Improved Oxygen Uptake Efficiency Parameters Are Not Correlated with VO2peak or Running Economy and Are Not Affected by Omega-3 Fatty Acid Supplementation in Endurance Runners

Abstract

Peak oxygen uptake (VO2peak) is one of the most reliable parameters of exercise capacity; however, maximum effort is required to achieve this. Therefore, alternative, and repeatable submaximal parameters, such as running economy (RE), are needed. Thus, we evaluated the suitability of oxygen uptake efficiency (OUE), oxygen uptake efficiency plateau (OUEP) and oxygen uptake efficiency at the ventilatory anaerobic threshold (OUE@VAT) as alternatives for VO2peak and RE. Moreover, we evaluated how these parameters are affected by endurance training and supplementation with omega-3 fatty acids. A total of 26 amateur male runners completed a 12-week endurance program combined with omega-3 fatty acid supplementation or medium-chain triglycerides as a placebo. Before and after the intervention, the participants were subjected to a treadmill test to determine VO2peak, RE, OUE, OUEP and OUE@VAT. Blood was collected at the same timepoints to determine eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes. OUE correlated moderately or weakly with VO2peak (R2 = 0.338, p = 0.002) and (R2 = 0.226, p = 0.014) before and after the intervention, respectively. There was a weak or no correlation between OUEP, OUE@VAT, VO2peak and RE despite steeper OUE, increased OUEP and OUE@VAT values in all participants. OUE parameters cannot be treated as alternative parameters for VO2peak or RE and did not show changes following supplementation with omega-3 fatty acids in male amateur endurance runners.

Cardiorespiratory optimal point as a submaximal evaluation tool in endurance athletes: An exploratory study

“…Nevertheless, OUEP does not accurately predicts VO2max in non-athletes ( Sheridan et al, 2021 ). Likewise, a recent study reported no correlation between OUEP and VO2max in runners even after an increase in OUE ( Jost et al, 2022 ). Despite the previously mentioned absence of correlation between OUEP, OUE at anaerobic threshold (or other values through VE/VO2 signal) with performance variables, such as VO2max, physiologically VO2 as well as VE both are influenced by cardiorespiratory and peripheral variables ( Sun et al, 2012a ; Sun et al, 2012b ) Therefore, we used PCA to show how COP, a simplified index to obtained from the lowest VE/VO2 ratio in 60 s, influences metabolic and cardiorespiratory variables at VO2max and VT2 in the next section.…”

Fish Oil Supplementation Improves the Repeated-Bout Effect and Redox Balance in 20–30-Year-Old Men Submitted to Strength Training

“…The main anti-inflammatory n-3 PUFAs comprise eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have been demonstrated to reduce plasma lipids [ 3 , 29 , 30 ], oxidative stress conditions [ 31 , 32 ], insulin sensitivity [ 31 , 33 , 34 ], and inflammation [ 33 , 35 ]. Similar to regular and moderate aerobic exercise, n-3 PUFAs reduce fat mass [ 36 , 37 ] and cardiovascular risks [ 38 , 39 ], but they do not raise physical capabilities [ 40 ] or performance [ 41 , 42 ]. Interestingly, when young endurance athletes are supplemented with highly purified n-3 PUFAs (2.1 g DHA + 240 mg EPA per day for 10 wks), they present reduced muscle damage (plasma CK and LDH activities), inflammatory markers (plasma IL-6 and IL-1β), and muscle soreness after an eccentric-induced muscle damage exercise session [ 43 ].…”