The Relationship between Resistance Exercise Performance and Ventilatory Efficiency after Beetroot Juice Intake in Well-Trained Athletes

Abstract

The assessment of ventilatory efficiency is critical to understanding the matching of ventilation (VE) and perfusion in the lungs during exercise. This study aimed to establish a causal physiological relationship between ventilatory efficiency and resistance exercise performance after beetroot juice (BJ) intake. Eleven well-trained males performed a resistance exercise test after drinking 140 mL of BJ (~12.8 mmol NO3−) or a placebo (PL). Ventilatory efficiency was assessed by the VE•VCO2−1 slope, the oxygen uptake efficiency slope and the partial pressure of end-tidal carbon dioxide (PetCO2). The two experimental conditions were controlled using a randomized, double-blind crossover design. The resistance exercise test involved repeating the same routine twice, which consisted of wall ball shots plus a full squat (FS) with a 3 min rest or without a rest between the two exercises. A higher weight lifted was detected in the FS exercise after BJ intake compared with the PL during the first routine (p = 0.004). BJ improved the VE•VCO2−1 slope and the PetCO2 during the FS exercise in the first routine and at rest (p < 0.05). BJ intake improved the VE•VCO2−1 slope and the PetCO2 coinciding with the resistance exercise performance. The ergogenic effect of BJ could be induced under aerobic conditions at rest.

Similar Slow Component of Oxygen Uptake and Ventilatory Efficiency between an Aerobic Dance Session on an Air Dissipation Platform and a Constant-Load Treadmill Test in Healthy Women

“…The increased anaerobic environment produced by the increased blood lactate concentration in the AD session on an ADP would be expected to induce an increase in the VE·VCO 2 −1 slope [ 18 ]. The increase in exercise intensity induces an increase in the blood lactate levels, CO 2 levels , and the number of hydrogen ions [H + ].…”

“…In theory, the ventilatory efficiency would decrease as a result of the increasing ventilation required to eliminate the CO 2 produced in order to maintain pH homeostasis, causing a mismatch in the ventilation–perfusion relationship. However, no changes were noted in terms of ventilatory efficiency between both exercise modalities; thus, this mismatch in the ventilation–perfusion relationship did not occur, which is typical as the exercise intensity increases [ 18 ]. This confirms that the exercise intensity in both modalities was not high enough to cause this mismatch in the ventilation–perfusion ratio.…”

“…The VE/perfusion mismatch decreases the efficiency of pulmonary gas exchange, causing a state of hyperpnea and dyspnea that affects ventilatory performance [ 14 ]. The slope between the linear relationship of VE and carbon dioxide (VE·VCO 2 −1 slope) has been frequently used as a prognostic marker of ventilatory efficiency during an incremental test up to the anaerobic or ventilatory threshold [ 15 , 16 ], the ventilatory compensation point [ 11 ], in constant-load endurance and resistance exercise tests, and in resistance exercises of moderate and very high intensities [ 17 , 18 ].…”

“…As with the , exercise intensity also modulates the ventilatory efficiency response [ 18 ]. As exercise intensity increases, ventilation is increased to remove CO 2 and maintain homeostatic control of pH [ 12 ], arterial hypoxemia [ 19 ], and lactic acidosis [ 20 ], thereby conditioning ventilatory efficiency [ 18 ].…”

“…As with the , exercise intensity also modulates the ventilatory efficiency response [ 18 ]. As exercise intensity increases, ventilation is increased to remove CO 2 and maintain homeostatic control of pH [ 12 ], arterial hypoxemia [ 19 ], and lactic acidosis [ 20 ], thereby conditioning ventilatory efficiency [ 18 ]. At a constant-load intensity of the LT, similar to VT1, it has been proposed that both endurance exercises and resistance exercises maintain an efficient VE·VCO 2 −1 slope in a predominantly aerobic metabolism with a low blood lactate concentration (~2.7 mmol·L −1 ) [ 17 ].…”