Effects of resistance exercise bouts of different intensities but equal work on EPOC

Methods to Assess Energy Expenditure of Resistance Exercise: A Systematic Scoping Review

BACKGROUND

Nutrition guidance for athletes must consider a range of variables to effectively support individuals in meeting energy and nutrient needs. Resistance exercise is a widely adopted training method in athlete preparation and rehabilitation and therefore is one such variable that will influence nutrition guidance. Given its prominence, the capacity to meaningfully quantify resistance exercise energy expenditure will assist practitioners and researchers in providing nutrition guidance. However, the significant contribution of anaerobic metabolism makes quantifying energy expenditure of resistance exercise challenging.

OBJECTIVE

The aim of this scoping review was to investigate the methods used to assess resistance exercise energy expenditure.

METHODS

A literature search of Medline, SPORTDiscus, CINAHL and Web of Science identified studies that included an assessment of resistance exercise energy expenditure. Quality appraisal of included studies was performed using the Rosendal Scale.

RESULTS

A total of 19,867 studies were identified, with 166 included after screening. Methods to assess energy expenditure included indirect calorimetry (n = 136), blood lactate analysis (n = 25), wearable monitors (n = 31) and metabolic equivalents (n = 4). Post-exercise energy expenditure was measured in 76 studies. The reported energy expenditure values varied widely between studies.

CONCLUSIONS

Indirect calorimetry is widely used to estimate energy expenditure. However, given its limitations in quantifying glycolytic contribution, indirect calorimetry during and immediately following exercise combined with measures of blood lactate are likely required to better quantify total energy expenditure. Due to the cumbersome equipment and technical expertise required, though, along with the physical restrictions the equipment places on participants performing particular resistance exercises, indirect calorimetry is likely impractical for use outside of the laboratory setting, where metabolic equivalents may be a more appropriate method.

Low-Load and High-Load Resistance Exercise Completed to Volitional Fatigue Induce Increases in Postexercise Metabolic Responses With More Prolonged Responses With the Low-Load Protocol

ABSTRACT

Grisebach, D, Bornath, DPD, McCarthy, SF, Jarosz, C, and Hazell, TJ. Low-load and high-load resistance exercise completed to volitional fatigue induce increases in post-exercise metabolic responses with more prolonged responses with the low-load protocol. J Strength Cond Res 38(8): 1386-1393, 2024-Comparisons of high-load with low-load resistance training (RT) exercise have demonstrated no differences in postexercise metabolism when volume is matched. This important limitation of matching or equating volume diminishes benefits of the low-load RT protocol. Therefore, the purpose of this study was to determine the effects of acute low-load high volume and high-load low volume RT protocols completed to volitional fatigue on postexercise metabolism. Eleven recreationally active resistance-trained male subjects (24 ± 2 years; BMI: 25.3 ± 1.5 kg·m -2 ) completed 3 experimental sessions: (a) no-exercise control (CTRL); (b) RT at 30% 1 repetition maximum (1RM; 30% 1RM); and (c) RT at 90% 1RM (90% 1RM) with oxygen consumption (V̇ o2 ) measurements 2 hours postexercise. The RT sessions consisted of 3 sets of back squats, bench press, straight-leg deadlift, military press, and bent-over rows to volitional fatigue completed sequentially with 90 seconds of rest between sets and exercises. Changes were considered important if p < 0.100 with a ≥medium effect size. V̇ o2 1 hour postexercise was elevated following 30% 1RM (25%; p = 0.003, d = 1.40) and 90% 1RM (14%; p = 0.010, d = 1.15) vs. CTRL and remained elevated 2 hours postexercise following 30% 1RM (16%; p = 0.010, d = 1.15) vs. CTRL. Total O 2 consumed postexercise increased following 30% 1RM and 90% 1RM (∼17%; p < 0.044, d > 0.91) vs. CTRL. Fat oxidation was elevated 1 hour postexercise following 30% 1RM and 90% 1RM (∼155%; p < 0.001, d > 2.97) and remained elevated 2 hours postexercise following 30% 1RM compared with CTRL and 90% 1RM (∼69%; p < 0.030, d > 1.03). These data demonstrate beneficial changes to postexercise metabolism following high- and low-load RT sessions, with more prolonged effects following the low-load RT protocol completed to volitional fatigue.

Effects of Isocaloric Resistance, Aerobic, and Concurrent Exercise on Excess Postexercise Oxygen Consumption in Older Adults

ABSTRACT

Pilon, R, Matos-Santos, L, Matlez, MP, Rodrigues, G, Amorim, F, Lattari, E, Farinatti, P, and Monteiro, W. Effects of isocaloric resistance, aerobic, and concurrent exercise on excess postexercise oxygen consumption in older adults. J Strength Cond Res 38(4): 755-761, 2024-Excess postexercise oxygen consumption (EPOC) is a major determinant of exercise-related caloric expenditure and metabolic adaptations. Exercise modality may influence the EPOC, but this issue has not been investigated in older adults. This study compared the EPOC after isocaloric bouts of continuous aerobic exercise (AE), resistance exercise (RE), and concurrent exercise (CE) in older individuals. Ten subjects (5 men; 73 ± 6 years) had their cardiorespiratory data assessed during AE, RE, and CE and along 30-minute postexercise recovery. Total energy expenditure (EE) during exercise was similar (p > 0.05) in AE (126.0 ± 30.7 kcal), RE (123.9 ± 30.6 kcal), and CE (130.8 ± 32.6 kcal), with different times to achieve the targeted EE (RE: 61.4 ± 1.9 minutes > CE: 43.3 ± 5.6 minutes > AE: 26.6 ± 5.7 minutes; p < 0.001). Consistently, the relative intensity during exercise was superior (p < 0.05) in AE (74 ± 15% oxygen uptake reserve [VO2R]) vs. CE (43 ± 13% VO2R) vs. RE (24 ± 9% VO2R). Despite the isocaloric conditions, average EPOC and EE were approximately 45% greater (p < 0.001) in AE (8.0 ± 2.3 L; 40.1 ± 11.7 kcal) vs. RE (5.6 ± 1.2 L; 28.1 ± 5.8 kcal) and CE (5.4 ± 2.3 L; 26.9 ± 11.5 kcal). In conclusion, the EPOC was greater after isocaloric AE vs. RE and CE performed by older adults. Exercise intensity seemed to be a more important determinant of EPOC than volume reflected by EE during exercise bouts. Moderate-intensity continuous AE was more time-efficient than RE and CE to achieve a target EE. In older individuals, AE should be preferred over RE or CE when the purpose is to increase the daily caloric expenditure.

Effects of post-exercise intake of exogenous lactate on energy substrate utilization at rest

PURPOSE

This study investigated the effects of exogenous lactate intake on energy metabolism during 1 h of rest after acute exercise.

METHODS

Eight-week-old ICR mice were randomly divided into four groups: SED (no treatment), EXE (exercise only), LAC (post-exercise oral lactate administration), and SAL (post-exercise saline administration) (n=8 per group). The exercise intensity was at VO2max 80% at 25 m/min and 15° slope for 50 min. After acute exercise, the LAC and SAL groups ingested lactate and saline orally, respectively, and were allowed to rest in a chamber. Energy metabolism was measured for 1 h during the resting period.

RESULTS

LAC and SAL group mice ingested lactate and saline, respectively, after exercise and the blood lactate concentration was measured 1 h later through tail blood sampling. Blood lactate concentration was not significantly different between the two groups. Energy metabolism measurements under stable conditions revealed that the respiratory exchange ratio in the LAC group was significantly lower than that in the SAL group. Additionally, carbohydrate oxidation in the LAC group was significantly lower than that in the SAL group at 10-25 min. No significant difference was observed in the fat oxidation level between the two groups.

CONCLUSION

We found that post-exercise lactate intake modified the respiratory exchange ratio after 1 h of rest. In addition, acute lactate ingestion inhibits carbohydrate oxidation during the post-exercise recovery period.

Assessment of Cardiorespiratory and Metabolic Contributions in an Extreme Intensity CrossFit® Benchmark Workout

Our purpose was to characterize the oxygen uptake kinetics (VO2), energy systems contributions and total energy expenditure during a CrossFit® benchmark workout performed in the extreme intensity domain. Fourteen highly trained male CrossFitters, aged 28.3 ± 5.4 years, with height 177.8 ± 9.4 cm, body mass 87.9 ± 10.5 kg and 5.6 ± 1.8 years of training experience, performed the Isabel workout at maximal exertion. Cardiorespiratory variables were measured at baseline, during exercise and the recovery period, with blood lactate and glucose concentrations, including the ratings of perceived exertion, measured pre- and post-workout. The Isabel workout was 117 ± 10 s in duration and the VO2 peak was 47.2 ± 4.7 mL·kg-1·min-1, the primary component amplitude was 42.0 ± 6.0 mL·kg-1·min-1, the time delay was 4.3 ± 2.2 s and the time constant was 14.2 ± 6.0 s. The accumulated VO2 (0.6 ± 0.1 vs. 4.8 ± 1.0 L·min-1) value post-workout increased substantially when compared to baseline. Oxidative phosphorylation (40%), glycolytic (45%) and phosphagen (15%) pathways contributed to the 245 ± 25 kJ total energy expenditure. Despite the short ~2 min duration of the Isabel workout, the oxygen-dependent and oxygen-independent metabolism energy contributions to the total metabolic energy release were similar. The CrossFit® Isabel requires maximal effort and the pattern of physiological demands identifies this as a highly intensive and effective workout for developing fitness and conditioning for sports.

The Acute Effect of High-Intensity Resistance Training on Subsequent Firefighter Performance

ABSTRACT

Mason, MR, Heebner, NR, Abt, JP, Bergstrom, HC, Shapiro, R, Langford, EL, and Abel, MG. The acute effect of high-intensity resistance training on subsequent firefighter performance. J Strength Cond Res 37(7): 1507-1514, 2023-High-intensity resistance training (HIRT) is commonly performed by structural firefighters on duty to enhance occupational readiness. However, exercise-induced fatigue may negatively impact subsequent occupational performance. Therefore, the purpose of this study was to assess the acute effect of HIRT on subsequent occupational physical ability in structural firefighters and to determine the time course of recovery. Seven resistance-trained male firefighters performed a timed maximal effort simulated fireground test (SFGT) in 3 randomized conditions: baseline (SFGT baseline ), 10 minutes post HIRT (SFGT 10min ), and 60 minutes post HIRT (SFGT 60min ). Work efficiency and air depletion were assessed during the SFGT. The timed HIRT session consisted of a standardized set of exercises using absolute training loads. Repeated measures analysis of variance and minimal difference (MD) analysis assessed group and individual effects between the conditions, respectively. The level of significance was set at p < 0.05. SFGT 10min completion time was greater than SFGT baseline (430 ± 137 vs. 297 ± 69 seconds, p < 0.01), with no difference between SFGT baseline and SFGT 60min (297 ± 69 vs. 326 ± 89 seconds, p = 0.08). The MD analysis indicated that all firefighters' SFGT 10min times exceeded the MD (±26.4 seconds) compared with SFGT baseline . However, 43% of firefighters still exceeded the MD at SFGT 60min . Air depletion during SFGT 10min was greater than that during SFGT baseline (2,786 ± 488 vs. 2,186 ± 276 lb·in -2 , p = 0.02), with no difference between SFGT baseline and SFGT 60min ( p = 0.25). Work efficiency during SFGT 10min was 40% lower than that during SFGT baseline ( p < 0.01), with no difference between SFGT baseline and SFGT 60min ( p = 0.25). These findings indicate that an acute bout of HIRT decreases multiple descriptors of firefighters' occupational performance 10 minutes post exercise with varied responses at 60 minutes post exercise.

Effects of acute resistance exercise with different loads on appetite, appetite hormones and autonomic nervous system responses in healthy young men

Although the effect of continuous aerobic exercise on the appetite has been widely explored, the influence of resistance exercise (RE) with different variables, including training loads, training volume, and inter-set rest, on appetite responses requires further investigation. This study examined the importance of training load in RE-induced appetite regulation, with the total training volume and inter-set rest equalized. In total, 11 healthy young men (age = 23 ± 2 years, body mass index = 22 ± 2 kg/m²) were included. Participants completed 3 trials, namely moderate-load RE (MOD; 4 sets of 8 repetitions at 85% 8RM), low-load RE (LOW; 4 sets of 15 repetitions at 45% 8RM), and a control (CON; no exercise), in a randomized, crossover design. Subjective appetite ratings; concentrations of ghrelin, peptide YY (PYY), and lactate; and the autonomic nervous system activity were evaluated before exercise and 1 h after exercise. The hunger and predicted food consumption ratings, and ghrelin concentrations immediately after exercise were significantly lower in the MOD and LOW trials (p < 0.05 vs. CON). The PYY and lactate concentrations immediately after exercise were significantly higher in the MOD and LOW trials (p < 0.05 vs. CON). Heart rate variability recovery was slower in the MOD trial. These findings suggest that both moderate-load and low-load RE at equal training volumes and inter-set rest induce similar responses on hunger suppression and orexigenic signals, except for the slower recovery of autonomic modulation after moderate-load RE. Our results suggest that when individuals aim to potentiate appetite suppression after a bout of RE, both moderate- and low-load RE could be applied.

THE EFFECT OF HIGH-INTENSITY INTERVAL TRAINING ON POST-EXERCISE OXYGEN CONSUMPTION: A META-ANALYSIS

ABSTRACT Introduction: The objective of this study was to present a systematic review and meta-analysis to compare total excess post-exercise oxygen consumption (EPOC) for two training intervention models in healthy individuals, and the secondary objective was to understand whether oxygen consumption after exercise could really promote a meaningful help. Design: To design a meta-analysis review to compare two training intervention models (experimental: high-intensity interval training; and control: continuous moderate-intensity) and their effects on total EPOC in healthy individuals. Participants: Seventeen studies were considered to be of good methodological quality and with a low risk of bias. Methods: Literature searches were performed using the electronic databases with no restriction on year of publication. The keywords used were obtained by consulting Mesh Terms (PubMed) and DeCS (BIREME Health Science Descriptors). Results: The present study findings showed a tendency (random-effects model: 0.87, 95%-CI [0.35,1.38], I2=73%, p<0.01) to increase EPOC when measured following high-intensity interval training. Conclusions: Our study focused on the analysis of high- and moderate-intensity oxygen uptake results following exercise. Despite the growing popularity of high-intensity interval training, we found that the acute and chronic benefits remain limited. We understand that the lack of a standard protocol and standard training variables provides limited consensus to determine the magnitude of the EPOC. We suggest that longitudinal experimental studies may provide more robust conclusions. Another confounding factor in the studies investigated was the magnitude (time in minutes) of VO2 measurements when assessing EPOC. Measurement times ranged from 60 min to 720 min. Longitudinal studies and controlled experimental designs would facilitate more precise measurements and correct subject numbers would provide accurate effect sizes. Systematic reviewb of Level II studies.

Acute circulatory and femoral hemodynamic responses induced by standing core exercise at different rotational cadence: a crossover study

Background

Core exercise is often adopted as an adjunct in maintaining musculoskeletal health in rehabilitation; we previously showed that standing core rotational exercise improves femoral blood flow after training. This study aimed to investigate the effects of different rotational cadences on circulatory and hemodynamic responses after acute standing core exercise.

Methods

Sixteen healthy male adults (22 ± 1 yrs) were randomly assigned to participate in two 30-min standing core exercises of fast (75 rpm, FC) and slow cadence (20 rpm, SC) sessions after completing an acute bout of seated knee extension exercise session (KE) (80% of 1 repetition maximum × 12 repetitions × 3 sets). Impedance cardiography-derived circulatory responses and femoral hemodynamics by ultrasound imaging were measured pre- and 30, and 60 min post-exercise.

Results

KE acutely increased post-exercise cardiac output at 30 min (p = 0.008) and heart rate at 30 min (p = 0.04) and 60 min (p = 0.01), yet brachial blood pressure did not change. Systemic vascular resistance was significantly lower after FC and KE at 30 min (p = 0.008) and 60 (p = 0.04) min, respectively, compared with the baseline. In addition, KE acutely decreased post-exercise arterial stiffness (p = 0.05) at 30 min, increased femoral conductance (p = 0.03, p < 0.001), and blood flow (p = 0.009, p < 0.001) at 30 and 60 min. No significant changes were observed in absolute femoral blood flow after FC and SC, except that FC significantly increased relative femoral blood flow (p = 0.007) and conductance (p = 0.005). Post-exercise femoral diameter significantly increased in KE at 30 (p = 0.03) and 60 min (p = 0.01), but not in core exercise.

Conclusion

Our results suggest that standing core exercise elicits circulatory and hemodynamic changes only when the rotational cadence is set at a faster cadence, which provides preliminary scientific evidence for its use in exercise programs.

Oxygen Consumption (VO2) and Surface Electromyography (sEMG) during Moderate-Strength Training Exercises

Oxygen consumption (VO₂) during strength training can be predicted through surface electromyography (sEMG) of local muscles. This research aimed to determine relations between VO₂ and sEMG of upper and lower body muscles to predict VO₂ from sEMG during moderate-intensity strength training exercises. Of the 12 participants recruited, 11 were divided into two groups: untrained (n = 5; with no training experience) and trained (n = 6; with 2 months of training experience). On different days, each individual completed six training sessions. Each participant performed training sessions consisting of three types of dumbbell exercises: shoulder press, deadlift, and squat, while wearing a mask for indirect calorimetric measurements of VO₂ using the Cortex Metalyzer 3B. sEMG measurements of the bilateral middle deltoid, lumbar erector spinae, quadriceps (rectus femoris), and hamstring (biceps femoris) muscles were recorded. The VO₂ was predicted from sEMG root mean square (RMS) values of the investigated muscles during the exercise period using generalized estimating equation (GEE) modeling. The predicted models for the three types of exercises for the untrained vs. trained groups were shoulder press [QIC = 102, * p = 0.000 vs. QIC = 82, * p = 0.000], deadlift [QIC = 172, * p = 0.000 vs. QIC = 320, * p = 0.026], and squat [QIC = 76, * p = 0.000 vs. QIC = 348, * p = 0.001], respectively. It was observed that untrained vs. trained groups predicted GEE models [quasi-likelihood under an independence model criterion (QIC) = 368, p = 0.330 vs. QIC = 837, p = 0.058], respectively. The study obtained significant VO₂ prediction models during shoulder press, deadlift, and squat exercises using the right and left middle deltoid, right and left lumbar erector spinae, left rectus femoris, and right and left biceps femoris sEMG RMS for the untrained and trained groups during moderate-intensity strength training exercises.

Acute Behavior of Oxygen Consumption, Lactate Concentrations, and Energy Expenditure During Resistance Training: Comparisons Among Three Intensities

Purpose: This study aimed to compare the oxygen consumption, lactate concentrations, and energy expenditure using three different intensities during the resistance training sessions.

Methods: A total of 15 men (22.9 ± 2.61 years) experienced in resistance training underwent 3 sessions composed of 8 exercises (chest press, pec deck, squat, lat pull-down, biceps curl, triceps extension, hamstring curl, and crunch machine), which were applied in the same order. The weight lifted differed among the sessions [high session: 6 sets of 5 repetitions at 90% of 1-repetition maximum (1-RM); intermediary session: 3 sets of 10 repetitions at 75% of 1-RM; and low session: 2 sets of 15 repetitions at 60% of 1-RM]. The oxygen consumption (VO₂)—during and after (excess post-exercise oxygen consumption (EPOC)) the session, blood lactate concentration, and energy expenditure (i.e., the sum of aerobic and anaerobic contributions, respectively) were assessed.

Results: The VO2 significantly decreased in the function of the weight lifting (F_(2.28) = 17.02; p < 0.01; ηG2 = 0.32). However, the aerobic contributions significantly increase in the function of the weight lifting (F_(2.28) = 79.18; p < 0.01; ηG2 = 0.75). The anaerobic contributions were not different among the sessions (p > 0.05; ηG2 < 0.01). Thus, the total energy expenditure during the session (kcal) significantly increased in the function of the weight lifting (F_(2.28) = 86.68; p < 0.01; ηG2 = 0.75). The energy expenditure expressed in time unit (kcal·min⁻¹) was higher in low session than in high session (F_(2.28) = 6.20; p < 0.01; ηG2 = 0.15).

Conclusion: The weight lifted during resistance training-induced different physiological responses, which induced higher energy expenditure per unit of time during the low session.

The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis

BACKGROUND

Resistance training is the gold standard exercise mode for accrual of lean muscle mass, but the isolated effect of resistance training on body fat is unknown.

OBJECTIVES

This systematic review and meta-analysis evaluated resistance training for body composition outcomes in healthy adults. Our primary outcome was body fat percentage; secondary outcomes were body fat mass and visceral fat.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

We searched five electronic databases up to January 2021.

ELIGIBILITY CRITERIA

We included randomised trials that compared full-body resistance training for at least 4 weeks to no-exercise control in healthy adults.

ANALYSIS

We assessed study quality with the TESTEX tool and conducted a random-effects meta-analysis, with a subgroup analysis based on measurement type (scan or non-scan) and sex (male or female), and a meta-regression for volume of resistance training and training components.

RESULTS

From 11,981 records, we included 58 studies in the review, with 54 providing data for a meta-analysis. Mean study quality was 9/15 (range 6-15). Compared to the control, resistance training reduced body fat percentage by - 1.46% (95% confidence interval - 1.78 to - 1.14, p < 0.0001), body fat mass by - 0.55 kg (95% confidence interval - 0.75 to - 0.34, p < 0.0001) and visceral fat by a standardised mean difference of - 0.49 (95% confidence interval - 0.87 to - 0.11, p = 0.0114). Measurement type was a significant moderator in body fat percentage and body fat mass, but sex was not. Training volume and training components were not associated with effect size. Resistance training reduces body fat percentage, body fat mass and visceral fat in healthy adults.

STUDY REGISTRATION

osf.io/hsk32.

The Effect of High Volume Power Training on Repeated High-Intensity Performance and the Assessment of Repeat Power Ability: A Systematic Review

BACKGROUND

High volume power training (HVPT) involves high volumes of high-velocity resistance training, with the aim to improve repeated high-intensity efforts (RHIEs). Repeat power ability (RPA) is the ability to repeatedly produce maximal or near maximal efforts. Assessments of RPA using external loading may determine the ability to perform repeat RHIEs typical of many sports and, therefore, provide useful information on the effectiveness of training.

OBJECTIVES

(1) Identify the different HVPT protocols; (2) examine the acute responses and chronic adaptations to different HVPT protocols; (3) identify different lower body RPA assessment protocols and highlight similarities, differences and potential limitations between each protocol, and; (4) describe the reliability and validity of RPA assessments.

METHODS

An electronic search was performed using SPORTDiscus, PubMed, CINAHL and Embase for studies utilising HVPT protocols and assessments of RPA. Eligible studies included peer-reviewed journal articles published in English.

RESULTS

Twenty studies met the inclusion criteria of the final review. Of the eight longitudinal studies, three were rated as fair and five were rated as poor methodological quality, respectively. In contrast, all 12 cross-sectional studies were considered to have a low risk of bias. Preliminary evidence suggests that HVPT can enhance RHIE, RPA, anaerobic capacity, anaerobic power and aerobic performance. HVPT generally consists of 2-3 sessions per week, utilising loads of 30-40% 1 repetition maximum (RM), for 3-5 sets of 10-20 repetitions, with inter-set rest periods of 2-3 min. RPA assessments can be valid and reliable and may provide useful information on an athlete's ability to perform RHIE and the success of HVPT programmes.

CONCLUSIONS

HVPT can be used to improve a number of physical qualities including RPA and RHIE; while a variety of RPA assessments provide valid and reliable information regarding the athlete's ability to perform RHIEs. Considering the heterogeneity in the HVPT protocols currently used and the relatively low volume and quality of longitudinal publications in this area, further studies are needed to identify the effects of a variety of HVPT methods on RPA, RHIE and other performance outcomes and to identify the most valid and reliable RPA outcomes to use in such studies.

DOES THE NUMBER OF JOINTS INVOLVED IN EXERCISE PROMOTE CHANGES IN ENERGY EXPENDITURE?

ABSTRACT Introduction: The benefits of strength training (ST) include not only strength improvement but also favorable body composition changes, which has led to a considerable increase in the indication of this training method in overweight and obese individuals, and has made the investigation of outcomes attributed to different manipulations of ST variables an important task. However, acute metabolic responses related to energy expenditure (EE) associated with the manipulation of exercises which, in turn, are associated with the number of joints involved in movement, are still inconclusive. Objective: To verify the influence of the number of joints involved in movement on EE with equalized volume in ST at different intensities. Methods: This training program was held on alternate days, with a 48-hour interval between each session, and with two randomized protocols, as follows: multi joint protocol with four common exercises for ST participants compared to the single joint protocol with four exercises. Each protocol was evaluated at three training intensities (90%, 75% and 60% of 1-RM) according to the one-repetition maximum test. Results: Significant increases in EE were observed in the multi joint session as compared to the single joint session: 90% 1-RM multi joint 246.80 ± 26.17 kcal vs single joint 227.40 ± 24.54 kcal (∆ -7.86, 95% CI 7.33; 31.46; t 3.44; p <0.05); 75% 1-RM multi joint 124.13 ± 25.40 kcal vs single joint 111.80 ± 22.78 kcal (∆ -9.93, 95% CI 3.25; 21.41; t 2.91; p <0.05); 60% 1-RM multi joint 70.80 ± 6.28 kcal vs single joint 64.40 ± 6.72 kcal (∆-9.04, 95% CI 3.95; 8.84; t 5.60; p <0.05). Conclusion: Multi joint exercises may be a variable to consider when EE balance is the main target of the ST program. However, further studies are needed to supplement our findings. Level of evidence II; Diagnostic studies-Investigating a diagnostic test.

Does Oxygen Uptake Before Physical Exercise Affect Tear Osmolarity?

Recently, it has been reported that tear osmolarity (Tosm) is correlated with plasma osmolarity and will increase during exertion. We aimed to assess whether inhaling oxygen-enriched air between exercises could significantly change the Tosm value. Thirty men aged 24.9 years were included in the study. A cycloergometer was used to perform the exercise protocol. We recorded the participants’ Tosm (mOsm/L), heart rate (HR, beats/minute), oxygen saturation, and blood pressure values. After the first exhaustive exercise (T1), participants inhaled oxygen in the experimental group and a placebo in the control group. After the second exercise (T2), another set of measurements was obtained. The Tosm value before exercise was 297.4 ± 1.21 and 296.53 ± 1.11 mOsm/L (p = 0.61718) and the HR was 72.6 ± 2.59 and 73 ± 2.59 beats/minute (p = 0.39949) in the study and the control group, respectively. At T1, Tosm was 303.67 ± 1.25 and 302.2 ± 1.25 mOsm/L (p = 0.41286) and the HR reached 178.04 ± 2.60 and 176.4 ± 2.60 beats/minute (p = 0.65832), respectively. At T2, Tosm in the study group reached 305.73 ± 0.86 mOsm/L (correlation with the use of oxygen: r = −0.3818), and in the control group, it was 308.4 ± 0.86 mOsm/L (p = 0.0373), while the HR reached 172.20 ± 2.53 beats/minute in the study group and 178.2 ± 2.53 beats/minute in the control group (p = 0.057). It was concluded that inhaling oxygen before and after exercise could increase the rate of recovery after exhaustive exercise.

Acute low- compared to high-load resistance training to failure results in greater energy expenditure during exercise in healthy young men

The objective of the present study was to verify the energy expenditure (EE), energy system contributions and autonomic control during and after an acute low-load or high-load resistance training (RT) protocol to momentary failure (MF) in young adults. Eleven young men (22 ± 3 yrs, 71.8 ± 7.7 kg; 1.75 ± 0.06 m) underwent a randomized crossover design of three knee extension acute protocols: a low-load RT [30% of their maximal strength (1RM); RT30] or a high-load RT (80% of 1RM; RT80) protocol, with all sets being performed to MF; or a control session (Control) without exercise. Participants were measured for EE, energy system contributions, and cardiac autonomic control before, during, and after each exercise session. Exercise EE was significantly higher for RT30 as compared to RT80. Furthermore, post measurements of blood lactate levels and the anaerobic lactic system contribution were significantly greater for RT30 as compared to RT80. In addition, parasympathetic restoration was lower for RT30 as compared to RT80. In conclusion, a low-load (30% 1RM) RT session produced higher EE during exercise than a high-load (80% 1RM) RT session to MF, and may be a good option for fitness professionals, exercise physiologists, and practitioners when choosing the optimal RT protocol that provides more EE, especially for those who want or need to lose weight.

Energy expenditure, recovery oxygen consumption, and substrate oxidation during and after body weight resistance exercise with slow movement compared to treadmill walking

The benefit of body weight resistance exercise with slow movement (BWRE-slow) for muscle function is well-documented, but not for energy metabolism. We aimed to examine physiological responses [e.g., energy expenditure (EE), respiratory exchange ratio (RER), and blood lactate (La)] during and after BWRE-slow compared to EE-matched treadmill walking (TW). Eight healthy young men (23.4 ± 1.8 years old, 171.2 ± 6.2 cm, 63.0 ± 4.8 kg) performed squat, push-up, lunge, heel-raise, hip-lift, and crunch exercises with BWRE-slow modality. Both the concentric and eccentric phases were set to 3 s. A total of three sets (10 repetitions) with 30 s rest between sets were performed for each exercise (26.5 min). On another day, subjects walked on a treadmill for 26.5 min during which EE during exercise was matched to that of BWRE-slow with the researcher controlling the treadmill speed manually. The time course changes of EE and RER were measured. The EE during exercise for BWRE-slow (92.6 ± 16.0 kcal for 26.5 min) was not significantly different from the EE during exercise for TW (95.5 ± 14.1 kcal, p = 0.36). BWRE-slow elicited greater recovery EE (40.55 ± 3.88 kcal for 30 min) than TW (37.61 ± 3.19 kcal, p = 0.029). RER was significantly higher in BWRE-slow during and 0-5 min after exercise, but became significantly lower during 25-30 min after exercise, suggesting greater lipid oxidation was induced about 30 min after exercise in BWRE-slow compared to TW. We also indicated that BWRE-slow has 3.1 metabolic equivalents in average, which is categorized as moderate-intensity physical activity.

COMPARISON OF EPOC AND RECOVERY ENERGY EXPENDITURE BETWEEN HIIT AND CONTINUOUS AEROBIC EXERCISE TRAINING

ABSTRACT Objectives: The objective of this study was to compare EPOC - excess post-exercise oxygen consumption and recovery energy expenditure between high intensity interval aerobic exercise (HIIT) and continuous aerobic exercise in adult amateur runners. Methods: The study included 10 runners, with a mean age of 35.7 ± 5.87 years, height 1.69 ± 0.11 m; body mass 74.13 ± 11.26 kg; fat percentage 19.31 ± 4.27% and maximal oxygen consumption (VO2max) of 3.50 ± 0.64 l/kg/min-1. The continuous aerobic exercise protocol consisted of 20 minutes of running with intensity of 70-75% HRmax. Two 20-second cycles of 8 sprints were performed for HIIT at the highest possible speed, with 10 seconds of rest and a 3-minute interval between cycles. The sample group performed the two protocols at least 48 hours and at most one week apart. EPOC was observed using ergospirometry after the running protocols, and mean consumption was analyzed between 25-30 minutes after exercise. Oxygen consumption at 9-10 minutes was used for resting consumption. The study has a cross-sectional experimental design. Results: Oxygen consumption of 0.57 ± 0.29l/kg/min1 and energy expenditure of 2.84 ± 1.44 kcal/min were observed for continuous aerobic exercise, with values of 0.61 ± 0.62 l/kg/min−1 and 3.06 ± 1.10 kcal/min respectively (p <0.05) for HIIT. Conclusion: The protocols performed did not show a statistically significant difference in terms of EPOC and energy expenditure, but the performance of HIIT increased lipid metabolism for exercise recovery, which may favor the weight loss process. Moreover, this activity model takes up less time. Level of evidence I, randomized clinical trial.

OXYGEN CONSUMPTION AND ENERGY EXPENDITURE DURING AND AFTER STREET GAMES, ACTIVE VIDEO GAMES AND TV

ABSTRACT Introduction: Physical activity has become less frequent since the 1980s, even among more active children. Objective: To analyze excess post-exercise oxygen consumption (EPOC) and total energy expenditure (TEE) in children during and after three different activities. Methods: Sixteen healthy children (9.6±0.1 yrs.) randomly underwent the following procedures lasting 30 minutes on different days: (a) traditional games (PLAY), (b) active video game (Dance Dance Revolution; DDR), and (c) watching television (TV). Oxygen consumption (VO2) was measured at rest, at the 10th, 20th, and 30th minute of intervention, and for 40 minutes post-intervention. TEE was also measured. Results: At the end of intervention, VO2 had increased by 330% and 166% for PLAY and DDR, respectively, compared to the rest. EPOC in PLAY was seen to occur at the 10th, 20th, and 30th post-interventional minutes from 7.00±1.02 (at rest) to 10.83±0.94, 10.03±0.58, and 9.80±0.77mL.kg-1.min-1, respectively. However, EPOC in DDR occurred at only the 10th postinterventional minute (7.04 to 8.61 mL.kg-1.min-1; p<0.01). After intervention, TEE in PLAY was greater than in DDR and TV (112.08±19.45 vs 56.98±6.34 vs 36.39±4.5 kcal; p<0.01), respectively. Conclusions: PLAY induced children to reach a greater VO2 during activity and greater EPOC and TEE compared to DDR and TV. Level of evidence A1b; Crossover study.

High-Intensity Intermittent Exercise Increases Fat Oxidation Rate and Reduces Postprandial Triglyceride Concentrations

(1) Background: This study investigated the effect of acute barehanded whole body high-intensity intermittent exercise (HIIE) and moderate intensity and continuous exercise (MICE) at the same quantity of energy expenditure on postprandial triglyceride (TG) concentrations. (2) Methods: Nine healthy males completed three trials (HIIE, MICE and control (CON)) in a random order separated by at least 14 days. After each intervention, the participants rested for 12 h and consumed a high-fat test meal on the next day. The blood samples and respiratory exchange ratio were observed in the fasted state and for 4 h after consuming the test meal. (3) Results: The HIIE had a significantly higher area under the curve of postprandial fat oxidation rate than MICE (p = 0.027) and CON (p = 0.035) and exhibited significantly lower postprandial TG concentration than the MICE and CON at 2 and 4 h after the test meal. Moreover, the HIIE displayed a higher postprandial TG concentration area under the curve than MICE (p = 0.013) and CON (p = 0.048). (4) Conclusions: The present study concluded that acute barehanded whole body HIIE could significantly lower postprandial TG concentrations. It possibly can induce a rise in the postprandial fat oxidation rate.

Acute Cardiorespiratory and Metabolic Effects of a Sandbag Resistance Exercise Protocol

Ratamess, NA, Kang, J, Kuper, JD, O'Grady, EA, Ellis, NL, Vought, IT, Culleton, E, Bush, JA, and Faigenbaum, AD. Acute cardiorespiratory and metabolic effects of a sandbag resistance exercise protocol. J Strength Cond Res 32(6): 1491-1502, 2018-The purpose of this study was to examine the acute cardiorespiratory and metabolic effects of a sandbag (SB) resistance exercise protocol and compare the responses to time-matched treadmill running protocols. Eight healthy, resistance-trained men (21.1 ± 1.0 years; 86.1 ± 7.8 kg) completed 4 protocols of equal duration in random sequence: (a) SB, (b) treadmill running at 60% of V[Combining Dot Above]O2 reserve (60V[Combining Dot Above]O2R), (c) treadmill running at 80% of V[Combining Dot Above]O2 reserve (80V[Combining Dot Above]O2R), and (d) a control protocol. The SB protocol was 16 minutes in duration and consisted of 3 circuits of 8 multiple-joint exercises (with 11-, 20-, or 48-kg SBs) performed for as many repetitions as possible for 20 seconds followed by a 10-second rest interval before beginning the next exercise. Two minutes of rest was allowed between circuits. Breath-by-breath oxygen consumption (V[Combining Dot Above]O2) and heart rate (HR) were recorded throughout each protocol and for 30 minutes postexercise (PE) and blood lactate was determined before and immediately after each protocol. Blood lactate was significantly higher after SB compared with 60V[Combining Dot Above]O2R and 80V[Combining Dot Above]O2R. Mean and peak HR in SB was significantly higher than 60V[Combining Dot Above]O2R but not different from 80V[Combining Dot Above]O2R. Mean V[Combining Dot Above]O2 and energy expenditure (EE) in SB was significantly lower than 60V[Combining Dot Above]O2R and 80V[Combining Dot Above]O2R during each protocol but significantly higher after SB compared with 60V[Combining Dot Above]O2R and 80V[Combining Dot Above]O2R PE. Compared with 60V[Combining Dot Above]O2R and 80V[Combining Dot Above]O2R, respiratory exchange ratio was significantly higher during SB and through 5 minutes PE, but was significantly lower at 25-30 minutes PE after SB. Sandbag, as performed in this study, provides a superior metabolic stimulus to treadmill running during the PE period; however, the SB results demonstrate inferior EE compared with running at 60V[Combining Dot Above]O2R and 80V[Combining Dot Above]O2R.

p38 MAPK activation and H3K4 trimethylation is decreased by lactate in vitro and high intensity resistance training in human skeletal muscle

Exercise induces adaptation of skeletal muscle by acutely modulating intracellular signaling, gene expression, protein turnover and myogenic activation of skeletal muscle stem cells (Satellite cells, SCs). Lactate (La)-induced metabolic stimulation alone has been shown to modify SC proliferation and differentiation. Although the mechanistic basis remains elusive, it was demonstrated that La affects signaling via p38 mitogen activated protein kinase (p38 MAPK) which might contribute to trimethylation of histone 3 lysine 4 (H3K4me3) known to regulate satellite cell proliferation and differentiation. We investigated the effects of La on p38 MAPK and H3K4me3 in a model of activated SCs. Differentiating C2C12 myoblasts were treated with La (20 mM) and samples analysed using qRT-PCR, immunofluorescence, and western blotting. We determined a reduction of p38 MAPK phosphorylation, decreased H3K4me3 and reduced expression of Myf5, myogenin, and myosin heavy chain (MHC) leading to decreased differentiation of La-treated C2C12 cells after 5 days of repeated La treatment. We further investigated whether this regulatory pathway would be affected in human skeletal muscle by the application of two different resistance exercise regimes (RE) associated with distinct metabolic demands and blood La accumulation. Muscle biopsies were obtained 15, 30 min, 1, 4, and 24 h post exercise after moderate intensity RE (STD) vs. high intensity RE (HIT). Consistent with in vitro results, reduced p38 phosphorylation and blunted H3K4me3 were also observed upon metabolically demanding HIT RE in human skeletal muscle. Our data provide evidence that La-accumulation acutely affects p38 MAPK signaling, gene expression and thereby cell differentiation and adaptation in vitro, and likely in vivo.

Supersets do not change energy expenditure during strength training sessions in physically active individuals

Background/Objective

The energy expenditure (EE) in strength training (ST) is analyzed both during and after each training session. However, little information exists about the influence of strength exercises supersets on EE. We aimed to determine whether supersets of ST exercises influenced EE during and after one strength exercise session.

Methods

Twenty men were randomly divided to perform either a session with grouped exercises for the same muscle (GE: 26.6 ± 3.4 years; 17.4 ± 3.4 body fat) or a session with separated exercises (SE: 24.9 ± 2.6 years; 15.4 ± 5.9 body fat). Four exercises (5 sets of 8-10 maximum repetitions) for knee extensor muscles and shoulder horizontal flexor muscles were executed in both training sessions. The EE of each experimental session was obtained through the analysis of oxygen uptake during and after exercise (60 minutes postsession).

Results

Total work during the session and increases in lactate concentrations were similar between the GE and SE Groups. During exercise, EE was greater in the SE Group when compared with the GE Group (GE: 123.8 ± 14.36 kcal vs. SE: 131.77 ± 20.91 kcal). During the postexercise period, GE induced greater EE when compared with SE (GE: 25.12 ± 7.86 kcal vs. SE: 19.76 ± 5.53 kcal). However, the exercise sequence did not influence overall EE (GE: 148.92 ± 18.72 kcal vs. SE: 151.53 ± 17.97 kcal, p = 0.920).

Conclusion

Our findings indicate that, in physically active men, ST supersets do not influence total EE during and 60 minutes after a single session.

Weight training, aerobic physical activities, and long-term waist circumference change in men

OBJECTIVE

Findings on weight training and waist circumference (WC) change are controversial. This study examined prospectively whether weight training, moderate to vigorous aerobic activity (MVAA), and replacement of one activity for another were associated with favorable changes in WC and body weight (BW).

METHODS

Physical activity, WC, and BW were reported in 1996 and 2008 in a cohort of 10,500 healthy U.S. men in the Health Professionals Follow-up Study. Multiple linear regression models (partition/substitution) to assess these associations were used.

RESULTS

After adjusting for potential confounders, a significant inverse dose-response relationship between weight training and WC change (P-trend <0.001) was observed. Less age-associated WC increase was seen with a 20-min/day activity increase; this benefit was significantly stronger for weight training (-0.67 cm, 95% CI -0.93, -0.41) than for MVAA (-0.33 cm, 95% CI -0.40, -0.27), other activities (-0.16 cm, 95% CI -0.28, -0.03), or TV watching (0.08 cm, 95% CI 0.05, 0.12). Substituting 20 min/day of weight training for any other discretionary activity had the strongest inverse association with WC change. MVAA had the strongest inverse association with BW change (-0.23 kg, 95% CI -0.29, -0.17).

CONCLUSIONS

Among various activities, weight training had the strongest association with less WC increase. Studies on frequency/volume of weight training and WC change are warranted.

Mechanical load and physiological responses of four different resistance training methods in bench press exercise

The purpose of the study was to compare the mechanical impact and the corresponding physiological responses of 4 different and often practically applied resistance training methods (RTMs). Ten healthy male subjects (27.3 ± 3.2 years) experienced in resistance training performed 1 exhausting set of bench press exercise until exhaustion for each of the following RTMs: strength endurance (SE), fast force endurance (FFE), hypertrophy (HYP), and maximum strength (MAX). The RTMs were defined by different lifting masses and different temporal distributions of the contraction modes per repetition. Mean concentric power (P), total concentric work (W), and exercise time (EXTIME) were determined. Oxygen uptake (V[Combining Dot Above]O2) was measured during exercise and for 30 minutes postexercise. Mean V[Combining Dot Above]O2, volume of consumed O2, and excess postexercise oxygen consumption (EPOC) were calculated over 30 minutes of recovery. Maximum blood lactate concentration (LAmax) was also determined postexercise. The P was significantly higher (p < 0.01) for FFE and MAX compared with that for SE and HYP. The W was significantly higher for FFE than for all other RTMs (p < 0.01), and it was also lower for SE than for MAX (p < 0.05). EXTIME for SE was significantly higher (p < 0.01) than for all other RTMs, whereas EXTIME for MAX was significantly lower (p < 0.01) than for all other RTMs. Mean V[Combining Dot Above]O2 was significantly higher during FFE than during all other RTMs (p < 0.01). Consumed O2 was significantly higher (p < 0.05) during SE than for HYP and MAX, and it was also significantly higher for FFE and HYP compared with MAX (p < 0.05). The LAmax was significantly higher after FFE than after MAX (p < 0.05). There were no significant differences in EPOC between all RTMs. The results indicate that FFE and MAX are adequate to train muscular power despite the discrepancy in the external load. Because FFE performance achieves the highest amount in mechanical work, it may also elicit the highest total energy expenditure. The FFE challenges aerobic metabolism most and SE enables the longest EXTIME, indicating both are appropriate to enhance aerobic muscular capacities. The EPOC and LA values may indicate that energy needs covered by anaerobic metabolism are not higher during HYP and MAX compared with the RTM of lower external load.

Estimativa do equivalente metabólico (MET) de um protocolo de exercícios físicos baseada na calorimetria indireta

OBJETIVO: O objetivo do estudo foi determinar o gasto energético (GE) em termos de gasto calórico e equivalente metabólico (MET) de duas sessões de um protocolo de exercício. MÉTODOS: Quinze indivíduos adultos (51,0 ± 5,5 anos) realizaram as sessões de exercício (80min), compostas por (aquecimento, caminhada e flexibilidade; Sessão A) e (aquecimento, caminhada e resistência muscular local; Sessão B). A frequência cardíaca (FC) foi medida durante cada parte da sessão. Em laboratório, foram medidos, em dias diferentes, o consumo máximo de oxigênio (VO2max), durante repouso e exercício (usando a FC média obtida nas aulas), por calorimetria indireta. O MET dos exercícios foi obtido dividindo VO2 em exercício (mL.kg-¹. min-¹) pelo VO2 em repouso (mL.kg-¹.min-¹). O GE dos exercícios foi calculado por: MET x Peso (kg) x Tempo (min)/60. RESULTADOS: Os resultados foram analisados por ANOVA com teste post hoc de Tukey (p < 0,05). Resultados: Um MET para este grupo foi de 2,7 ± 0.1mL.kg ¹. min-¹. O valor médio de MET nos exercícios foi de 4,7 ± 0,8 (aquecimento), 5,8 ± 0,9 (caminhada) e 3,6 ± 0,7 (flexibilidade) na sessão A, e 4,6 ± 1,2 (aquecimento), 5,6 ± 1,0 (caminhada) e 4,8 ± 1,0 (resistência muscular localizada) na sessão B. O custo de energia foi similar entre as sessões (A: 398 ± 86,7 kcal e B: 404 ± 45 kcal; p > 0,05). Nenhuma atividade foi classificada como vigorosa (> 7 METs). Não houve diferença no VO2 entre caminhada (15,6 ± 2,8 ou 15,4 ± 2,6 mL.kg-¹.min-¹) e resistência muscular localizada (13,2 ± 2,9 mL.kg-¹.min-¹) embora ambos tenham sido superiores (p > 0,05) aos exercícios de flexibilidade (10,1 ± 2,2 mL.kg-¹. min-¹). CONCLUSÃO: O protocolo proposto atinge a atividade física necessária para adultos saudáveis, para melhorar e manter a saúde, por sua estrutura, intensidade moderada, duração, frequência e gasto calórico.

Does aerobic and strength exercise sequence in the same session affect the oxygen uptake during and postexercise?

Concurrent training is a strategy employed in both general fitness and sports conditioning. The purpose of this study was to compare the responses of VO2 in different combinations of strength exercise with aerobic interval exercise. Eight men (23.6 ± 4.2 years, 178 ± 6.3 cm, 77 ± 7.9 kg, 7.67 ± 1.95% body fat) completed 3 combinations of strength training (ST) and aerobic training (AT) in a randomized order with a 7-day recovery period: AT before ST exercises, AT between 2 blocks of ST exercises, and AT after ST exercises. The ST comprised 4 exercises performed in 3 sets of 10 reps and 2 exercises, abdominal crunch and lumbar extension, performed in 3 sets of 30 and 20 reps, respectively. The AT consisted of a 20-minute interval cycling. There were no significant differences in the values of absolute or relative VO2, in the heart rate (HR) and in the respiratory exchange ratio (RER) when the 3 sessions (during + postexercise measurements) were compared (values are mean ± SD). Analyzing only ST in each session, differences were detected in the RER values (F = 4.714; p < 0.05; η2 = 0.308) between AT before ST and AT in the middle of ST (1.01 ± 0.97 vs. 1.11 ± 0.07, respectively). In all sequences, there was a significant increase (p < 0.05) in the values of relative and absolute VO2 and HR, and a significant decrease in RER values (p < 0.05) from the first to the second part of the ST session. The values of absolute or relative VO2, HR, and RER did not vary significantly among the 3 sessions as compared with the AT after ST. These data support the hypothesis that ST and AT, when performed in sequence in the same session, do not seem to affect the overall oxygen consumption during the exercise session. Therefore, training sessions may incorporate both modalities without apparent impact on aerobic exercise.

Consumo de oxigênio de recuperação em resposta a duas sessões de treinamento de força com diferentes intensidades

O objetivo do presente estudo foi comparar o comportamento do consumo de oxigênio (VO2) em resposta a uma sessão de treinamento de força (TF) com objetivo em hipertrofia muscular (HP) com uma sessão com objetivo em resistência muscular localizada (RML). Nove indivíduos do sexo masculino (23,1 ± 2,1 anos) foram recrutados para este estudo. A força muscular dinâmica foi mensurada através do teste de 1RM. O VO2 foi coletado durante o repouso e 10 minutos de recuperação com um analisador de gases (CPX/D). As sessões foram compostas por um exercício de membros superiores (supino) e um de membros inferiores (agachamento), e compreenderam a execução de três séries de 6-8 repetições máximas (RM) a 80% de 1RM para HP e 15-20 RM a 55% de 1RM para RML. Foram analisados os dados de VO2 pós-exercício (EPOC), gasto energético (GE) de recuperação e constante de tempo de VO2 (CT). Foi observado que ambas sessões provocaram comportamento significativamente elevado de VO2 durante os 10min de recuperação em relação aos valores de repouso. Não houve diferenças significativas entre os valores de EPOC (litros) para HP (2,21 ± 0,54) e RML (2,60 ± 0,44), GE (kcal) para HP (10,36 ± 2,53) e RML (12,18 ± 2,04) e CT (segundos) para HP (56 ± 7) e RML (57 ± 6) (p > 0,05). Esses resultados demonstraram que uma sessão de TF com objetivo em RML é capaz de causar distúrbios metabólicos semelhantes àqueles provocados por uma sessão de HP, mesmo que seja em menor intensidade relativa a carga máxima.

The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training

BACKGROUND

The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM) composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training.

METHODS

Male Wistar rats were randomly divided into 8 groups: Sedentary (S) or Exercised (E) [placebo (Pl), creatine (Cr), caffeine (Caf) or creatine plus caffeine (CrCaf)]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW) for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days) or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals), 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's t test.

RESULTS

Exercised animals presented a lower carcass weight (10.9%; P = 0.01), as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05). There were no significant differences among the groups (P > 0.05) for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P < 0.05). A higher percentage of protein was observed in the groups EPl and ECaf when compared to the groups SPl and SCaf (P < 0.001). The percentage of fat in the carcass decreased (P < 0.001), while those of water and protein increased (P < 0.05) in exercised animals, compared to sedentary animals. Caffeine groups presented reduced percentage of fat when compared to creatine supplemented groups (P < 0.05).

CONCLUSIONS

High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine supplementation alone reduces the percentage of fat. Vertical jumping training increases the percentages of water and protein and reduces the fat percentage in rats.

Effect of preceding resistance exercise on metabolism during subsequent aerobic session

The present study was undertaken to evaluate the acute effect of prior resistance training of varying intensities on energy expenditure and substrate utilization during subsequent aerobic exercise. Eleven males and 21 females completed three experimental trials consisting of (1) aerobic exercise only (C), (2) aerobic exercise preceded by a high-intensity resistance training (HI), and (3) aerobic exercise preceded by a low-intensity resistance training (LO). Resistance training produced an equal volume between HI and LO and consisted of six exercises with each performed for three sets of eight repetitions at 90% of 8-RM in HI and three sets of 12 repetitions at 60% of 8-RM in LO. Aerobic exercise was performed on a cycle ergometer at 50% VO(2)peak for 20 min in all trials. Oxygen uptake (VO2), and carbohydrate and fat oxidation were determined throughout each aerobic exercise session. Fat oxidation rate was higher (P < 0.05) in HI than either LO or C in both males and females. VO2 was also higher (P < 0.05) in HI than either LO or C in females. In males, although between-trial differences in VO2 did not reach statistical significance, they were consistent with the trend seen in females. No differences in carbohydrate oxidation rates were observed across the three trials in either gender group. It appears that in training that combines both aerobic and resistance exercises, performing a comparatively higher intensity resistance exercise first would augment fat utilization and energy expenditure during subsequent aerobic exercise.

Effect of intensity of resistance exercise on postprandial lipemia

The purpose of this study is to determine whether moderate-intensity resistance exercise (MOD) lowers postprandial lipemia (PPL) as much as high-intensity resistance exercise (HI) of equal work. Ten healthy men performed three trials, each conducted over 2 days. On day 1 of each treatment, they either did not exercise (CON), performed 3 sets of 16 repetitions of 10 exercises at 50% of 8 repetitions maximum (MOD), or performed 3 sets of 8 repetitions of 10 exercises at 100% of 8 repetitions maximum (HI). On the morning of day 2 at 15.5 h postexercise, participants ate a high-fat meal. Venous blood samples were collected, and metabolic rate was measured at rest and 3 h postprandial. HI reduced fasting triglyceride (TG) and TG area under the curve (AUC) (36%, P = 0.011 and 35%, P = 0.014) compared with CON. MOD tended to reduce fasting TG and TG AUC (21%, P = 0.054 and 26%, P = 0.052) compared with CON, but MOD and HI did not differ in fasting TG or TG AUC. Incremental TG AUC did not differ among treatments. MOD and HI did not change resting metabolic rate. HI increased fat oxidation at rest (21%, P = 0.021) and at 3 h postprandial (39%, P = 0.009) relative to CON. MOD tended to increase fat oxidation at rest (18%, P = 0.060) relative to CON. Fat oxidation and metabolic rate did not differ in MOD and HI. MOD and HI increased the fasting quantitative insulin-sensitivity check index (4%, P = 0.001 and P = 0.004) relative to CON. As MOD and HI resulted in similar reductions in PPL and increases in fat oxidation, resistance exercise intensity does not influence PPL.

Influência das variáveis do treinamento contra-resistência sobre o consumo de oxigênio em excesso após o exercício: uma revisão sistemática

O exercício contra-resistência (ECR) pode contribuir para o aumento da taxa metabólica de repouso (TMR). É consenso na literatura que o volume da sessão de ECR pode repercutir em maior gasto calórico e que, após o exercício, o consumo de oxigênio em excesso (EPOC) pode variar de acordo com a característica do programa de exercício. Contudo, ainda não é possível definir qual ou quais variáveis de prescrição têm maior impacto sobre o EPOC em sessões de ECR. O objetivo do estudo foi efetuar uma revisão sistemática sobre os estudos que se propuseram a investigar as relações entre o EPOC e variáveis de treinamento em ECR. Os 17 estudos selecionados foram agrupados por similaridade de tratamento (número de séries, intensidade, intervalos de recuperação, velocidade da contração muscular e ordem dos exercícios). Técnicas de estatística descritiva foram utilizadas na tentativa de estabelecer possíveis tendências nas relações dose-resposta. Posteriormente, os dados foram analisados de forma qualitativa. De todas as variáveis analisadas, o curto intervalo de recuperação e o modo de prescrição no formato em circuito foram aquelas com maior impacto provável sobre a magnitude do EPOC. Quanto às demais variáveis, limitações metodológicas não permitem estabelecer tendências, principalmente no tocante à duração do EPOC. Adicionalmente, constata-se a necessidade de padronização de aspectos importantes para a quantificação do EPOC, como o tempo de observação do após o exercício e a forma de aferição da TMR.

Os efeitos do treinamento de força sobre os fatores de risco da síndrome metabólica

INTRODUÇÃO: Medidas não-farmacológicas, como a atividade física, vêm sendo recomendadas para prevenção e tratamento de doenças crônicas não transmissíveis. OBJETIVO: Realizar revisão da literatura para verificar os mecanismos por meio dos quais o treinamento de força provoca alterações metabólicas e celulares, agindo positivamente sobre os fatores de risco da síndrome metabólica. METODODOLOGIA: Foram utilizadas as bases de dados Medline, Scielo, Science Direct e Capes. A busca foi restrita aos últimos 10 anos. Os termos utilizados para pesquisa foram: obesity, dislipidemy,hypertension, diabetes mellitus, metabolic syndrome, resistance training, weight lifting, exercise. RESULTADOS: O treinamento de força atua sobre parâmetros metabólicos e celulares promovendo efeitos positivos no controle e na prevenção dos fatores de risco relacionados à síndrome metabólica, tais como diminuição do peso corporal, aumento da sensibilidade à insulina, aumento da tolerância à glicose, diminuição dos níveis pressóricos de repouso e melhoria do perfil lipídico. CONCLUSÃO: A revisão dos artigos científicos apresentados fornece dados que permitem concluir que o treinamento de força pode contribuir de forma efetiva na diminuição dos fatores de risco relacionados à síndrome metabólica.

Efeitos da suplementação de creatina e do treinamento de potência sobre a performance e a massa corporal magra de ratos

INTRODUÇÃO: A creatina é um dos suplementos mais usados por atletas para incrementar a síntese protéica e aumentar a massa e força muscular. OBJETIVO: Investigou-se os efeitos da suplementação de creatina associada a um programa de treinamento de potência (saltos verticais) sobre a performance e a composição da massa corporal magra de ratos Wistar. MÉTODOS: Ratos Wistar adultos foram distribuídos em quatro grupos: SSC (sedentário sem creatina); SC (sedentário com creatina); ESC (exercício sem creatina) e EC (exercício com creatina). Os animais receberam água e ração ad libitum. Os grupos SC e EC ingeriam dose de creatina diariamente, adotando o procedimento de carga (0,430g/kg p.c. por 7 dias) e manutenção (0,070g/kg p.c. por 6 semanas). Os grupos EC e ESC foram submetidos a um regime progressivo de saltos verticais (5x10 saltos com 1 min de intervalo) em tanque com água, 5 dias/semana, durante 7 semanas. A performance foi avaliada pelo tempo de execução das 5 séries de 10 saltos verticais e a composição da massa corporal magra (músculos e ossos) foi avaliada pelas porções: água, proteína e gordura. RESULTADOS: A performance não foi afetada pela ingestão de creatina (p > 0,05). Os animais suplementados tiveram o percentual de proteína elevado e o de gordura reduzido (p < 0,05), independente do treinamento. Os animais exercitados exibiram maior percentual de proteína, e menor de gordura, além de menor ganho de peso corporal, comparados com os sedentários, independente da suplementação (p < 0,05). Não houve diferença para o percentual de água e consumo alimentar (p > 0,05). CONCLUSÃO: A suplementação de creatina não afetou a performance dos animais, mas alterou a massa corporal magra. A suplementação de creatina e o programa de treinamento de potência, de forma independente, elevaram o percentual de proteína dos músculos e ossos e reduziram o percentual de gordura, sem alterar o percentual de água.

Effect of Explosive versus Slow Contractions and Exercise Intensity on Energy Expenditure

OBJECTIVE

The primary purpose of this study was to compare the effects of explosive versus slow contractions on the rate of energy expenditure during and after resistance exercise.

METHODS

Nine men (20 +/- 2.5 yr) performed three exercise protocols using a plate-loaded squat machine, and a no-exercise (CONTROL) session in a randomly assigned, counterbalanced order. Subjects performed squats using either two second (SLOW) or explosive concentric contractions (EXPL), but identical repetitions (8), sets (4), and loads (60% 1RM). A secondary objective was to compare high- versus moderate-intensity exercise. Thus, a third protocol was performed that also used explosive contractions, with heavier loads (80% 1RM) and six sets of four reps (HEAVYEXPL). Eccentric reps (2 s), work (reps x sets x load), range of motion, and rest intervals between sets (90 s) were identical among all three protocols. Expired air was collected continuously for 20 min before, during, and 1 h after exercise and for about 1.5 h during CONTROL. Blood samples (25 microL) were collected before, immediately after, and 15, 30, 45, and 60 min after each protocol, and these samples were analyzed for blood lactate (mM).

RESULTS

Average rates of energy expenditure (kcal.min) were significantly greater (P <or= 0.05) during (7.27 +/- 2.00 > 6.43 +/- 1.64 and 6.25 +/- 1.55, respectively) and after (2.54 +/- 1.44 > 2.38 +/- 1.31 and 2.21 +/- 1.08, respectively) EXPL compared with SLOW and HEAVYEXPL, despite significantly (P <or= 0.05) greater blood lactate after SLOW.

CONCLUSION

Squat exercise using explosive contractions and moderate intensity induced a greater increase in the rate of energy expenditure than squats using slow contractions or high intensity in all subjects tested. Thus, by using explosive contractions and moderate exercise intensity, experienced recreational exercisers can increase their energy expenditure during and after resistance exercise, and this could enhance weight-loss adaptations.

Gasto energético e consumo de oxigênio pós-exercício contra-resistência

O aumento do gasto energético com a atividade física é reconhecido como um importante coadjuvante em programas para redução da massa corporal. Porém, o impacto do exercício contra-resistência, incluindo o consumo de oxigênio em excesso pós-exercício sobre o gasto energético ainda é questionável. O objetivo desta revisão foi discutir a influência das variáveis do exercício contra-resistência (isto é, intensidade, intervalo de recuperação, velocidade de execução, número de séries, e modo - circuito ou contínuo) sobre o gasto energético durante e após uma sessão de exercícios, envolvendo uma discussão sobre os possíveis mecanismos do consumo de oxigênio em excesso pós-exercício. As inúmeras possibilidades de combinação entre tais variáveis podem favorecer uma variabilidade bastante grande no gasto energético de uma sessão de exercício contra-resistência (aproximadamente de 3 a 10kcal.min-1). Contudo, o volume total de trabalho parece ser determinante no gasto energético da sessão. O consumo de oxigênio em excesso pós-exercício, por outro lado, parece ser afetado pela intensidade. A manipulação das variáveis do exercício contra-resistência pode afetar os processos metabólicos subjacentes ao consumo de oxigênio em excesso pós-exercício, o que inclui ressíntese dos estoques de fosfato de alta energia, ressaturação da oximioglobina e oxihemoglobina, efeitos termogênicos, remoção de lactato, aumento no turnover protéico, e processos desencadeados pela estimulação simpática. Conclui-se que, para indivíduos destreinados e com sobrepeso, a prescrição de escolha poderia ser a de sessões de baixa intensidade e alto volume. Contudo, para indivíduos treinados, o aumento do gasto energético, a partir da execução de sessões de exercício contra-resistência mais intensas, pode ser adequado, dada a influência da intensidade sobre o consumo de oxigênio em excesso pós-exercício. Dessa forma, para a prescrição dietética, o nutricionista deve considerar e se beneficiar dos efeitos do treinamento com exercício contra-resistência sobre o aumento do gasto energético.

Efeito do consumo excessivo de oxigênio após exercício e da taxa metabólica de repouso no gasto energético

A crescente prevalência de obesidade e sobrepeso ressalta a necessidade de intervenções para reverter esse quadro. Nesse contexto, a atividade física pode contribuir com um efeito duplo, por meio de mudanças fisiológicas agudas e crônicas: na primeira condição encontra-se o gasto energético do exercício e recuperação (EPOC - consumo excessivo de oxigênio após o exercício), e na segunda encontra-se a taxa metabólica de repouso (TMR). Dessa forma, o objetivo deste trabalho de revisão foi investigar o efeito do EPOC e da TMR como coadjuvantes nos programas de emagrecimento, buscando discutir os divergentes resultados encontrados na literatura, no que diz respeito à magnitude e duração do EPOC, bem como discutir o efeito do exercício na TMR. Os estudos demonstram, de forma geral, que o exercício de maior intensidade é capaz de promover maior EPOC, se comparado com um exercício de intensidade menor e, quando comparam o exercício resistido com o aeróbio, verifica-se maior EPOC no primeiro. Em relação às alterações da TMR, os resultados agudos mostram aumento significativo, porém os resultados em longo prazo são mais discrepantes, devido à dificuldade de mensurar essa variável, sem superestimá-la. Concluindo, a literatura aponta que a periodização de um treinamento que possa maximizar tanto o EPOC quanto a TMR podem ser importantes fatores para o emagrecimento e, embora, o custo energético dessas variáveis em uma sessão de exercício se mostre pequeno, em longo prazo poderá ser bastante significativo. No entanto, novos estudos deverão ser realizados com o intuito de confirmar essas evidências.

Excess post-exercise oxygen consumption in untrained males: effects of intermittent durations of arm ergometry

The purpose of this study was to investigate excess post-exercise oxygen consumption (EPOC) following a continuous 30 min bout of upper-body exercise (UBE) compared with 3 consecutive 10 min bouts of UBE. Ten male subjects (age (mean +/- standard deviation), 25.7 +/- 5.83 years; arm VO(2) (peak), 2.2 +/- 0.25 L x min(-1), on separate days (48 h between trials) and in counterbalanced order, performed a continuous 30 min bout of arm exercise at 60% of arm VO2 peak and 3 separate 10 min bouts of arm exercise at 60% of arm VO(2) (peak). Subjects reported to the laboratory rested and after a 12 h fast. Each test was preceded by a 30 min baseline test to determine resting metabolic rate. Post-exercise VO2 was continuously monitored until baseline was re-established. Results showed that the combined magnitude of the EPOCs from the intermittent exercise sessions was significantly (p > .05) greater (4.47 +/- 1.58 L O2) than that elicited from the continuous exercise session (1.54 +/- 1.25 L O2). These data indicate that separating a continuous 30 min arm exercise into 3 equal 10 min arm exercises will elicit a small but significantly higher EPOC, and thus result in greater post-exercise energy expenditure. This could be beneficial for those unable to perform lower-body exercise (LBE), or for those with limited exercise capacities.

Acute EPOC response in women to circuit training and treadmill exercise of matched oxygen consumption

The purpose of the study was to evaluate the effects of circuit training (CT) and treadmill exercise performed at matched rates of oxygen consumption and exercise duration on elevated post-exercise oxygen consumption (EPOC) in untrained women, while controlling for the menstrual cycle. Eight, untrained females (31.3 +/- 9.1 years; 2.04 +/- 0.26 l min(-1) estimated VO2max; BMI=24.6+/-3.9 kg/m2) volunteered to participate in the study. Testing was performed during the early follicular phase for each subject to minimize hormonal variability between tests. Subjects performed two exercise sessions approximately 28 days apart. Resting, supine energy expenditure was measured for 30 min preceding exercise and for 1 h after completion of exercise. Respiratory gas exchange data were collected continuously during rest and exercise periods via indirect calorimetry. CT consisted of three sets of eight common resistance exercises. Pre-exercise and exercise oxygen consumption was not different between testing days (P>0.05). Thus, exercise conditions were appropriately matched. Analysis of EPOC data revealed that CT resulted in a significantly higher (p<0.05) oxygen uptake during the first 30 min of recovery (0.27 +/- 0.01 l min(-1) vs 0.23+/-0.01 l min(-1)); though, at 60 min, treatment differences were not present. Mean VO2 remained significantly higher (0.231 +/- 0.01 l min(-1)) than pre-exercise measures (0.193 +/- 0.01 l min(-1)) throughout the 60-min EPOC period (p<0.05). Heart rate, RPE, V(E) and RER were all significantly greater during CT (p<0.05). When exercise VO2 and exercise duration were matched, CT was associated with a greater metabolic disturbance and cost during the early phases of EPOC.

Análise do consumo de oxigênio, freqüência cardíaca e dispêndio energético, durante as aulas do Jump Fit

As aulas de Jump Fit promovem a melhora da aptidão física geral, através de coreografias executadas sobre uma superfície elástica com variação de ritmo e movimentos, de forma intervalada, com baixo impacto. Contudo, pouco se sabe sobre o real dispêndio energético e o comportamento das variáveis metabólicas relacionadas às aulas do Jump Fit. O objetivo deste estudo foi identificar e avaliar o comportamento das variáveis funcionais, tais como: freqüência cardíaca (FC), consumo de oxigênio (VO2), produção de dióxido de carbono (VCO2), quociente respiratório (QR), equivalente metabólico (MET) e dispêndio energético, através da mensuração por espirometria da rotina de uma aula de Jump Fit. Os testes foram realizados em quatro visitas, por 10 mulheres praticantes do Jump Fit, com idade de 26,8 anos (± 7,2), massa corporal de 57,6kg (± 6,8), estatura de 162,2cm (± 3,9). A avaliação espirométrica das diversas etapas da aula revelou os seguintes resultados médios: FC de 160,3bpm (± 8,9), VO2 de 1,59L.min-1 (± 0,45), QR 0,87 (± 0,10) e dispêndio energético total 386,4kcal (± 13,8). A intensidade média da aula de Jump Fit correspondeu a 75% (± 7,7) do VO2pico. Para a análise do comportamento das variáveis metabólicas nas diferentes etapas das aulas recorreu-se à ANOVA para medidas repetidas, com verificação de Bonferroni. O teste t foi utilizado para identificar se houve diferença entre as respostas funcionais nas fases de repouso e do EPOC. Foi adotado nível de significância de p < 0,05. Conclui-se que, a partir da magnitude das respostas funcionais, a aula do Jump Fit proporciona aumento da resistência cardiorrespiratória, contribuindo de forma efetiva para a manutenção e melhora da aptidão física e saúde na qualidade de vida.

Efeitos agudos da atividade contra-resistência sobre o gasto energético: revisitando o impacto das principais variáveis

Considerando a crescente prevalência de sobrepeso e obesidade no Brasil e em várias partes do mundo, tornam-se necessárias estratégias que busquem o seu controle. A associação entre dieta e exercícios físicos aeróbios é, há muito, reconhecida como uma maneira inócua e efetiva de contornar o problema; já o impacto da atividade contra-resistência na perda de peso é, ainda, bastante questionável. Assim, o objetivo da presente revisão foi discutir o efeito termogênico da atividade contra-resistência, buscando esclarecer o impacto das diversas variáveis - intensidade, duração, número de séries, intervalo entre séries, velocidade de execução e modo (circuito ou séries múltiplas) a ela relacionadas. Os estudos apontam que a atividade contra-resistência pode aumentar o gasto energético total de forma aguda, através do próprio custo energético de sua execução, assim como durante o período de recuperação (EPOC). É reconhecido, também, que as diversas variáveis associadas ao exercício contra-resistência afetam de maneiras distintas os resultados obtidos. Número de repetições, carga, intervalo de recuperação entre séries e número de séries, quando manipulados de forma a aumentar o volume ou a intensidade da atividade, podem, em última análise, aumentar sobremaneira o gasto energético decorrente de uma sessão típica de exercícios. De maneira geral, considerando todas as limitações dos estudos revisados, a literatura aponta que o volume é a variável de maior impacto sobre o gasto energético durante a realização da atividade e a intensidade sobre o EPOC.

Resistance and aerobic exercise have similar effects on 24-h nutrient oxidation

BACKGROUND

Whether resistance exercise is as effective as aerobic exercise for body-weight management is debated.

PURPOSE

To compare 24-h energy expenditure (EE) and macronutrient oxidation elicited by comparable bouts of stationary cycling (BK) and weightlifting (WTS).

METHODS

24-h EE and macronutrient oxidation were measured in 10 nonobese male subjects on three occasions using whole-room indirect calorimetry. BK and WTS days were compared with a nonexercise control day (Con).

RESULTS

During BK, subjects exercised for 49 +/- 7 min (mean +/- SEM) at 70% of OV(2max) and expended 546 +/- 16 kcal. During WTS, subjects performed a 70-min circuit consisting of four sets of 10 different exercises at 70% of exercise-specific 1-repetition maximum and expended 448 +/- 21 kcal (P < 0.001 vs BK). 24-h EE on BK and WTS days (2,787 +/- 76 kcal x d(-1), 2,730 +/- 106 kcal x d(-1), respectively, P > 0.05) was elevated compared with Con (2,260 +/- 96 kcal x d(-1), P < 0.001), but 24-h respiratory exchange ratio (RER) was not different. 24-h carbohydrate oxidation was significantly elevated on the exercise days (BK = 370 +/- 18 g x d(-1), WTS = 349 +/- 23 g x d(-1), P > 0.05) compared with Con (249 +/- 29 g x d(-1), P = 0.04). 24-h fat and protein oxidation were the same on BK, WTS, and Con days. EE and macronutrient oxidation in the periods after exercise also did not differ across conditions.

CONCLUSION

In men, resistance exercise has a similar effect on 24-h EE and macronutrient oxidation as a comparable bout of aerobic exercise. Neither exercise produced an increase in 24-h fat oxidation above that observed on a nonexercise control day.