A high-intensity, intermittent exercise protocol and dynamic postural control in men and women.

CONTEXT Deficits in dynamic postural control predict lower limb injury. Differing fatiguing protocols negatively affect dynamic postural control. The effect of high-intensity, intermittent exercise on dynamic postural control has not been investigated. OBJECTIVE To investigate the effect of a high-intensity, intermittent exercise protocol (HIIP) on the dynamic postural control of men and women as measured by the Star Excursion Balance Test (SEBT). DESIGN Descriptive laboratory study. SETTING University gymnasium. PATIENTS OR OTHER PARTICIPANTS Twenty male (age = 20.83 ± 1.50 years, height = 179.24 ± 7.94 cm, mass = 77.67 ± 10.82 kg) and 20 female (age = 20.45 ± 1.34 years, height = 166.08 ± 5.83 cm, mass = 63.02 ± 6.67 kg) athletes. INTERVENTION(S) We recorded SEBT measurements at baseline, pre-HIIP, and post-HIIP. The HIIP consisted of 4 repetitions of 10-m forward sprinting with a 90° change of direction and then backward sprinting for 5 m, 2 repetitions of 2-legged jumping over 5 hurdles, 2 repetitions of high-knee side stepping over 5 hurdles, and 4 repetitions of lateral 5-m shuffles. Participants rested for 30 seconds before repeating the circuit until they reported a score of 18 on the Borg rating of perceived exertion scale. MAIN OUTCOME MEASURE(S) A mixed between- and within-subjects analysis of variance was conducted to assess time (pre-HIIP, post-HIIP) × sex interaction effects. Subsequent investigations assessed the main effect of time and sex on normalized maximal SEBT scores. We used intraclass correlation coefficients to determine the test-retest reliability of the SEBT and paired-samples t tests to assess the HIIP effect on circuit times. RESULTS We found a time × sex effect (F(8,69) = 3.5; P range, <.001-.04; η(2) range, 0.057-0.219), with women less negatively affected. We also noted a main effect for time, with worse normalized maximal SEBT scores postfatigue (F(8,69) = 22.39; P < .001; η(2) range, 0.324-0.695), and for sex, as women scored better in 7 SEBT directions (F(8,69) = 0.84; P range, <.001-008; η(2) range, 0.088-0.381). The intraclass correlation coefficients demonstrated high (0.77-0.99) test-retest repeatability. Paired-samples t tests demonstrated increases in circuit time post-HIIP (P < .001). CONCLUSIONS The HIIP-induced fatigue negatively affected normalized maximal SEBT scores. Women had better scores than men and were affected less negatively by HIIP-induced fatigue.