Anaerobic Capacity is Associated with Metabolic Contribution and Mechanical Output Measured During the Wingate Test.

The study aimed to investigate the relationship between anaerobic capacity, mechanical and anaerobic contribution during the 30-s Wingate Anaerobic Test (30sWAnT). After familiarization, fifteen, male recreational mountain biking practitioners underwent the following sequence of tests: 1) a graded exercise test to determine maximal oxygen uptake and associated intensity i V ˙ O 2 m a x ; 2 and 3) supramaximal exhaustive effort at 115% of iVO2max and 30sWAnT, performed randomly. The glycolytic and phosphagen pathways measured during the supramaximal effort were significantly correlated with peak power (r = 0.85; p < 0.01 and r = 0.57; p = 0.02, respectively), mean power (r = 0.78; p < 0.01 and r = 0.69; p < 0.01, respectively), and total work (r = 0.78; p < 0.01 and r = 0.69; p< 0.02, respectively) measured during the 30sWAnT. A significant correlation was also found between anaerobic capacity and peak power (r = 0.88; p < 0.01), mean power (r = 0.89; p < 0.01), and total work (r = 0.89; p < 0.01). Additionally, anaerobic capacity estimated during the supramaximal effort and the anaerobic contribution measured during the 30sWAnT were not different (p = 0.44) and presented significant good reliability and association (ICC = 0.84; p = 0.001) and good agreement, evidenced by the mean of differences and 95% limits of agreement near to zero (mean bias = 0.11). The results suggest that glycolytic and phosphagen capacity were associated with mechanical performance in the 30sWAnT. In addition, anaerobic contribution during the 30sWAnT seems to be valid for estimating anaerobic capacity in recreational mountain bike cyclists, as well as to estimate the glycolytic and phosphagen contributions.

Correction: Anaerobic capacity estimated by the sum of both oxygen equivalents from the glycolytic and phosphagen pathways is dependent on exercise mode: Running versus cycling.

[This corrects the article DOI: 10.1371/journal.pone.0203796.].

Anaerobic capacity estimated by the sum of both oxygen equivalents from the glycolytic and phosphagen pathways is dependent on exercise mode: Running versus cycling.

The purpose of this study was to verify whether the exercise modality (i.e., running and cycling) alters the magnitude of "anaerobic" capacity estimated by a single supramaximal effort (AC[La]+EPOCfast). Fourteen healthy men (age: 26±9 years) underwent a maximum incremental test and a supramaximal effort to exhaustion at 115% of the intensity associated with maximal oxygen uptake to determine the AC[La]+EPOCfast (i.e., the sum of both oxygen equivalents from the glycolytic and phosphagen pathways), performed on both a treadmill and cycle ergometer. The maximal oxygen uptake during running was higher (p = 0.001; large effect size) vs. cycling (49.2±3.8 mL·kg-1·min-1 vs. 44.7±5.7 mL·kg-1·min-1, respectively). Contrarily, the oxygen equivalent from the glycolytic metabolism was not different between exercise modalities (p = 0.133; small effect size; running = 2.27±0.51 L and cycling = 2.33±0.49 L). Furthermore, the "anaerobic" capacity was likely meaningfully (3.9±0.6 L and 54.1±6.0 mL·kg-1) and very likely meaningfully greater in running than cycling (3.6±0.7 L and 49.2±6.1 mL·kg). Additionally, the contribution of the phosphagen metabolism was higher (p = 0.001; large effect size) for running compared to cycling (1.6±0.3 L vs.1.3±0.3 L respectively). Therefore, the "anaerobic" capacity estimated by the sum of both oxygen equivalents from the glycolytic and phosphagen pathways during a supramaximal effort is influenced by exercise modality and is able to identify the difference in phosphagen metabolic contribution, based on the methodological conditions of this study.

Anaerobic Capacityestimated in A Single Supramaximal Test in Cycling: Validity and Reliability Analysis.

The aim was to verify the validity (i.e., study A) and reliability (i.e., study B) of the alternative maximal accumulated oxygen deficit determined using onlya supramaximal effort (MAODALT)to estimate anaerobic capacity [i.e., estimated by the gold standard maximal accumulated oxygen deficit method (MAOD)] during cycling. In study A, the effects of supramaximal intensities on MAODALT and the comparison with the MAOD were investigated in fourteen active subjects (26 ± 6 years). In study B, the test-retest reliability was investigated, where fourteen male amateur cyclists (29 ± 5 years) performed the MAODALT twice at 115% of the intensity associated to maximal oxygen uptake (). MAODALT determined at 130 and 150% of was lower than MAOD (p ≤ 0.048), but no differences between MAODALT determined at 100, 105, 110, 115, 120 and 140% of (3.58 ± 0.53L; 3.58 ± 0.59L; 3.53 ± 0.52L; 3.48 ± 0.72L; 3.52 ± 0.61L and 3.46 ± 0.69L, respectively) with MAOD (3.99 ± 0.64L). The MAODALT determined from the intensities between 110 and 120% of presented the better agreement and concordance with MAOD. In the test-retest, the MAODALT was not different (p > 0.05), showed high reproducibility when expressed in absolute values (ICC = 0.96, p < 0.01), and a good level of agreement in the Bland-Altman plot analysis (mean differences ± CI95%:-0.16 ± 0.53L). Thus, the MAODALT seems to be valid and reliable to assess anaerobic capacity in cycling.

Relationship between anaerobic capacity estimated using a single effort and 30-s tethered running outcomes.

The purpose of the current study was to investigate the relationship between alternative anaerobic capacity method (MAODALT) and a 30-s all-out tethered running test. Fourteen male recreational endurance runners underwent a graded exercise test, a supramaximal exhaustive effort and a 30-s all-out test on different days, interspaced by 48h. After verification of data normality (Shapiro-Wilk test), the Pearson's correlation test was used to verify the association between the anaerobic estimates from the MAODALT and the 30-s all-out tethered running outputs. Absolute MAODALT was correlated with mean power (r = 0.58; P = 0.03), total work (r = 0.57; P = 0.03), and mean force (r = 0.79; P = 0.001). In addition, energy from the glycolytic pathway (E[La-]) was correlated with mean power (r = 0.58; P = 0.03). Significant correlations were also found at each 5s interval between absolute MAODALT and force values (r between 0.75 and 0.84), and between force values and E[La-] (r between 0.73 to 0.80). In conclusion, the associations between absolute MAODALT and the mechanical outputs from the 30-s all-out tethered running test evidenced the importance of the anaerobic capacity for maintaining force during the course of time in short efforts.

Beta-Alanine Supplementation Improves Throwing Velocities in Repeated Sprint Ability and 200-m Swimming Performance in Young Water Polo Players.

The purpose of this study was to investigate the effects of beta-alanine supplementation on specific tests for water polo. Fifteen young water polo players (16 ± 2 years) underwent a 200-m swimming performance, repeated-sprint ability test (RSA) with free throw (shooting), and 30-s maximal tethered eggbeater kicks. Participants were randomly allocated into two groups (placebo × beta-alanine) and supplemented with 6.4g∙day-1of beta-alanine or a placebo for six weeks. The mean and total RSA times, the magnitude based inference analysis showed a likely beneficial effect for beta-alanine supplementation (both). The ball velocity measured in the throwing performance after each sprint in the RSA presented a very like beneficial inference in the beta-alanine group for mean (96.4%) and percentage decrement of ball velocity (92.5%, likely beneficial). Furthermore, the percentage change for mean ball velocity was different between groups (beta-alanine=+2.5% and placebo=-3.5%; p = .034). In the 30-s maximal tethered eggbeater kicks the placebo group presented decreased peak force, mean force, and fatigue index, while the beta-alanine group maintained performance in mean force (44.1%, possibly beneficial), only presenting decreases in peak force. The 200-m swimming performance showed a possibly beneficial effect (68.7%). Six weeks of beta-alanine supplementation was effective for improving ball velocity shooting in the RSA, maintaining performance in the 30-s test, and providing possibly beneficial effects in the 200-m swimming performance.

Acute LED irradiation does not change the anaerobic capacity and time to exhaustion during a high-intensity running effort: a double-blind, crossover, and placebo-controlled study : Effects of LED irradiation on anaerobic capacity and performance in running.

The purpose of this study was to investigate the acute effects of photobiomodulation therapy using cluster light-emitting diodes (LEDT; 104 diodes) (wavelength 660 and 850 nm; energy density 1.5 and 4.5 J/cm(2); energy 60 J at each point; total energy delivered 600 J) on alternative maximal accumulated oxygen deficit (MAODALT) and time to exhaustion, during a high-intensity running effort. Fifteen moderately active and healthy males (age 25.1 ± 4.4 years) underwent a graded exercise test and two supramaximal exhaustive efforts at 115 % of the intensity associated with maximal oxygen uptake performed after acute LEDT or placebo irradiation in a double-blind, crossover, and placebo-controlled study design. The MAODALT was assumed as the sum of both oxygen equivalents estimated from the glycolytic and phosphagen metabolism pathways during each supramaximal effort. For the statistical analysis, a paired t test was used to determine differences between the treatments. The significance level was assumed as 95 %. In addition, a qualitative analysis was used to determine the magnitude of differences between groups. No significant differences were found for the values of oxygen equivalents from each energetic metabolism (P ≥ 0.28), for MAODALT values between the LEDT and placebo conditions (P ≥ 0.27), or for time to exhaustion (P = 0.80), except for the respiratory exchange ratio (P = 0.01). The magnitude-based inference of effect size reported only a possibly negative effect of photobiomodulation on MAODALT when expressed in units relative to body mass and on the glycolysis pathway (26 %). In summary, LEDT after a high-intensity running effort did not alter the MAODALT, metabolic energy pathways, or high-intensity running performance.

Caffeine Improved Time to Exhaustion But Did Not Change Alternative Maximal Accumulated Oxygen Deficit Estimated During a Single Supramaximal Running Bout.

The aim of the current study was to investigate the effects of acute caffeine supplementation on anaerobic capacity determined by the alternative maximal accumulated oxygen deficit (MAODALT) in running effort. Eighteen recreational male runners [29 ± 7years; total body mass 72.1 ± 5.8 kg; height 176.0 ± 5.4cm; maximal oxygen uptake (VO2max) 55.8 ± 4.2 ml·kg-1 ·min-1] underwent a graded exercise test. Caffeine (6 mg·kg-1) or a placebo were administered 1 hr before the supramaximal effort at 115% of the intensity associated with VO2max in a double-blind, randomized cross-over study, for MAODALT assessment. The time to exhaustion under caffeine condition (130.2 ± 24.5s) was 11.3% higher (p = .01) than placebo condition (118.8 ± 24.9 s) and the qualitative inference for substantial changes showed a very likely positive effect (93%). The net participation of the oxidative phosphorylation pathway was significantly higher in the caffeine condition (p = .02) and showed a likely positive effect (90%) of 15.3% with caffeine supplementation. The time constant of abrupt decay of excess postexercise oxygen consumption (τ1) was significantly different between caffeine and placebo conditions (p = .03) and showed a likely negative effect (90%), decreasing -8.0% with caffeine supplementation. The oxygen equivalents estimated from the glycolytic and phosphagen metabolic pathways showed a possibly positive effect (68%) and possibly negative effect (78%) in the qualitative inference with caffeine ingestion, respectively. However, the MAODALT did not differ under the caffeine or placebo conditions (p = .68). Therefore, we can conclude that acute caffeine ingestion does not modify the MAODALT, reinforcing the robustness of this method. However, caffeine ingestion can alter the glycolytic and phosphagen metabolic pathway contributions to MAODALT.

Physiological responses at the lactate-minimum-intensity with and without prior high-intensity exercise.

This study examined the physiological responses during exercise-to-exhaustion at the lactate-minimum-intensity with and without prior high-intensity exercise. Eleven recreationally trained males performed a graded exercise test, a lactate minimum test and two constant-load tests at lactate-minimum-intensity until exhaustion, which were applied with or without prior hyperlactatemia induction (i.e., 30-s Wingate test). The physiological responses were significantly different (P < 0.05) between constant-load tests for pulmonary ventilation ([Formula: see text]), blood-lactate-concentration ([La(-)]), pH, bicarbonate concentration ([HCO3]) and partial pressure of carbon dioxide during the initial minutes. The comparisons within constant-load tests showed steady state behaviour for oxygen uptake and the respiratory exchange ratio, but heart rate and rating of perceived exertion increased significantly during both exercise conditions, while the [Formula: see text] increased only during constant-load effort. During effort performed after high-intensity exercise: [Formula: see text], [La(-)], pH and [HCO3] differed at the start of exercise compared to another condition but were similar at the end (P > 0.05). In conclusion, the constant-load exercises performed at lactate-minimum-intensity with or without prior high-intensity exercise did not lead to the steady state of all analysed parameters; however, variables such as [La(-)], pH and [HCO3] - altered at the beginning of effort performed after high-intensity exercise - were reestablished after approximately 30 min of exercise.

Sodium bicarbonate supplementation improved MAOD but is not correlated with 200- and 400-m running performances: a double-blind, crossover, and placebo-controlled study.

The aim of the study was to investigate the effects of acute supplementation of sodium bicarbonate (NaHCO3) on maximal accumulated oxygen deficit (MAOD) determined by a single supramaximal effort (MAODALT) in running and the correlation with 200- and 400-m running performances. Fifteen healthy men (age, 23 ± 4 years; maximal oxygen uptake, 50.6 ± 6.1 mL·kg(-1)·min(-1)) underwent a maximal incremental exercise test and 2 supramaximal efforts at 110% of the intensity associated with maximal oxygen uptake, which was carried out after ingesting either 0.3 g·kg(-1) body weight NaHCO3 or a placebo (dextrose) and completing 200- and 400-m performance tests. The study design was double-blind, crossover, and placebo-controlled. Significant differences were found between the NaHCO3 and placebo conditions for MAODALT (p = 0.01) and the qualitative inference for substantial changes showed a very likely positive effect (98%). The lactic anaerobic contribution in the NaHCO3 ingestion condition was significantly higher (p < 0.01) and showed a very likely positive effect (99% chance), similar to that verified for peak blood lactate concentration (p < 0.01). No difference was found for time until exhaustion (p = 0.19) or alactic anaerobic contribution (p = 0.81). No significant correlations were observed between MAODALT and 200- and 400-m running performance tests. Therefore, we can conclude that both MAODALT and the anaerobic lactic metabolism are modified after acute NaHCO3 ingestion, but it is not correlated with running performance.

Maximal Oxygen Uptake cannot be Determined in the Incremental Phase of The Lactate Minimum Test on a Cycle Ergometer.

The aim of this study was to investigate the maximal oxygen uptake (VO2MAX) determined using the incremental phase of the lactate minimum test (LM) on a cycle ergometer. Fifteen trained men were submitted to a graded exercise test (GXT) to evaluate the VO2MAX and LM. The total durations of the GXT and LM were 11.2±1.8 minutes (CI95%:10.2-12.3 minutes) and 25.3±3.2 minutes (CI95%:23.5-27.0), respectively. For the variables measured at exhaustion in both the GXT and LM, the oxygen uptake (54.6 ± 8.1 ml·kg(-1)·min(-1) vs 50.0 ± 7.7 ml·kg(-1)·min(-1)), carbon dioxide production (66.1 ± 7.5 ml·kg(-1)·min(-1) vs 50.4 ± 8.0 ml·kg(-1)·min(-1)), ventilation (153.9 ± 19.0 L·min(-1) vs 129.9 ± 22.9 L·min(-1)), respiratory exchange ratio (1.22 ± 0.10 vs1.01 ± 0.05), maximal power output achieved (331.6 ± 45.8 W vs 242.4 ± 41.0 W), heart rate (183.1 ± 6.9 bpm vs175.9 ± 10.6 bpm) and lactate (10.5 ± 2.3 mmol·L(-1) vs 6.6 ± 2.2 mmol·L(-1)) were statistically lower in the LM (p < 0.05). However, the values of rating of perceived exertion (17.6 ± 2.5 for GXT and 17.2 ± 2.3 for LM) did not differ (ES = 0.12 and CV = 7.8%). There was no good agreement between the values of the VO2MAX from the GXT and VO2PEAK from the LM, as evidenced in the Bland-Altman plot (4.7 ml·kg(-1)·min(-1) and 0.34 L·min(-1) of mean differences, respectively), as well as the high values of the upper and lower limits of agreement. We conclude that the VO2PEAK values obtained in the incremental phase of the LM underestimate the VO2MAX. Key pointsThe VO2MAX is not attained during the incremental phase of the lactate minimum test;The physiological responses at exhaustion during LM are not similar to physiological responses measured during GXT;There is a weak agreement between the peak VO2 measured at exhaustion during LM and the VO2MAX measured during GXT.

Influence of the selection from incremental stages on lactate minimum intensity: a pilot study / Influência da seleção dos estágios incrementais sobre a intensidade de lactato mínimo: estudo piloto

The purposes of this study were to assess the influence of stage selection from the incremental phase and the use of peak lactate after hyperlactatemia induction on the determination of the lactate minimum intensity (iLACmin). Twelve moderately active university students (23±5 years, 78.3±14.1 kg, 175.3±5.1 cm) performed a maximal incremental test to determine the respiratory compensation point (RCP) (initial intensity at 70 W and increments of 17.5 W every 2 minutes) and a lactate minimum test (induction with the Wingate test, the incremental test started at 30 W below RCP with increments of 10 W every 3 minutes) on a cycle ergometer. The iLACmin was determined using second order polynomial adjustment applying five exercise stage selection: 1) using all stages (iL-ACminP); 2) using all stages below and two stages above iLACminP (iLACminA); 3) using two stages below and all stages above iLACminP (iLACminB); 4) using the largest and same possible number of stages below and above the iLACminP (iLACminI); 5) using all stages and peak lactate after hyperlactatemia induction (iLACminD). No differences were found between the iLACminP (138.2±30.2 W), iLACminA (139.1±29.1 W), iLACminB (135.3±14.2 W), iLACminI (138.6±20.5 W) and iLACmiD (136.7±28.5 W) protocols, and a high level of agreement between these intensities and iLACminP was observed. Oxygen uptake, heart rate, rating of perceived exertion and lactate corresponding to these intensities was not different and was strongly correlated. However, the iLACminB presented the lowest success rate (66.7%). In conclusion, stage selection did not influence the determination of iLACmin but modified the success rate.

Os objetivos foram verificar a influência da seleção de estágios da fase incremental e o uso do lactato pico após indução hiperlactacidêmica na determinação da intensidade de lactato mínimo (iLACmin). Doze universitários moderadamente ativos (23±5 anos, 78,3±14,1 kg, 175,3± 5,1 cm) realizaram um teste incremental máximo para determinação do ponto de compensação respiratório (PCR) (início a 70 W e incrementos de 17,5 W a cada 2 minutos) e um teste de lactato mínimo (indução com Wingate, fase incremental iniciado a 30 W abaixo do PCR e incrementos de 10 W a cada 3 minutos) em cicloergômetro. A iLACmin foi determinada utilizando ajuste polinomial de segunda ordem, aplicando cinco seleções de estágios da fase incremental: 1) Utilizando todos os estágios obtidos (iLACminP); 2) Utilizando todos os estágios antes e dois após à iLACminP (iLACminA); 3) Utilizando dois estágios antes e todos após à iLACminP (iLACminB); 4) Utilizando o maior e mesmo número possível de estágios anteriores e posteriores à iLACminP (iLACminI); 5) Utilizando todos os estágios e o lactato pico após indução (iLACminD). Não foram encontradas diferenças entre iLACminP (138,2±30,2 W), iLACminA (139,1±29,1 W), iLACminB (135,3±14,2 W), iLACminI (138,6±20,5 W), iLACmiD (136,7±28,5 W) e verificou-se alta concordância entre essas intensidades e iLACminP. O consumo de oxigênio, frequência cardíaca, percepção subjetiva de esforço e lactato nessas intensidades não diferiram e foram fortemente correlacionadas. Entretanto, a iLACminB apresentou o menor índice de sucesso (66,7%). Conclui-se que a seleção de estágios não influenciou na determinação da iLACmin, mas alterou o índice de sucesso.

Utilização da distância total percorrida no teste específico de hoff como preditor da velocidade de limiar anaeróbio no futebol / Use of maximal running distance performed on hoff test for anaerobic threshold prediction in soccer

OBJETIVO: Verificar a utilização da distância total percorrida no teste de Hoff como preditor da intensidade de limiar anaeróbio em jovens futebolistas. MÉTODOS: Para isso, 10 jovens jogadores de futebol (idade de 17 ± 1 ano e massa corporal de 64,3 ± 2,1 kg) participaram do estudo. Os sujeitos foram submetidos aos testes de 12 minutos, lactato mínimo para estimar a velocidade de limiar anaeróbio (vLAn) e ao teste de Hoff específico para o de futebol. O objetivo no teste de Hoff foi percorrer a máxima distância possível em 10 minutos de exercício conduzindo a bola de futebol em um circuito composto por dribles, saltos e corridas em direções diversas. RESULTADOS: A distância total percorrida no teste de 12 minutos foi 2.673,2 ± 64,7 m, a vLAn 11,6 ± 0,3 km.h-1 e a distância percorrida no Hoff 1.458,7 ± 49,6 m. A distância total percorrida no teste de Hoff não foi significativamente correlacionada com a vLAn (r = -0,20; P < 0,05) e com a distância percorrida no teste de 12 minutos (r = -0,15; P < 0,05). No entanto, a vLAn e a velocidade correspondente a 90% da velocidade média no teste de 12 minutos (12,0 ± 0,3 km.h-1) não foram diferentes significativamente e foram significativamente correlacionadas (r = 0,65; P < 0,05). CONCLUSÃO: Assim, pode-se concluir que a distância total percorrida no teste de Hoff não pode ser utilizada para predição da velocidade de limiar anaeróbia em futebolistas.

OBJECTIVE: To verify the use of maximal running distance performed on Hoff test to predict the anaerobic threshold speed (sAnT). METHODS: Ten young soccer players (age of 17 ± 1 years and body mass of 64.3 ± 2.1 kg) were subjects of the study. The subjects performed 12-min test, lactate minimum test to estimate the anaerobic threshold speed and a field test called Hoff. The purpose of Hoff test was to cover the maximum distance during a period of 10min moving a soccer ball through the track by dribbling. RESULTS: The distance covered during 12-min was 2673.2 ± 64.7 m, the sAnT was 11.6 ± 0.3 km.h-1 and distance covered during test Hoff test was 1458.7 ± 49.6 m. The distance covered during Hoff test was not significantly correlated with sAnT (r = -0.20; P > 0.05) and distance covered during 12-min test (r = -0.15; P > 0.05). The sAnT did not differ of speed correspondent 90% at 12-min speed and they were statistically correlated (r = 0.65). CONCLUSION: Thus, we concluded that maximal distance covered during Hoff test cannot provides a valid prediction of the anaerobic threshold speed.