Fig. 1.

HIIT exercise induces extensive RyR1 fragmentation in recreationally active subjects. (A) Representative Western blot reveals decreased expression of full-sized RyR1 (red arrow) 24 h after exercise, which was accompanied by the appearance of fragments of ∼375, 80, and 60 kDa (indicated by black arrows). (B) Mean relative distribution of native RyR1 and its fragments from four subjects; the total intensity of all four analyzed bands was set to 100% at each time point in each subject. (C) Representative Western blots and mean data of DHPR, SERCA2, CSQ1, DMD, and actin expression ∼10 min (n = 11) and 24 h (n = 5) after exercise; relative expression before exercise was set to 100% in each subject. Data are expressed as mean ± SEM.