability without improving performance.
6 weeks of core strength training produced faster 5000 m times than control (significant interaction) but no change in ground reaction forces or lower-limb stability (Star Excursion Balance Test). Size of improvement not reported in the abstract; small sample with uneven drop-out.
Three extra core sessions per week for 8 weeks: only the core group improved balance (SOT 78.8 to 85.3) and plank endurance (193.5 to 241.5 s); heart rate was lower in the first three treadmill stages and VO2 at stage 4 fell from 52.4 to 50.0 ml/kg/min. Reported as within-group changes; non-endurance-specialist young men.
After a core-fatiguing workout, treadmill cycling to exhaustion showed greater frontal-plane knee motion (15.1 to 23.3°), sagittal knee motion (69.9 to 79.3°) and sagittal ankle motion (29.0 to 43.0°), with no change in pedal forces. Mechanistic study; no training intervention or performance outcome.
12 weeks of isolated core training 3 times a week added to pool training improved 50 m front crawl time by 2.0% vs control (90% CI −3.8 to −0.2%), prone bridge time by 9.0% and a straight-arm pull-down test by 23.1%. Sprint distance in young pool swimmers; not randomised at the individual level.