scholarly journals Effect of Carbohydrate Content in a Pre-event Meal on Endurance Performance-Determining Factors: A Randomized Controlled Crossover-Trial

2021 ◽  
Vol 3 ◽  
Author(s):  
Mats Holst Aandahl ◽  
Dionne A. Noordhof ◽  
Arnt Erik Tjønna ◽  
Øyvind Sandbakk
Keyword(s):  
Endurance Performance ◽  
Peak Oxygen Uptake ◽  
Repeated Measure ◽  
Time To Exhaustion ◽  
Test Protocol ◽  
Exercise Tests ◽  
Significant Interaction Effect ◽  
Fasted State ◽  
Determining Factors ◽  
Blood Lactate Accumulation

The current study aimed to investigate the effect of the relative CHO content in a pre-event meal on time to exhaustion (TTE), peak oxygen uptake (V∙O2peak), the 2nd lactate threshold (LT2), onset of blood lactate accumulation (OBLA), and work economy (WE) and to compare responses between well-trained and recreationally trained individuals. Eleven well-trained and 10 recreationally trained men performed three trials in a randomized cross-over design, in which they performed exercise tests (1) after a high-CHO pre-event meal (3 g · kg−1), (2) a low-CHO pre-event meal (0.5 g · kg−1), or (3) in a fasted-state. The test protocol consisted of five submaximal 5-min constant-velocity bouts of increasing intensity and a graded exercise test (GXT) to measure TTE. A repeated measure ANOVA with a between-subjects factor (well-trained vs. recreational) was performed. A main effect of pre-event meal was found (p = 0.001), with TTE being 8.0% longer following the high-CHO meal compared to the fasted state (p = 0.009) and 7.2% longer compared to the low-CHO meal (p = 0.010). No significant effect of pre-event meal on V∙O2peak, LT2, OBLA, or WE (p ≥ 0.087) was found and no significant interaction effect between training status and pre-event CHO intake was found for TTE or any of the performance-determining variables (p ≥ 0.257). In conclusion, high-CHO content in the pre-event meal led to a longer TTE compared to a meal with a low-CHO content or exercising in a fasted state, both in well-trained and recreationally trained participants. However, the underlying physiological reason for the increased TTE is unclear, as no effect of pre-event meal on the main physiological performance-determining variables was found. Thus, pre-event CHO intake should be standardized when the goal is to assess endurance performance but seems to be of less importance when assessing the main performance-determining variables.

scholarly journals Evaluation of the repeatability and reliability of the cross-training specific Fight Gone Bad workout and its relation to aerobic fitness

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Krzysztof Durkalec-Michalski ◽  
Emilia E. Zawieja ◽  
Bogna E. Zawieja ◽  
Tomasz Podgórski
Keyword(s):  
Gas Exchange ◽  
Aerobic Fitness ◽  
Peak Oxygen Uptake ◽  
Aerobic Performance ◽  
Time To Exhaustion ◽  
Strongly Correlated ◽  
Exercise Tests ◽  
Bland Altman Method ◽  
Cross Training ◽  
Gas Exchange Threshold

AbstractCross-training is a high-intensity functional training (HIFT) with multiple workout modalities. Despite the increasing number of studies in HIFT, there is still no validated test to measure its specific performance. It would also be advisable to determine whether selected cross-training workouts can implement a stimulus corresponding to maximize aerobic work. For these reasons, the purpose of our study was to evaluate the repeatability and reliability of Fight Gone Bad (FGB) workout and to assess its relationship with aerobic fitness. Twenty-one cross-training participants (9 females) finished the study protocol which included three two-day measurement sessions separated by 10 days. During each session, participants had their body composition measured, and they performed two exercise tests. The first test was an incremental cycling test to measure aerobic fitness, and the second was a cross-training specific FGB workout performed the next day. Reliability and repeatability were calculated from the three measurements. The total FGB Score (FGBTOTAL) showed excellent reliability (ICC 0.9, SEM 6%). Moreover, FGBTOTAL was strongly correlated with aerobic fitness (i.e., time to exhaustion (Texh, R2 = 0.72), maximal workload (Wmax, R2 = 0.69), time to gas exchange threshold (TGET, R2 = 0.68), and peak oxygen uptake (VO2peak, R2 = 0.59). We also found that agreement between standardized FGB and standardized aerobic performance indices such as Texh, VO2peak, Wmax, maximum heart rate, TGET, and workload at gas exchange threshold was high by the Bland–Altman method. In conclusion, FGB is a reliable test that can be used in order to measure changes in cross-training performance caused by an intervention. Moreover, FGB is strongly correlated to aerobic fitness.

Whole-Body Cryotherapy’s Enhancement of Acute Recovery of Running Performance in Well-Trained Athletes

2015 ◽  
Vol 10 (5) ◽  
pp. 605-612 ◽  
Author(s):  
Malte Krüger ◽  
Markus de Mareés ◽  
Karl-Heinrich Dittmar ◽  
Billy Sperlich ◽  
Joachim Mester
Keyword(s):  
High Intensity ◽  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Vastus Lateralis ◽  
Recovery Period ◽  
Endurance Performance ◽  
Rating Of Perceived Exertion ◽  
Whole Body ◽  
Time To Exhaustion ◽  
Test Protocol

Purpose:To examine the effects of a whole-body cryotherapy (WBC) protocol (3 min at –110°C) on acute recovery and key variables of endurance performance during high-intensity intermittent exercise in a thermoneutral environment.Methods:Eleven endurance athletes were tested twice in a randomized crossover design in which 5 × 5 min of high-intensity running (HIR) were followed by 1 h of passive rest at ~22°C, including either 3 min of whole-body exposure to –110°C (WBC) or a placebo intervention of 3 min walking (PBO). A ramp-test protocol was performed before HIR (R1) and after the 1-h recovery period (R2). Time to exhaustion (tlim) was measured along with alterations in oxygen content of the vastus lateralis (TSI), oxygen consumption (VO2), capillary blood lactate, heart rate (HR), and rating of perceived exertion (RPE) during submaximal and maximal running.Results:The difference in tlim between R1 and R2 was lower in WBC than in PBO (P < .05, effect size d = 1.13). During R2, TSI was higher in WBC during submaximal and maximal running (P < .01, d = 0.68−1.01). In addition, VO2, HR, and RPE were lower at submaximal level of R2 after WBC than in PBO (P = .04 to <.01, d = 0.23−0.83).Conclusion:WBC improves acute recovery during high-intensity intermittent exercise in thermoneutral conditions. The improvements might be induced by enhanced oxygenation of the working muscles, as well as a reduction in cardiovascular strain and increased work economy at submaximal intensities.

scholarly journals Physiological responses and cycle characteristics during double-poling versus diagonal-stride roller-skiing in junior cross-country skiers

2021 ◽  
Author(s):  
Erik P. Andersson ◽  
Irina Hämberg ◽  
Paulo Cesar Do Nascimento Salvador ◽  
Kerry McGawley
Keyword(s):  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Oxygen Uptake ◽  
Submaximal Exercise ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Double Poling ◽  
Cross Country

Abstract Purpose This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. Methods Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2 yr.) completed two treadmill roller-skiing tests in a randomized order using either DP or DS. The exercise protocols were identical and included a 5 min warm-up, 4 × 5 min submaximal stages, and an incremental test to exhaustion, all performed at a 5° incline. Results No significant three-way interactions were observed between sex, submaximal exercise intensity, and sub-technique. For the pooled sample, higher values were observed for DP versus DS during submaximal exercise for the mean oxygen uptake kinetics response time (33%), energy cost (18%), heart rate (HR) (9%), blood lactate concentration (5.1 versus 2.1 mmol·L−1), rating of perceived exertion (12%), and cycle rate (25%), while cycle length was lower (19%) (all P < 0.001). During the time-to-exhaustion (TTE) test, peak oxygen uptake ($$\dot{V}$$ V ˙ O2peak), peak HR, and peak oxygen pulse were 8%, 2%, and 6% lower, respectively, for DP than DS, with a 29% shorter TTE during DP (pooled data, all P < 0.001). Conclusion In well-trained junior XC skiers, DP was found to exert a greater physiological load than DS during uphill XC roller-skiing at submaximal intensities. During the TTE test, both female and male athletes were able to ski for longer and reached markedly higher $$\dot{V}$$ V ˙ O2peak values when using DS compared to DP.

Electrically-induced quadriceps fatigue in the contralateral leg impairs ipsilateral knee extensors performance

2021 ◽  
Author(s):  
Fabio Giuseppe Laginestra ◽  
Markus Amann ◽  
Emine Kirmizi ◽  
Gaia Giuriato ◽  
Chiara Barbi ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Central Fatigue ◽  
Endurance Performance ◽  
Voluntary Exercise ◽  
Peripheral Fatigue ◽  
Knee Extensors ◽  
Motor Drive ◽  
Time To Exhaustion ◽  
Crossover Effect ◽  
The Impact

Muscle fatigue induced by voluntary exercise, which requires central motor drive, causes central fatigue that impairs endurance performance of a different, non-fatigued muscle. This study investigated the impact of quadriceps fatigue induced by electrically-induced (no central motor drive) contractions on single-leg knee-extension (KE) performance of the subsequently exercising ipsilateral quadriceps. On two separate occasions, eight males completed constant-load (85% of maximal power-output) KE exercise to exhaustion. In a counterbalanced manner, subjects performed the KE exercise with no pre-existing quadriceps fatigue in the contralateral leg on one day (No-PreF), while on the other day, the same KE exercise was repeated following electrically-induced quadriceps fatigue in the contralateral leg (PreF). Quadriceps fatigue was assessed by evaluating pre- to post-exercise changes in potentiated twitch force (ΔQtw,pot; peripheral-fatigue), and voluntary muscle activation (ΔVA; central-fatigue). As reflected by the 57±11% reduction in electrically-evoked pulse force, the electrically-induced fatigue protocol caused significant knee-extensors fatigue. KE endurance time to exhaustion was shorter during PreF compared to No-PreF (4.6±1.2 vs 7.7±2.4 min; p<0.01). While ΔQtw,pot was significantly larger in No-PreF compared to PreF (-60% vs -52%, p<0.05), ΔVA was greater in PreF (-14% vs -10%, p<0.05). Taken together, electrically-induced quadriceps fatigue in the contralateral leg limits KE endurance performance and the development of peripheral fatigue in the ipsilateral leg. These findings support the hypothesis that the crossover-effect of central fatigue is mainly mediated by group III/IV muscle afferent feedback and suggest that impairments associated with central motor drive may only play a minor role in this phenomenon.

scholarly journals To Focus or Not to Focus: Is Attention on the Core Components of Action Beneficial for Cycling Performance?

2015 ◽  
Vol 29 (2) ◽  
pp. 110-119 ◽  
Author(s):  
Maurizio Bertollo ◽  
Selenia di Fronso ◽  
Edson Filho ◽  
Vito Lamberti ◽  
Patrizio Ripari ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Attentional Focus ◽  
Task Type ◽  
Repeated Measure ◽  
Time To Exhaustion ◽  
Experimental Conditions ◽  
Core Components ◽  
Type 3

We conducted a counterbalanced repeated measure trial to investigate the effect of different internal and external associative strategies on endurance performance. Seventeen college-aged students were randomly assigned to three experimental conditions to test the notion that different attention-performance types (optimal Type 1, functional Type 2, and dysfunctional Type 3) would influence endurance time on a cycling task. Specifically, Type 1 represented an effortless and automatic, “flow-feeling” attentional mode. Type 2 referred to an associative focus directed at core components of the task. Type 3 represented an attentional focus directed at irrelevant components of the task. Participants completed three time-to-exhaustion-tests while reporting their perceived exertion and affective states (arousal and hedonic tone). Results revealed that Type 1 and Type 2 attentional strategies, compared with Type 3 strategy, exerted functional effects on performance, whereas a Type 3 strategy was linked to lower performance, and lower levels of arousal and pleasantness. Applied implications are discussed.

Cardiopulmonary fitness is related to disease severity in multiple sclerosis

2015 ◽  
Vol 22 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Martin Heine ◽  
Inez Wens ◽  
Martin Langeskov-Christensen ◽  
Olaf Verschuren ◽  
Bert O Eijnde ◽  
...  
Keyword(s):  
Disease Severity ◽  
Close Relation ◽  
Progressive Increase ◽  
Peak Oxygen Uptake ◽  
Multiple Regression Model ◽  
Exercise Tests ◽  
Cardiopulmonary Fitness ◽  
Disability Status ◽  
Related Quality ◽  
Health Related

Background: In persons with MS (pwMS), a lower cardiopulmonary fitness has been associated with a higher risk for secondary disorders, decreased functional capacity, symptom worsening and reduced health-related quality of life. Objective: To investigate the association between disease severity and cardiopulmonary fitness. Methods: Data from cardiopulmonary exercise tests, previously conducted in three different countries, were pooled. The association between disease severity (Expanded Disability Status Scale (EDSS)) and cardiopulmonary fitness (peak oxygen uptake (VO2peak)) was adjusted for age, sex and the country of origin. Results: The combined sample comprised 116 ambulant pwMS having a mean (± SD) EDSS score of 2.7 ± 1.3. There was a significant correlation ( r = -0.418, p < .01) between VO2peak and EDSS. A multiple regression model (R2 = 0.520, p < .01) was constructed to describe VO2peak (mL∙kg−1∙min−1); VO2peak = 36.622 − 5.433 (Sex (1=men)) – 0.124 (Age) − 2.082 (EDSS) + 2.737 (Belgium) + 8.674 (Denmark). Conclusion: There was a significant association between disease severity and cardiopulmonary fitness. The close relation between cardiopulmonary fitness and chronic conditions associated with physical inactivity, suggest a progressive increase in risk of secondary health conditions in pwMS

Threshold for muscle lactate accumulation during progressive exercise

1989 ◽  
Vol 66 (6) ◽  
pp. 2710-2716 ◽  
Author(s):  
J. Chwalbinska-Moneta ◽  
R. A. Robergs ◽  
D. L. Costill ◽  
W. J. Fink
Keyword(s):  
Blood Lactate ◽  
Bicycle Ergometer ◽  
Exercise Tests ◽  
Muscle Lactate ◽  
Lactate Accumulation ◽  
Ergometer Exercise ◽  
Progressive Exercise ◽  
Blood Lactate Accumulation ◽  
Highly Correlated ◽  
The Relationship

The purpose of this study was to investigate the relationship between muscle and blood lactate concentrations during progressive exercise. Seven endurance-trained male college students performed three incremental bicycle ergometer exercise tests. The first two tests (tests I and II) were identical and consisted of 3-min stage durations with 2-min rest intervals and increased by 50-W increments until exhaustion. During these tests, blood was sampled from a hyperemized earlobe for lactate and pH measurement (and from an antecubital vein during test I), and the exercise intensities corresponding to the lactate threshold (LT), individual anaerobic threshold (IAT), and onset of blood lactate accumulation (OBLA) were determined. The test III was performed at predetermined work loads (50 W below OBLA, at OBLA, and 50 W above OBLA), with the same stage and rest interval durations of tests I and II. Muscle biopsies for lactate and pH determination were taken at rest and immediately after the completion of the three exercise intensities. Blood samples were drawn simultaneously with each biopsy. Muscle lactate concentrations increased abruptly at exercise intensities greater than the “below-OBLA” stage [50.5% maximal O2 uptake (VO2 max)] and resembled a threshold. An increase in blood lactate and [H+] also occurred at the below-OBLA stage; however, no significant change in muscle [H+] was observed. Muscle lactate concentrations were highly correlated to blood lactate (r = 0.91), and muscle-to-blood lactate ratios at below-OBLA, at-OBLA, and above-OBLA stages were 0.74, 0.63, 0.96, and 0.95, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Consumption of açai (Euterpe oleraceaMart.) functional beverage reduces muscle stress and improves effort tolerance in elite athletes: a randomized controlled intervention study

2015 ◽  
Vol 40 (7) ◽  
pp. 725-733 ◽  
Author(s):  
Jacqueline Carvalho-Peixoto ◽  
Mirian Ribeiro Leite Moura ◽  
Felipe Amorim Cunha ◽  
Pablo Christiano B. Lollo ◽  
Walace David Monteiro ◽  
...  
Keyword(s):  
High Intensity ◽  
Perceived Exertion ◽  
Maximal Exercise ◽  
Metabolic Stress ◽  
Ergogenic Aid ◽  
Treadmill Running ◽  
Time To Exhaustion ◽  
Euterpe Oleracea ◽  
Exercise Tests ◽  
Cardiorespiratory Responses

The study analyzed the effect of an açai (Euterpe oleracea Mart.) functional beverage (AB) on muscle and oxidative stress markers, cardiorespiratory responses, perceived exertion, and time-to-exhaustion during maximal treadmill running. The beverage was developed as an ergogenic aid for athletes and contained 27.6 mg of anthocyanins per dose. Fourteen athletes performed 3 exercise tests: a ramp-incremental maximal exercise test and 2 maximal exercise bouts performed in 2 conditions (AB and without AB (control)) at 90% maximal oxygen uptake.Blood was collected at baseline and after maximal exercise in both conditions to determine biomarkers. AB increased time to exhaustion during short-term high-intensity exercise (mean difference: 69 s, 95% confidence interval = –296 s to 159 s, t = 2.2, p = 0.045), attenuating the metabolic stress induced by exercise (p < 0.05). AB also reduced perceived exertion and enhanced cardiorespiratory responses (p < 0.05). The AB may be a useful and practical ergogenic aid to enhance performance during high-intensity training.

Influence of endurance training on muscle [PCr] kinetics during high-intensity exercise

2007 ◽  
Vol 293 (1) ◽  
pp. R392-R401 ◽  
Author(s):  
Andrew M. Jones ◽  
Daryl P. Wilkerson ◽  
Nicolas J. Berger ◽  
Jonathan Fulford
Keyword(s):  
Endurance Training ◽  
High Intensity ◽  
Slow Component ◽  
Knee Extension ◽  
High Intensity Exercise ◽  
Whole Body ◽  
Time To Exhaustion ◽  
Exercise Tests ◽  
Before And After ◽  
Knee Extension Exercise

We hypothesized that a period of endurance training would result in a speeding of muscle phosphocreatine concentration ([PCr]) kinetics over the fundamental phase of the response and a reduction in the amplitude of the [PCr] slow component during high-intensity exercise. Six male subjects (age 26 ± 5 yr) completed 5 wk of single-legged knee-extension exercise training with the alternate leg serving as a control. Before and after the intervention period, the subjects completed incremental and high-intensity step exercise tests of 6-min duration with both legs separately inside the bore of a whole-body magnetic resonance spectrometer. The time-to-exhaustion during incremental exercise was not changed in the control leg [preintervention group (PRE): 19.4 ± 2.3 min vs. postintervention group (POST): 19.4 ± 1.9 min] but was significantly increased in the trained leg (PRE: 19.6 ± 1.6 min vs. POST: 22.0 ± 2.2 min; P < 0.05). During step exercise, there were no significant changes in the control leg, but end-exercise pH and [PCr] were higher after vs. before training. The time constant for the [PCr] kinetics over the fundamental exponential region of the response was not significantly altered in either the control leg (PRE: 40 ± 13 s vs. POST: 43 ± 10 s) or the trained leg (PRE: 38 ± 8 s vs. POST: 40 ± 12 s). However, the amplitude of the [PCr] slow component was significantly reduced in the trained leg (PRE: 15 ± 7 vs. POST: 7 ± 7% change in [PCr]; P < 0.05) with there being no change in the control leg (PRE: 13 ± 8 vs. POST: 12 ± 10% change in [PCr]). The attenuation of the [PCr] slow component might be mechanistically linked with enhanced exercise tolerance following endurance training.

Metabolic Profiles of the 30-15 Intermittent Fitness Test and the Corresponding Continuous Version in Team-Sport Athletes—Elucidating the Role of Inter-Effort Recovery

2020 ◽  
pp. 1-6
Author(s):  
Sebastian Kaufmann ◽  
Ralph Beneke ◽  
Richard Latzel ◽  
Hanna Pfister ◽  
Olaf Hoos
Keyword(s):  
Oxygen Uptake ◽  
State Level ◽  
Peak Oxygen Uptake ◽  
Metabolic Energy ◽  
Time To Exhaustion ◽  
Metabolic Profiles ◽  
Energy Contribution ◽  
Continuous Version ◽  
Fitness Test

Purpose: To elucidate the role of inter-effort recovery in shuttle running by comparing the metabolic profiles of the 30-15 Intermittent Fitness Test (30-15IFT) and the corresponding continuous version (30-15IFT-CONT). Methods: Sixteen state-level handball players (age = 23 [3] y, height = 185 [7] cm, weight = 85 [14] kg) completed the 30-15IFT and 30-15IFT-CONT, and speed at the last completed stage (in kilometers per hour) and time to exhaustion (in seconds) were assessed. Furthermore, oxygen uptake (in milliliters per kilogram per minute) and blood lactate were obtained preexercise, during exercise, and until 15 minutes postexercise. Metabolic energy (in kilojoules), metabolic power (in Watts per kilogram), and relative (in percentage) energy contribution of the aerobic (WAER, WAERint), anaerobic lactic (WBLC, WBLCint), and anaerobic alactic (WPCr, WPCrint) systems were calculated by PCr-La-O2 method for 30-15IFT-CONT and 30-15IFT. Results: No difference in peak oxygen uptake was found between 30-15IFT and 30-15IFT-CONT (60.6 [6.6] vs 60.5 [5.1] mL·kg−1·min−1, P = .165, d = 0.20), whereas speed at the last completed stage was higher in 30-15IFT (18.3 [1.4] vs 16.1 [1.0] km·h−1, P < .001, d = 1.17). Metabolic energy was also higher in 30-15IFT (1224.2 [269.6] vs 772.8 [63.1] kJ, P < .001, d = 5.60), and metabolic profiles differed substantially for aerobic (30-15IFT = 67.2 [5.2] vs 30-15IFT-CONT = 85.2% [2.5%], P < .001, d = −4.01), anaerobic lactic (30-15IFT = 4.4 [1.4] vs 30-15IFT-CONT = 6.2% [1.8%], P < .001, d = −1.04), and anaerobic alactic (30-15IFT = 28.4 [4.7] vs 30-15IFT-CONT = 8.6% [2.1%], P < .001, d = 5.43) components. Conclusions: Both 30-15IFT and 30-15IFT-CONT are mainly fueled by aerobic energy, but their metabolic profiles differ substantially in both aerobic and anaerobic alactic energy contribution. Due to the presence of inter-effort recovery, intermittent shuttle runs rely to a higher extent on anaerobic alactic energy and a fast, aerobic replenishment of PCr during the short breaks between shuttles.

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