Anaerobic Energy Expenditure Research Articles

Resistance Exercise Sessions Comprising Multijoint vs. Single-Joint Exercises Result in Similar Metabolic and Hormonal Responses, But Distinct Levels of Muscle Damage in Trained Men.

Barbosa, PH, Bueno de Camargo, JB, Jonas de Oliveira, J, Reis Barbosa, CG, Santos da Silva, A, Dos-Santos, JW, Verlengia, R, Barreira, J, Braz, TV, and Lopes, CR. Resistance exercise sessions comprising multijoint vs. single-joint exercises result in similar metabolic and hormonal responses, but distinct levels of muscle damage in trained men. J Strength Cond Res 38(5): 842-847, 2024-Resistance-type exercise (RE) elicits distinct acute metabolic and hormonal responses, which can be modulated by the manipulation of training variables. The purpose of this study was to compare the metabolic (blood lactate and estimated lactic anaerobic system energy expenditure) and hormonal (growth hormone [GH]) responses to RE sessions composed exclusively of multijoint (MULTI) or single-joint (SINGLE) exercises. Assessments of creatine kinase (CK) levels were also performed. In a crossover design, 10 recreationally resistance-trained men (age: 26.9 ± 3.0 years, total body mass: 83.2 ± 13.8 kg; height: 176 ± 7.0 cm; training experience: 5.5 ± 2.4 years) were randomly submitted to both protocols. Blood collections were made pre, 3 minutes after, and 36 hours after each experimental session. No significant difference between MULTI vs. SINGLE was observed for the rises in blood lactate (p = 0.057) and GH (p = 0.285) levels. For CK, a significant difference between the protocols was noted, in which MULTI resulted in significant rises after 3 minutes (p = 0.017) and 36 hours (p = 0.043) compared with SINGLE. In conclusion, the findings of this study suggest that resistance-trained individuals display similar metabolic and hormonal responses when performing MULTI and SINGLE exercise protocols. Also, RE sessions comprising MULTI exercises induce a higher magnitude of muscle damage, which may require a longer recovery period compared with SINGLE.

The effect of exercise hyperpnea on gross efficiency and anaerobic capacity estimates during a 3-min cycle time trial.

This study aimed to analyze the effect of exercise-induced hyperpnea on gross efficiency (GE) and anaerobic capacity estimates during a self-paced 3-min supramaximal cycle time trial (TT). Fourteen highly trained male cyclists performed 7 × 4-min submaximal stages, a 6-min passive rest, a 3-min TT, a 5-min passive rest, and a 6-min submaximal stage. Three models were based on the 7 × 4-min linear regression extrapolation method, using 1) the conventional model (7-YLIN); 2) the same 7-YLIN model but correcting for the additional ventilatory cost (i.e., hyperpnea) (7-YLIN-V-cor); and 3) accounting for linearly declining GE during the TT (7-YLIN-D). The other three models were based on GE from the last submaximal stage, using the conventional model (GELAST) and the same modifications as described for 7+YLIN, i.e., 1) GELAST, 2) GELAST-V-cor, and 3) GELAST-D. The GELAST model generated 18% higher values of anaerobic capacity than the 7-YLIN model (P < 0.05). During the TT, the hyperpnea-corrected model (i.e., 7-YLIN-V-cor or GELAST-V-cor) generated, compared with the respective conventional model (i.e., 7-YLIN or GELAST), ∼0.7 percentage points lower GE and ∼11% higher anaerobic capacity (all, P < 0.05). The post-TT GE was 1.9 percentage points lower (P < 0.001) and the 7-YLIN-D or GELAST-D model generated, compared with the respective conventional model, a lower GE (∼1.0 percentage points) and ∼17% higher anaerobic capacity during the TT (all, P < 0.05). In conclusion, the correction for a declining GE due to hyperpnea during a supramaximal TT resulted in an increased required total metabolic rate and anaerobic energy expenditure compared with the conventional models.NEW & NOTEWORTHY This study demonstrates that GE declines during a 3-min supramaximal cycle TT, which is possibly related to the hyperpneic response during supramaximal exercise. The finding from this study also provides novel insight into how the increased ventilatory energy cost from exercise-induced hyperpnea contributes to decreased GE, increased required total metabolic rate, and increased anaerobic energy expenditure during supramaximal exercise. Therefore, conventional linear models for estimating anaerobic capacity are likely to generate underestimated values.

Prolonged cycling lowers subsequent running mechanical efficiency in collegiate triathletes

BackgroundA significant challenge that non-elite collegiate triathletes encounter during competition is the decline in running performance immediately after cycling. Therefore, the purpose of this study was to determine if performing a 40-km bout of cycling immediately before running would negatively influence running economy and mechanical efficiency of running during simulated race conditions in collegiate triathletes.MethodsEight competitive club-level collegiate triathletes randomly performed two trials: cycling for 40 km (Cycle-Run) or running for 5 km (Run–Run), immediately followed by a four-minute running economy and mechanical efficiency of running test at race pace on an instrumented treadmill. Blood lactate, respiratory exchange ratio, mechanical work, energy expenditure, and muscle glycogen were also measured during the four-minute running test.ResultsMechanical efficiency of running, but not running economy, was significantly lower in Cycle-Run, compared to Run–Run (42.1 ± 2.5% vs. 48.1 ± 2.5%, respectively; p = 0.027). Anaerobic energy expenditure was significantly higher in the Cycle-Run trial, compared to the Run–Run trial (16.3 ± 2.4 vs. 7.6 ± 1.1 kJ; p = 0.004); while net (151.0 ± 12.3 vs. 136.6 ± 9.6 kJ; p = 0.204) and aerobic energy expenditure (134.7 ± 12.3 vs. 129.1 ± 10.5 kJ; p = 0.549) were not statistically different between trials. Analysis of blood lactate, respiratory exchange ratio, mechanical work, and changes in muscle glycogen revealed no statistically significant differences between trials.ConclusionsThese results suggest that mechanical efficiency of running, but not running economy, is decreased and anaerobic energy expenditure is increased when a 40-km bout of cycling is performed immediately before running in collegiate triathletes.

Validity and Reliability of Hydraulic-Analogy Bioenergetic Models in Sprint Roller Skiing.

Purpose: To develop a method for individual parameter estimation of four hydraulic-analogy bioenergetic models and to assess the validity and reliability of these models’ prediction of aerobic and anaerobic metabolic utilization during sprint roller-skiing.Methods: Eleven elite cross-country skiers performed two treadmill roller-skiing time trials on a course consisting of three flat sections interspersed by two uphill sections. Aerobic and anaerobic metabolic rate contributions, external power output, and gross efficiency were determined. Two versions each (fixed or free maximal aerobic metabolic rate) of a two-tank hydraulic-analogy bioenergetic model (2TM-fixed and 2TM-free) and a more complex three-tank model (3TM-fixed and 3TM-free) were programmed into MATLAB. The aerobic metabolic rate (MRae) and the accumulated anaerobic energy expenditure (Ean,acc) from the first time trial (STT1) together with a gray-box model in MATLAB, were used to estimate the bioenergetic model parameters. Validity was assessed by simulation of each bioenergetic model using the estimated parameters from STT1 and the total metabolic rate (MRtot) in the second time trial (STT2).Results: The validity and reliability of the parameter estimation method based on STT1 revealed valid and reliable overall results for all the four models vs. measurement data with the 2TM-free model being the most valid. Mean differences in model-vs.-measured MRae ranged between -0.005 and 0.016 kW with typical errors between 0.002 and 0.009 kW. Mean differences in Ean,acc at STT termination ranged between −4.3 and 0.5 kJ and typical errors were between 0.6 and 2.1 kJ. The root mean square error (RMSE) for 2TM-free on the instantaneous STT1 data was 0.05 kW for MRae and 0.61 kJ for Ean,acc, which was lower than the other three models (all P < 0.05). Compared to the results in STT1, the validity and reliability of each individually adapted bioenergetic model was worse during STT2 with models underpredicting MRae and overpredicting Ean,acc vs. measurement data (all P < 0.05). Moreover, the 2TM-free had the lowest RMSEs during STT2.Conclusion: The 2TM-free provided the highest validity and reliability in MRae and Ean,acc for both the parameter estimation in STT1 and the model validity and reliability evaluation in the succeeding STT2.

Metabolic Profile of Reciprocal Supersets in Young, Recreationally Active Women and Men.

Realzola, RA, Mang, ZA, Millender, DJ, Beam, JR, Bellovary, BN, Wells, AD, Houck, JM, and Kravitz, L. Metabolic profile of reciprocal supersets in young, recreationally active females and males. J Strength Cond Res 36(10): 2709-2716, 2022-Reciprocal supersets (RSSs) are a time-efficient style of resistance exercise (RE) that consist of performing 2 consecutive exercises with opposing muscle groups while limiting rest times between them. Previous research in men indicates a RSS has an increased physiological response when compared with traditional RE (TRAD). No between-sex comparison of metabolic data for RSSs exists. The purpose of this study was to create a metabolic profile for RSSs in men and women. Eighteen resistance-trained individuals underwent 2 bouts of volume-load equated RE: RSS and TRAD. Reciprocal superset exercises were split into 3 clusters: (a) hexagonal bar deadlift superset with leg press, (b) chest press superset with seated row, and (c) overhead dumbbell press superset with latissimus dorsi pull-downs. The TRAD protocol, doing the same exercises, emulated hypertrophy emphasis training. Oxygen uptake (V̇ o2 ), heart rate (HR), blood lactate ([BLa]), rate of perceived exertion (RPE), and excess post-exercise oxygen consumption (EPOC) were measured. Aerobic and anaerobic energy expenditure were estimated using V̇ o2 and lactate, respectively. The level of significance set for this study was p ≤ 0.05. Regardless of sex, a RSS elicited significantly greater average V̇ o2 , HR, [BLa], RPE, and anaerobic and aerobic energy expenditures, and was completed in a shorter time compared with TRAD ( p ≤ 0.05). When compared with women, men had significantly greater EPOC, average [BLa], and anaerobic and aerobic energy expenditures during RSSs ( p ≤ 0.05). The average [BLa] and aerobic energy expenditure of the men were also significantly greater than the women during TRAD ( p ≤ 0.05). This study suggests that a RSS is a metabolically demanding RE session that may elicit increases in musculoskeletal, cardiorespiratory, and physiological adaptations while decreasing the duration of exercise.

Effects Of w’ Depletion On The Torque Velocity Relationship In Cycling

The torque-velocity (T-v) curve has been used to study the effects of energy expenditure on contractile muscles at various workloads related to VO2max. PURPOSE: The purpose of this study was to further quantify changes to the T-v curve, but based on anaerobic energy (W’) expenditure at powers above Critical Power (CP6). METHODS: A group of 10 subjects (37.8 ± 11.6 yrs, 72.8 ± 16.2 kg, 1.75 ± .11 m) performed a Time to Exhaustion Test (TTE) interspersed with 6-second sprints to generate their T-v curve at 3 stages of W’ expenditure: after initial warmup (FRESH), fatigued (after 2 minutes at CP6, 2MIN), and at TTE. RESULTS: ANOVA results indicated a statistically significant decrease in normalized Maximal Power (Pmax) from FRESH to 2MIN (16.89%, p<.0005), 2MIN to TTE (24.71%, p=.004), and from FRESH to TTE (41.6% p=.04). Statistically significant decreases in normalized Maximal Velocity (vo) were seen from FRESH to 2MIN (14.1%, p<.0005), from 2MIN to TTE (11.8%, p=.001), and FRESH to TTE (25.9%, p<.0005). No significant changes occurred in Maximal Torque (To). Linear regression models were run using W’ expended to explain variations in Pmax, vo, and To. There were significant negative correlations for To (P = 0.020) and significant strong negative correlations for Pmax (P < 0.005), and vo (P < 0.005). CONCLUSIONS: This suggests that W’ expenditure can be used to predict the performance parameters Torque (To), Shortening velocity (vo), and Maximal Power (Pmax) during continuous cycling above Critical Power.

Взаимосвязь психологических особенностей личности с гормональными сдвигами при гиперкинезии

The purpose of this research was to study the correlation between the person’s psychological features and the level of hormones in athletes’ (exercising mostly in aerobic or anaerobic energy expenditure modes) blood serum. Athletes who exercised in different energy expenditure modes demonstrated different levels of unproductive neuropsychic stress: athletes exercising mostly in aerobic mode had low and medium levels of unproductive neuropsychic stress, those exercising mostly in anaerobic mode had medium and high stress levels in the majority of cases. Athletes with different levels of unproductive neuropsychic stress had significant differences in insulin, somatotropin, adrenocorticotropic hormone in their blood serum when having a physiological rest and after graded cycloergometric loads. The revealed shifts reflect peculiarities of recovery processes after muscle activity and indicate a great impact of a neuropsychic stress level on the organism’s adaptation to hyperkinesia

Metabolic Power in Team Sports - Part 2: Aerobic and Anaerobic Energy Yields.

A previous approach to estimate the time course of instantaneous metabolic power and O2 consumption in team sports has been updated to assess also energy expenditure against air resistance and to identify walking and running separately. Whole match energy expenditure turned out ≈14% smaller than previously obtained, the fraction against the air resistance amounting to ≈2% of the total. Estimated net O2 consumption and overall energy expenditure are fairly close to those measured by means of a portable metabolic cart; the average difference, after a 45 min exercise period of variable intensity and mode, amounting to ≈10%. Aerobic and anaerobic energy yields, metabolic power, energy expenditure and duration of High (HI) and Low (LI) intensity bouts can also be estimated. Indeed, data on 497 soccer players during the 2014/2015 Italian "Serie A" show that the number of HI efforts decreased from the first to the last 15-min periods of the match, without substantial changes in mean metabolic power (≈22 W·kg-1) and duration (≈6.5 s). On the contrary, mean metabolic power of the LI decreased (5.8 to 4.8 W·kg-1), mainly because of a longer duration thereof, thus underscoring the need for longer recovery periods between HI.

Caffeine Increases Work Done above Critical Power, but Not Anaerobic Work.

The assumption that the curvature constant (W') of the power-duration relationship represents anaerobic work capacity is a controversial, unresolved question. We investigated if caffeine ingestion could increase total work done above critical power (CP), and if this would be accompanied by greater anaerobic energy expenditure and by an enhanced maintenance of maximal oxidative metabolic rate. Nine men (26.6 ± 5.3 yr, V˙O2max 40.6 ± 5.8 mL·kg·min) cycled until exhaustion at different exercise intensities on different days to determine the CP and W'. On separated days, participants cycled until exhaustion in the severe-intensity domain (136% ± 7% of CP) after ingesting either caffeine (5 mg·kg body mass) or a placebo. Time to exhaustion was 34% longer with caffeine compared with placebo, and this was accompanied by a greater work done above CP (23.7 ± 5.7 vs 17.5 ± 3.6 kJ; 130% ± 30% vs 95% ± 14% of W', P < 0.01). Caffeine increased the aerobic energy expenditure (296.4 ± 91.0 vs 210.2 ± 71.9 kJ, P < 0.01), but not anaerobic lactic, anaerobic alactic, and total anaerobic (lactic + alactic) energy expenditure. The end values of heart rate and ventilation were higher with caffeine, but the V˙O2 end was similar between conditions and was not different from V˙O2max. Caffeine did not change time to reach V˙O2max but increased time maintained at V˙O2max (199.3 ± 105.9 vs 111.9 ± 87.1 s, P < 0.05). Caffeine increased total work done above CP, but this was not associated with greater anaerobic work. Rather, this was associated with a higher tolerance to maintain exercise at maximal oxidative metabolic rate.

Acidosis, but Not Alkalosis, Affects Anaerobic Metabolism and Performance in a 4-km Time Trial.

This study aimed to determine the effect of preexercise metabolic acidosis and alkalosis on power output (PO) and aerobic and anaerobic energy expenditure during a 4-km cycling time trial (TT). Eleven recreationally trained cyclists (V˙O2peak 54.1 ± 9.3 mL·kg·min) performed a 4-km TT 100 min after ingesting in a double-blind matter 0.15 g·kg of body mass of ammonium chloride (NH4Cl, acidosis), 0.3 g·kg of sodium bicarbonate (NaHCO3, alkalosis), or 0.15 g·kg of CaCO3 (placebo). A preliminary study (n = 7) was conducted to establish the optimal doses to promote the desirable preexercise blood pH alterations without gastrointestinal distress. Data for PO, aerobic and anaerobic energy expenditure, and blood and respiratory parameters were averaged for each 1 km and compared between conditions using two-way repeated-measures ANOVA (condition and distance factors). Gastrointestinal discomfort was analyzed qualitatively. Compared with placebo (pH 7.37 ± 0.02, [HCO3]: 27.5 ± 2.6 mmol·L), the NaHCO3 ingestion resulted in a preexercise blood alkalosis (pH +0.06 ± 0.04, [HCO3]: +4.4 ± 2.0 mmol·L, P < 0.05), whereas NH4Cl resulted in a blood acidosis (pH -0.05 ± 0.03, [HCO3]: -4.8 ± 2.1 mmol·L, P < 0.05). Anaerobic energy expenditure rate and PO were reduced throughout the trial in NH4Cl compared with placebo and NaHCO3, resulting in a lower total anaerobic work and impaired performance (P < 0.05). Plasma lactate, V˙CO2, and end-tidal CO2 partial pressure were lower and the V˙E/V˙CO2 higher throughout the trial in NH4Cl compared with placebo and NaHCO3 (P < 0.05). There was no difference between NaHCO3 and placebo for any of these variables (P > 0.05). Minimal gastrointestinal distress was noted in all conditions. Preexercise acidosis, but not alkalosis, affects anaerobic metabolism and PO during a 4-km cycling TT.

P32 heterozygosity protects against age- and diet-induced obesity by increasing energy expenditure

Obesity is increasing in prevalence and has become a global public health problem. The main cause of obesity is a perturbation in energy homeostasis, whereby energy intake exceeds energy expenditure. Although mitochondrial dysfunction has been linked to the deregulation of energy homeostasis, the precise mechanism is poorly understood. Here, we identify mitochondrial p32 (also known as C1QBP) as an important regulator of lipid homeostasis that regulates both aerobic and anaerobic energy metabolism. We show that while whole-body deletion of the p32 results in an embryonic lethal phenotype, mice heterozygous for p32 are resistant to age- and high-fat diet-induced ailments, including obesity, hyperglycemia, and hepatosteatosis. Notably, p32+/− mice are apparently healthy, demonstrate an increased lean-to-fat ratio, and show dramatically improved insulin sensitivity despite prolonged high-fat diet feeding. The p32+/− mice show increased oxygen consumption and heat production, indicating that they expend more energy. Our analysis revealed that haploinsufficiency for p32 impairs glucose oxidation, which results in a compensatory increase in fatty acid oxidation and glycolysis. These metabolic alterations increase both aerobic and anaerobic energy expenditure. Collectively, our data show that p32 plays a critical role in energy homeostasis and represents a potential novel target for the development of anti-obesity drugs.

Cardiovascular Fitness and Energy Expenditure Response during a Combined Aerobic and Circuit Weight Training Protocol.

ObjectivesThe present study describes the oxygen uptake and total energy expenditure (including both aerobic and anaerobic contribution) response during three different circuit weight training (CWT) protocols of equivalent duration composed of free weight exercises, machine exercises, and a combination of free weight exercises intercalating aerobic exercise.DesignControlled, randomized crossover designs.MethodsSubjects completed in a randomized order three circuit weight training protocols of the same duration (3 sets of 8 exercises, 45min 15s) and intensity (70% of 15 repetitions maximum). The circuit protocols were composed of free weight exercises, machine exercises, or a combination of free weight exercises with aerobic exercise. Oxygen consumption and lactate concentration were measured throughout the circuit to estimate aerobic and anaerobic energy expenditure respectively.ResultsEnergy expenditure is higher in the combined exercise protocol (29.9±3.6 ml/kg/min), compared with Freeweight (24.2±2.8ml/kg/min) and Machine (20.4±2.9ml/kg/min). The combined exercise protocol produced the highest total energy expenditure but the lowest lactate concentration and perceived exertion. The anaerobic contribution to total energy expenditure was higher in the machine and free weight protocols compared with the combined exercise protocol (6.2%, 4.6% and 2.3% respectively).ConclusionsIn the proposed protocols, the combined exercise protocol results in the highest oxygen consumption. Total energy expenditure is related to the type of exercise included in the circuit. Anaerobic contributions to total energy expenditure during circuit weight training may be modest, but lack of their estimation may underestimate total energy expenditure.Trial RegistrationClinicalTrials.gov NCT01116856

Swimming speeds and metabolic rates of semi-captive juvenile lemon sharks (Negaprion brevirostris, Poey) estimated with acceleration biologgers

There is much interest in being able to quantify the swimming speeds and metabolic rates of wild aquatic animals such as sharks to develop bioenergetics models and evaluate the metabolic consequences of different stressors. This study sought to calibrate tri-axial acceleration biologgers (accelerometers) such that it would be possible to estimate swimming speeds and metabolic rates of semi-captive sharks in an enclosed natural mesocosm. Juvenile lemon sharks (Negaprion brevirostris, Poey; 60–75cm total length, 1–2kg) were equipped with accelerometers and swum at stepwise velocity increments in a Blazka-style swim tunnel respirometer using a critical swimming speed protocol. Metabolic rates and acceleration-derived metrics (overall dynamic body acceleration and tailbeat frequency) were measured concurrently during forced swimming, and accelerometer-equipped sharks were released to an enclosed mesocosm habitat to estimate average daily metabolic rate (ADMR) and swimming velocities across diel and tidal cycles. Acceleration-derived tailbeat frequency was a stronger predictor of metabolic rate than overall dynamic body action, and predicted an active metabolic rate of 249.7±1.9mg O2 kg−1h−1 and an ADMR of 88.7±0.7kJkg−1d−1 at 30°C. Following exhaustive exercise a maximum metabolic rate of 398.0±19.6mg O2 kg−1h−1 was achieved and over the subsequent 55-minute recovery period excess post-exercise oxygen consumption was 31.2mg O2 kg−1. The critical swimming speed of the sharks was 0.71±0.03 body lengths per second (BL s−1), and swimming speed in the mesocosm was 0.19±0.01 BL s−1. Locomotor activity levels of semi-captive sharks in the mesocosm were influenced by tide state and diel period, with sharks having highest swimming velocities during diurnal periods and flooding tides. Overall, accelerometry is a suitable means for estimating swimming speed and metabolic rate in this species, and additional research to address anaerobic energy expenditure of wild sharks is warranted.

Is there a pace-of-life syndrome linking boldness and metabolic capacity for locomotion in bluegill sunfish?

The concept of behavioural syndromes (i.e. correlations between behavioural traits) has provided an important framework for understanding individual variation in animal behaviour and its link to individual variation in physiology and life-history traits. The pace-of-life syndrome concept posits that behavioural, physiological and life-history traits coevolve in response to correlated selection pressures, and therefore predicts a positive correlation between boldness (i.e. exploration and risk taking) and metabolic capacity for locomotor performance in individuals. We tested for a pace-of-life syndrome linking boldness and metabolic capacity for locomotor activity in juvenile bluegill sunfish, Lepomis macrochirus. Individual fish were screened and classified as bold or shy using an established refuge emergence test. Subsequently, the aerobic and anaerobic metabolisms of bold and shy individuals were quantified using respirometry and by measuring the metabolic by-products of white muscle anaerobic glycolysis following exhaustive exercise, respectively. Bold fish demonstrated 25% greater metabolic scope for activity (i.e. aerobic capacity) than shy fish, which was attributable to a 15% greater maximum metabolic rate. However, there was no significant difference in resting metabolic rate or anaerobic energy expenditure (i.e. anaerobic capacity) between bold and shy fish. These results partially support a pace-of-life syndrome linking boldness and aerobic metabolism in juvenile bluegill sunfish, but did not reveal a link between boldness and anaerobic metabolism. Our findings suggest that aerobic and anaerobic capacities may be subject to different selection pressures, and that physiological processes governing maximum anaerobic performance in fishes are independent from behavioural and physiological traits related to boldness.

Efeitos agudos de diferentes métodos de treinamento com pesos sobre o gasto energético em homens treinados

INTRODUCAO: O treinamento com pesos vem sendo amplamente utilizado como estrategia de controle e reducao ponderal, assim o gasto energetico (GE) contribui de forma significativa para este processo. OBJETIVO: Comparar os efeitos agudos do metodo circuito (MC) com o metodo tradicional (MT) sobre o GE. METODOS: Trata-se de uma pesquisa com delineamento crossover e aleatorizado, a amostra foi composta por 10 homens adultos treinados com idade entre 18 e 29 anos. Foram realizadas duas sessoes experimentais com wash out de sete dias: no MC os exercicios foram realizados alternados por segmento em forma de estacoes, durante o MT os exercicios foram realizados em series consecutivas. Ambos os metodos seguiram a mesma sequencia de oito exercicios com o mesmo trabalho total: 60% de 1RM, 24 series/estacoes e 10 repeticoes. O lactato sanguineo foi coletado em repouso e a cada tres series/estacoes. O ar expirado foi coletado por 30 minutos antes e ~31 minutos durante todas as sessoes de treinamento. O GE aerobio de exercicio (GEAE, kj) e do intervalo de recuperacao (GEAIR, kj) foram estimados pela calorimetria indireta atraves da medida do consumo de oxigenio e o GE anaerobio (GEA, kj) pela concentracao de lactato sanguineo ([La]). O GE total (GET, kj) foi registrado pelo somatorio do GEA, GEAE e GEAIR. RESULTADOS: Os dados demonstraram que o GEA foi maior no MT do que o MC, no entanto, o GEAE, GEAIR e o GET nao foram diferentes significativamente entre os metodos. O MT apresentou maior [La] do que o MC. CONCLUSAO: Conclui-se que o MC e o MT produzem similar GET, contudo, percebe-se que o MT utiliza mais a via anaerobia do que o MC.

Prediction of Rowing Performance by Using Critical Thresholds in Elite Female Rowers

The purpose of this study was to compare the different critical thresholds, critical velocity (CV) and critical power (CP), combining with anaerobic power and energy expenditure to predict the 2,000m indoor performance of female rowers in Taiwan. Fifteen elite female rowers (age 20.7±1.4 years, height 164±3.5cm, weight 56.6±4.4kg) were recruited for this study. By using counter-balanced design order, 4 time-trials on 90s, 240s, 600s and 1,200s were underwent to determine the CP (139.5±20.4W), whereas CV (4.0±0.1 m/s) was derived by 400m, 600m, 800m and 1,000m distance-trials on different days by using linear distance-time model. Maximal oxygen uptake (VO2peak=2.5±0.5L/min) and anaerobic threshold (AT4=157.8±22.1W) were obtained from an incremental exercise test. Further, anaerobic capacity (6,912.1±895.6W), mean power (323.2±26.7W) and fatigue index (3.8±2.6%) were obtained using a modified Wingate protocol on rowing ergometer followed by a 2,000 m time-trial. The results showed that CV, CP as well as VO2peak and AT4 were significantly correlated with 2,000 m indoor rowing performance. Stepwise regression analysis indicated CV and fatigue index (FI) were most important determinants in establishing predicting model of 2,000 m indoor rowing performance (T2000=-131.44 CV-89.57 FI+1022.27, SEE=4.08s). This study concludes that both CV and CP were significant correlated with 2,000m indoor rowing performance. CV and FI constructed the best predicting model for indoor rowing performance of female rowers in Taiwan.

The effect of time-under-tension and weight lifting cadence on aerobic, anaerobic, and recovery energy expenditures: 3 submaximal sets

We examined the aerobic and anaerobic energy expenditures of weight lifting (bench press); submaximal work was kept constant among protocols. Ten male subjects (age, 23.2 ± 3.1 years; height, 177.3 ± 5.3 cm; weight, 82.1 ± 11.5 kg) were randomly assigned to 3 lifting sessions of 3 sets of 5 repetitions at 70% 1 repetition maximum (1RM) using 3 lifting cadences: 1.5 s down and 1.5 s up (15 s per set), 4 s down and 1 s up (25 s per set), and 1 s down and 4 s up (25 s per set). No differences were found among the aerobic exercise energy expenditures for each lifting cadence. However, anaerobic energy expenditure was significantly different among protocols: 1.5 down-1.5 up, 16.5 ± 8.1 kJ; 4 down-1 up, 21.6 ± 8.1 kJ; and 1 down-4 up, 26.7 ± 7.2 kJ (p = 0.001). Excess postexercise oxygen consumption (EPOC; after each set) was lower for 1.5 down-1.5 up, 38.6 ± 17.8 kJ; versus 4 down-1 up, 50.2 ± 23.5 kJ; and 1 down-4 up, 50.0 ± 22.6 kJ (p = 0.002). Total energy expenditure also was significantly less for 1.5 up-1.5 down, 60.2 ± 23.8 kJ; versus 4 down-1 up, 80.0 ± 27.7 kJ; and 1 down-4 up, 84.2 ± 28.3 kJ (p = 0.001). Differences in EPOC and total energy expenditure with submaximal lifting were based not on the amount of work performed or with a particular eccentric-concentric cadence, but on the time to completion of the weight lifting exercise - time-under-tension; longer submaximal lifting times had greater energy expenditure.

Glucose and Fat Oxidation: Bomb Calorimeter Be Damned

For both respiration and combustion, the energy loss difference between glucose and fat oxidation often is referenced to the efficiency of the fuel. Yet, the addition of anaerobic metabolism with ATP resynthesis to complete respiratory glucose oxidation further contributes to energy loss in the form of entropy changes that are not measured or quantified by calorimetry; combustion and respiratory fat/lactate oxidation lack this anaerobic component. Indeed, the presence or absence of an anaerobic energy expenditure component needs to be applied to the estimation of energy costs in regard to glucose, lactate, and fuel oxidation, especially when the measurement of oxygen uptake alone may incorrectly define energy expenditure.

Energy Expenditure During Tennis Play: A Preliminary Video Analysis and Metabolic Model Approach

The aim of this study was to estimate, using video analysis, what proportion of the total energy expenditure during a tennis match is accounted for by aerobic and anaerobic metabolism, respectively. The method proposed involved estimating the metabolic power (MP) of 5 activities, which are inherent to tennis: walking, running, hitting the ball, serving, and sitting down to rest. The energy expenditure concerned was calculated by sequencing the activity by video analysis. A bioenergetic model calculated the aerobic energy expenditure (EEO2mod) in terms of MP, and the anaerobic energy expenditure was calculated by subtracting this (MP - EEO2mod). Eight tennis players took part in the experiment as subjects (mean ± SD: age 25.2 ± 1.9 years, weight 79.3 ± 10.8 kg, VO2max 54.4 ± 5.1 ml·kg(-1)·min(-1)). The players started off by participating in 2 games while wearing the K4b2, with their activity profile measured by the video analysis system, and then by playing a set without equipment but with video analysis. There was no significant difference between calculated and measured oxygen consumptions over the 16 games (p = 0.763), and these data were strongly related (r = 0.93, p < 0.0001). The EEO2mod was quite weak over all the games (49.4 ± 4.8% VO2max), whereas the MP during points was up to 2 or 3 times the VO2max. Anaerobic metabolism reached 32% of the total energy expenditure across all the games 67% for points and 95% for hitting the ball. This method provided a good estimation of aerobic energy expenditure and made it possible to calculate the anaerobic energy expenditure. This could make it possible to estimate the metabolic intensity of training sessions and matches using video analysis.

Aerobic, Anaerobic, And Excess Post-exercise Oxygen Consumption Energy Expenditure Of Rope Training

Rope training has emerged in many fitness centers as a popular group fitness activity. Rope training consists of an individual waving 30-50 feet of rope as fast as they can for 15-30 seconds. To date, no studies have examined the energy expenditure (EE) of rope training. PURPOSE: The purpose of this study was to determine the aerobic, anaerobic, and excess post-exercise oxygen consumption (EPOC) EE from an acute bout of 10 minutes of rope training. METHODS: A total of 11 physically active participants (5 male, 6 female, mean age 24.7 ± 1.9 years) were recruited for this study. Participants were instructed to not exercise on the day of testing and to fast at least 4 hours prior to testing. All participants used a nylon rope (50 feet, 36 pounds, 1.5 inches) anchored by a post, resulting in the participant holding 25 feet of rope in each hand. The 10 minute rope protocol consisted of 15 seconds of vertical double arm waves followed by 45 seconds of rest, for 10 repetitions. Heart rate, resting VO2, exercise VO2, and EPOC were measured via metabolic cart. VO2 was recorded until 2 consecutive measurements were within ± 5% of resting O2 uptake, with the post-exercise VO2 used to calculate EPOC. Anaerobic EE was determined from the difference between peak and resting blood lactate measures, multiplied by body weight, then by 3.0 ml of O2. Total energy expenditure (TEE) was calculated by summing aerobic, anaerobic, and EPOC EE. RESULTS: The average heart rate for the workout was 162.5 ± 10.8 bpm (83% of age predicted max). Aerobic EE was 86.6 ± 30.7 kcal. Anaerobic EE was 12.2 ± 3.4 kcal. EE attributed to EPOC was 12.9 ± 5.3 kcal. TEE was 111.7 ± 38.5 kcal. When controlling for bodyweight, TEE was 1.5 ± 0.3 kcal/kg. CONCLUSIONS: The results of this study suggest rope training is an extremely vigorous workout, resulting in very high heart rates and caloric expenditure per unit of time. Although rope training provides a potent anaerobic stimulus, the intensity required does not lend itself to maintain the workout for prolonged durations, which may not prove useful for weight loss goals.