Izvorni znanstveni članak
https://doi.org/10.69589/hsv.41.1.5
Magnesium delays rer elevation and improves tolerance to high-intensity running
Marina Banović
; Sveti Duh University Hospital, Zagreb, Croatia
Robert Bobinec
; University of Zagreb Faculty of Kinesiology
Vlatko Vučetić
; University of Zagreb Faculty of Kinesiology
Sažetak
The respiratory exchange ratio (RER) provides a sensitive marker of metabolic stress during highintensity exercise. Delayed RER elevation may reflect improved tolerance to rising glycolytic demand and acid– base disturbance. This study examined whether acute intravenous magnesium injection influences the timing of RER transitions during running at vVO₂max and whether these changes correspond with alterations in time to exhaustion in Tlim test. Sixteen trained runners completed two TLim tests at vVO₂max in a randomized, single-blind crossover design. Before each test, participants received either intravenous magnesium (1 g) or placebo. Breath-by-breath gas exchange was continuously measured. Primary outcomes were times to reach individual maximal RER. Secondary outcomes included time to exhaustion in TLim test, RVO₂max, HRmax. Magnesium delayed the rise in RER, with athletes reaching individual maximal RER approximately 19.75 s later than in the placebo condition (p < 0.001). This was accompanied by a significant increase in time in Tlim test (222.15 ± 45.11 s vs. 207.63 ± 38.69 s; p < 0.001). RVO₂ max and HRmax were not different between conditions (p= 0.57 and p = 0.06). Ventilatory measures showed small, non-significant differences. Intravenous magnesium injection delays the onset of elevated RER during high-intensity exercise, indicating reduced metabolic disturbance. This effect occurs alongside an increase in time to exhaustion in TLim test but without changes in rVO₂max or heart rate, suggesting a peripheral metabolic mechanism rather than altered cardiopulmonary function.
Ključne riječi
respiratory exchange ratio; RER kinetics; high-intensity exercise; vVO₂max; time to exhaustion; metabolic response
Hrčak ID:
348759
URI
Datum izdavanja:
30.6.2026.
Posjeta: 0 *