Title Post-activation potentiation and fatigue in quadriceps femoral muscle after a 5 s maximal voluntary isometric contraction /
Translation of Title Keturgalvio šlaunies raumens postaktyvacinė potenciacija ir nuovargis atlikus 5 s trukmės maksimalaus intensyvumo izometrinį krūvį.
Another Title Keturgalvio šlaunies raumens postaktyvacinė potenciacija ir nuovargis atlikus nenutrūkstamą maksimalaus ir submaksimalaus intensyvumo krūvį.
Authors Masiulis, Nerijus ; Skurvydas, Albertas ; Kamandulis, Sigitas ; Sniečkus, Audrius ; Brazaitis, Marius ; Daniusevičiūtė, Laura ; Klizienė, Irina
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Is Part of Ugdymas. Kūno kultūra. Sportas = Education. Physical training. Sport / Lietuvos kūno kultūros akademija.. Kaunas : Lietuvos kūno kultūros akademija. 2008, nr. 1(68), p. 55-60.. ISSN 1392-5644
Keywords [eng] Isometric exercise ; Electrical stimulation ; Low-frequency fatigue ; Recovery
Abstract [eng] Following an acute physical exercise, both post-activation potentiation and fatigue of the neuromuscular apparatus may occur. The voluntary recruitment of motor units occurs with frequencies that elicit incompletely fused tetanic contractions and these frequencies are most susceptible for post-activation potentiation as well as low-frequency fatigue. Therefore, the goal of the present study was to investigate which of the processes post-activation potentiation or low-frequency fatigue will be prevalent after 5 s maximal voluntary contraction (MVC). Eight healthy untrained men (age 24—35 years, mass 81.2 ± 5.1 kg) performed maximal sustained isometric knee extension for 5 s at a knee angle of 90 degrees. The contractile properties of quadriceps muscle evoked by electrical stimulation at 1, 7, 10, 15, 20, 50 Hz and 100 Hz, were recorded before and immediately after the exercise and 3, 5, and 10 min following the exercise. The rest interval between muscle electrical stimulation was 3 s. A signifi cant raise of force evoked by 1—15 Hz stimulation was observed immediately after the 5 s MVC exercise (p < 0.01). Later in recovery (at 10 min) the contraction force at 15 Hz and 20 Hz signifi cantly decreased (p < 0.05). Tetanic force at 50 Hz and 100 Hz demonstrated a signifi cant decrease immediately after the exercise and remained depressed up to 3 min (p < 0.01). The ratio of 20 / 50 Hz recorded immediately after the 5 s MVC increased signifi cantly (p < 0.05), however 10 min after the exercise there was a signifi cant decrease compared to its initial level (p < 0.05). The simultaneous occurrence of post-activation potentiation at low stimulation frequencies and suppressed forces at high stimulation frequencies suggests that potentiation and fatigue mechanisms were acting concurrently. Moreover, when post-activation potentiation is lost (in 10 min after the 5 s MVC exercise), [...].
Published Kaunas : Lietuvos kūno kultūros akademija
Type Journal article
Language English
Publication date 2008