Comparison of 8-weeks of full versus split body resistance training on appetite and energy intake in non-obese untrained men.

To investigate the effects of 8-weeks of full versus split body resistance training (RT) on appetite and energy intake in non-obese untrained men. The participants were pair-matched based on their initial fat mass and then randomly allocated into one of two treatment groups: Full body (FB, n = 20), in which all muscle groups were trained in every session, or Split body (SB, n = 15), in which upper and lower muscle groups were trained alternated per session; both groups trained in non-consecutive days, three times per week with total number of sets performed equated between groups. Energy intake, body composition, and strength performance were evaluated at pre-training, and after 8-weeks of RT, as well as self-reported hunger, fullness, and desire to eat, that were assessed at fasted and feed states pre- and post-intervention. FB and SB resistance training increased fat-free mass (FFM) (p < 0.001); and FB induced greater maximal strength improvement (p = 0.027). At fasted state self-reported hunger increased, and fullness decreased, while in feed state desire to eat something fatty increased in both groups. Carbohydrate intake (p = 0.011) decreased in both groups. In conclusion, FB and SB training increased orexigenic drive (increasing hunger and decreasing fullness), however, total energy intake and fat mass did not change after 8-weeks of RT in non-obese untrained men.Registered under Brazilian Registry of Clinical Trials no. RBR-3wkcvyw.

The impact of acute and chronic resistance training on appetite and energy intake: A scoping review examining resistance exercise and comparisons with other exercise modalities.

PURPOSE: The effects of exercise on appetite have recently been systematically evaluated with a focus on endurance training (ET). However, resistance training (RT) may induce different adaptations than ET. This scoping review aimed to examine the acute and chronic effects of isolated RT and comparisons with other exercise modalities on appetite-related variables and energy intake. RESULTS: 17 acute studies were identified, six examining isolated RT, while 11 focused on RT intensity, amount of exercise, targeted muscle groups, or comparison with ET and combined training (RT plus ET; CT). Nine chronic studies were identified. Three investigated isolated RT vs control and six manipulated the amount of RT exercise, types of RT, or comparison with ET and CT. CONCLUSIONS: Acute RT compared to control conditions appears to induce responses favoring appetite inhibition. While the amount of RT exercise may acutely play a role in the suppression of appetite, while ET seems to have more potential to suppress appetite. Chronic RT does not seem to stimulate compensatory mechanisms; however, there is not clear evidence regarding the role of RT intensity or other exercise modalities. Chronic ET and CT may be more prone to favor appetite inhibition than RT. More comprehensive evaluations including the exploration of multiple appetite-related factors are needed for future studies.

Ten weeks of Capsicum annuum L. extract supplementation did not change adipose tissue-derived hormones, appetite, body composition, and muscle strength when combined with resistance training in healthy untrained men: A clinical trial study.

Capsiate (CAP) is a nonpungent capsaicin analog (Capsicum annuum L. extract) that has been studied as a potential antiobesity agent. However, the interaction between chronic CAP supplementation and resistance training is not clear. The purpose of this study was to examine the changes in adipose tissue-derived hormones, body composition, appetite, and muscle strength after 10 weeks of resistance training, combined with chronic CAP supplementation in healthy untrained men. We hypothesized that CAP could induce higher benefits when combined with resistance training after 10 weeks of intervention compared to resistance training alone. Twenty-four young men (age, 22.0 ± 2.9) were randomized to either capsiate supplementation (CAP = 12 mg/day) or placebo (PL), and both groups were assigned to resistance training. Body composition, leptin and adiponectin concentrations, subjective ratings of appetite, energy intake, and exercise performance were assessed at before and after 10 weeks of progressive resistance training. There was a significant increase in body mass (P < .001), fat-free mass (CAP: 58.0 ± 7.1 vs. post, 59.7 ± 7.1 kg; PL: pre, 58.4 ± 7.3 vs. post, 59.8 ± 7.1 kg; P < .001), resting metabolic rate (CAP: pre, 1782.9 ± 160.6 vs. post, 1796.3 ± 162.0 kcal; PL: pre, 1733.0 ± 148.9 vs. post, 1750.5 ± 149.8 kcal; P < .001), maximal strength at 45 leg press (P < .001) and bench press (P < .001) in both groups, but no significant (P > .05) supplementation by training period interaction nor fat mass was observed. For subjective ratings of appetite, energy intake, leptin, and adiponectin, no significant effect of supplementation by training period interaction was observed (P > .05). In conclusion, 10 weeks of resistance training increased total body weight, muscle mass, and maximum strength in healthy untrained men; however, CAP supplementation (12 mg, 7 days per week) failed to change adipose tissue-derived hormones, appetite, body composition and muscle strength in this population. Registered under Brazilian Registry of Clinical Trials (RBR-8cz9kfq).

Physical demands in a small-sided soccer game: a comparison between arbitrary and individualized speed and metabolic power thresholds.

BACKGROUND: This study compared the arbitrary and individualized speed and metabolic power (Pmet) intensity thresholds in a small-sided game (SSG) regarding: 1) distance covered; 2) variations of the physical parameters during the SSG; and 3) associations with physical fitness. METHODS: Twenty-four amateur soccer players (age: 20.0±1.7 years; height: 176.4±4.2 cm; body mass: 67.6±3.2 kg), after being tested for maximal aerobic speed (MAS) and maximal sprinting speed (MSS), participated in a SSG in a separate session and were monitored with global positioning systems (GPS). The distance covered was classified into three intensity zones for each variable (speed and Pmet) using arbitrary and individualized zones based on MAS. RESULTS: There were differences in the distance covered between methods in zones 1 and 2 for both speed and Pmet (P<0.001), and in zone 3 only for Pmet (P<0.001). There were no variations in any variable analyzed during the SSG. MAS was positively correlated with the distance covered in zone 3 in the arbitrary speed (r=0.67; P<0.001) and Pmet (r=0.60; P<0.01). MSS was negatively correlated with the distance covered in zone 3 in the individualized speed (r=-0.49; P<0.05) and Pmet (r=-0.48; P<0.05). CONCLUSIONS: This study showed that arbitrary and individualized provide different information. While the individualized method could be used to monitor physical demands, the arbitrary could be used to assess running physical performance.

Home-based training program during the SARS-CoV-2 quarantine: training load, motivation, and wellbeing in professional elite female basketball players.

BACKGROUND: Due to the quarantine caused by the Coronavirus disease 2019 (COVID-19), professional team-sports adapted their training routine to maintain the athletes' performance and minimize the negative emotional effects. The aim of the present study was to describe a home-based training program and extra-activities applied during the quarantine in elite professional female basketball players, and to compare the internal training load (ITL), session rating of perceived exertion (s-RPE), motivation, and wellbeing responses before and during the quarantine. METHODS: Nine female elite players (25.7±7.0 years; 180.0±8.0 cm; 79.0±11.0 kg) belonging to a professional basketball team performed a home-based training program during the quarantine. ITL, s-RPE, training motivation, and wellbeing were examined before (phase 1), at the beginning (phase 2), and during (phase 3) the quarantine. RESULTS: ITL was higher (main effect) in phase 1 (449.5±62.8 a.u.) compared to phase 2 (265.5±39.0 a.u.) and phase 3 (423.1±18.7 a.u.); s-RPE was higher in phase 1 (4.50±0.63 a.u.) compared to phase 2 (3.8±0.6 a.u.), but not to phase 3 (4.37±0.79 a.u.). Motivation was higher in phase 1 (3.6±0.3 a.u.) compared to phase 2 (2.3±0.6 a.u.) and phase 3 (2.4±0.5 a.u.). CONCLUSIONS: The results of the study demonstrated that extra-activities involving online athletes' socialization were implemented to rouse the motivation, but the quarantine period induced a reduction in ITL and influenced the player's training motivation.

Acute Response to Capsiate Supplementation at Rest and during Exercise on Energy Intake, Appetite, Metabolism, and Autonomic Function: A Randomized Trial.

OBJECTIVE: The purpose of the present study was to examine the effect of capsiate supplementation on energy intake, self-reported appetite-related sensations, energy expenditure, fat oxidation, and autonomic parameters with and without an exercise intervention. METHODS: Thirteen healthy men completed four randomized trials: two trials for the control condition (without exercise), one with capsiate supplementation (CTRLcap) and one with a placebo (CTRLpla), and two trials for the exercise condition, one with capsiate supplementation (EXcap) and one with placebo (EXpla). Exercise sessions were performed 150 min after the consumption of a standardized breakfast, and supplementation 115 min after consumption of breakfast. An ad libitum buffet was offered 200 min following the completion of the standardized breakfast, and energy intake (EI) and relative energy intake (REI) (relative energy intake = energy intake - energy expenditure related to exercise) were evaluated. RESULTS: There were no significant effects on EI, self-reported appetite sensations, fat oxidation, and energy expenditure. REI was reduced in conditions involving EX when compared to CTRL. A low-frequency to high-frequency ratio for heart rate variability was higher in CTRLcap (1.6 ± 1.1) vs. CTRLpla (1.2 ± 0.9) (p = 0.025; d = 0.39). CONCLUSION: Acute capsiate supplementation combined with aerobic exercise has limited effects on the examined variables (EI, REI, fat oxidation, energy expenditure, and autonomic parameters), while changes in the autonomic nervous system function in the absence of exercise may have occurred without influencing other variables. CLINICAL TRIAL REGISTRATION: ensaiosclinicos.gov.br number, RBR-5pckyr https://ensaiosclinicos.gov.br/rg/RBR-5pckyr.

Magnitude and duration of excess of post-exercise oxygen consumption between high-intensity interval and moderate-intensity continuous exercise: A systematic review.

The present systematic review examined the effect of exercise intensity (high-intensity interval exercise [HIIE] vs. moderate-intensity continuous exercise [MICE] vs. sprint interval exercise [SIE]) on excess post-exercise oxygen consumption (EPOC). Twenty-two studies were included in the final evaluation. The retrieved investigations were split into studies that analysed short-duration (until 3 h) and long-duration (more than 3 h) EPOC. Studies that subtracted the baseline energy expenditure (EE) were analysed separately from those that did not. Most short-duration evaluations that subtracted baseline EE reported higher EPOC for HIIE (average of ~136 kJ) compared with MICE (average of ~101 kJ) and higher values for SIE (average of ~241 kJ) compared with MICE (average of ~151 kJ). The long-duration evaluations resulted in greater EPOC for HIIE (average of ~289 kJ) compared with MICE (average of ~159 kJ), while no studies comparing SIE versus MICE provided appropriate values. EE from EPOC seems to be greater following HIIE and SIE compared with MICE, and long-duration evaluations seem to present higher values than short-duration evaluations. Additionally, more standardized methodologies are needed in order to determine the effective EPOC time following these protocols.

Assessment of aerobic fitness in individuals with and without nonspecific chronic low back pain: a pilot study.

Aerobic fitness assessment in patients with low back pain (LBP) may help clinicians to plan how to progress the aerobic training. This was a pilot study designed to evaluate the performance of people with LBP on two different aerobic fitness tests performed on a treadmill and to compare the measure of aerobic fitness between people with LBP and healthy individuals. Ten people with LBP and 10 healthy individuals underwent two aerobic fitness protocols, the modified Bruce and maximum incremental test protocols, performed on a treadmill. Data collected during the protocols were: oxygen consumption, heart rate (HR), blood lactate concentration, respiratory quotient, rating of perceived exertion response, and pain intensity. Independent t-test and two-way analysis of variance were used respectively to assess difference between groups characteristics and physiological responses to the protocols. Our results showed that both groups were similar with regards to age (P = 0.839) or HRrest (P = 0.730) but the LBP group showed higher BMI compared to the healthy group (P = 0.031). Regarding the performance of both groups on the aerobic fitness tests, the only significant difference was reported for respiratory quotient which showed a main effect of test (P = 0.015) with higher values favoring the modified Bruce over the incremental test. Our study showed that most people with LBP are able to perform and tolerate both aerobic fitness tests but no significant differences between people with LBP and healthy individuals on both protocols were reported.

Acute Capsaicin Analog Supplementation Improves 400 M and 3000 M Running Time-Trial Performance.

OBJECTIVES: Performance in running-based sport depends on the ability to perform repetitive high intensity muscle contractions. Previous studies have shown that capsaicin analog (CAP) (i.e. Capsiate) supplementation may improve this performance. The purpose of this study was to investigate the acute effect of CAP supplementation on short (400 m) and middle distance (3000 m) running time-trial performance, maximum heart rate (HR), and rate of perceived exertion (RPE). METHODS: Twelve physically active men completed four randomized, double-blind trials: CAP condition (12 mg) or a placebo condition. Forty-five minutes after supplementation, the participants performed a 400- or 3000-meter running time trial. Time (in seconds) was recorded. HR was analyzed at rest and immediately post-exercise, and RPE was collected immediately after exercise. RESULTS: For both the 400 m time-trial (CAP = 66.4 + 4.2 sec vs Placebo = 67.1 + 4.8 sec, p = 0.046) and the 3000 m time-trial (CAP = 893.9 ± 46.8 sec vs Placebo = 915.2 ± 67.6 sec, p = 0.015), the time in seconds was significantly less in the CAP compared to placebo conditions. There were no statistically significant differences for HR and RPE in any condition. CONCLUSION: In summary, acute CAP supplementation improved 400 m and 3000 m running time-trial performance in a distance-dependent way but without modifying the HR and RPE.

Postactivation potentiation attenuates resistance exercise performance decrements following aerobic exercise in trained men.

BACKGROUND: The purpose of this study was to investigate if a post-activation potentiation (PAP) protocol may attenuate the acute interference induced by high-intensity intermittent exercise (HIIE) and on subsequent strength exercise performance in recreationally trained men. METHODS: Eleven resistance-trained men (age: 25.7±3.7 y) randomly completed three experimental trials: strength exercise (SE) only (4 sets of maximal number of repetitions at 70% on the 45º leg press); concurrent exercise (CE) comprised 5000-m of HIIE at maximal aerobic speed (1:1 effort and pause ratio) followed by SE protocol; CE with post-activation potentiation (CE-PAP), comprised the same CE protocol preceded by one set of 2 repetitions at 90% of 1RM on the 45° leg-press before strength exercise. The number of repetitions performed was recorded for each set and total weight lifted was calculated. RESULTS: The CE condition induced a greater decrement in volume for the leg press compared to SE and CE-PAP in sets 1 (24±21%; 18±25%), 2 (20±21%; 22±22%), and 3 (19±20%; 25±15%), respectively. Total weight lifted was greater after SE (8,795±2,581 kg) and CE-PAP (8.809±2.655 kg) conditions compared to CE (7.049±2.822 kg) (SE vs. CE: P=0.020) and (CE-PAP vs. CE: P=0.010) but there was no significant difference between SE and CE-PAP (P=1.00). CONCLUSIONS: PAP using a heavy load attenuated acute interference (total volume during lower-body strength) generated by HIIE protocol, but did not enhance volume compared to SE alone.

The acute effects of thermogenic fitness drink formulas containing 140 mg and 100 mg of caffeine on energy expenditure and fat metabolism at rest and during exercise.

BACKGROUND: Thermogenic fitness drink formulas (TFD) have been shown to increase energy expenditure and markers of lipid metabolism. The purpose of the current study was to compare TFD formulas containing different caffeine concentrations versus a placebo drink on energy expenditure and lipid metabolism at rest and during exercise. METHODS: Thirty-two recreationally active participants (22.9 ± 0.7 y, 167.1 ± 1.4 cm, 68.8 ± 2.0 kg, 24.0 ± 1.2% fat) who were regular caffeine consumers, participated in this randomized, double-blind, crossover design study. Participants reported to the laboratory on three occasions, each of which required consumption of either a TFD containing 140 mg or 100 mg of caffeine or a placebo. Baseline measurements of resting energy expenditure (REE) and resting fat oxidation (RFO) were assessed using indirect calorimetry as well as measurements of serum glycerol concentration. Measurements were repeated at 30, 60, 90 min post-ingestion. Following resting measures, participants completed a graded exercise test to determine maximal oxygen uptake (V̇O2max), maximal fat oxidation (MFO) and the exercise intensity that elicits MFO (Fatmax), and total energy expenditure (EE). RESULTS: A significant interaction was shown for REE (p < 0.01) and RFO (p < 0.01). Area under the curve analysis showed an increased REE for the 140 mg compared to the 100 mg formula (p = 0.02) and placebo (p < 0.01) and an increased REE for the 100 mg formula compared to placebo (p = 0.02). RFO significantly decreased for caffeinated formulas at 30 min post ingestion compared to placebo and baseline (p < 0.01) and significantly increased for the 140 mg formula at 60 min post-ingestion (p = 0.03). A main effect was shown for serum glycerol concentrations over time (p < 0.01). No significant differences were shown for V̇O2max (p = 0.12), Fatmax (p = 0.22), and MFO (p = 0.05), and EE (p = 0.08) across drinks. CONCLUSIONS: Our results suggest that TFD formulas containing 100 and 140 mg of caffeine are effective in increasing REE and that a 40 mg of caffeine difference between the tested formulas may impact REE and RFO in healthy individuals within 60 min of ingestion.

Alterations in energy system contribution following upper body sprint interval training.

PURPOSE: The primary purpose of this study was to examine the influence of different work-to-rest ratios on relative energy system utilization during short-term upper-body sprint interval training (SIT) protocols. METHODS: Forty-two recreationally trained men were randomized into one of three training groups [10 s work bouts with 2 min of rest (10:2, n = 11) or 4 min of rest (10:4, n = 11), or 30 s work bouts with 4 min of rest (30:4, n = 10)] or a control group (CON, n = 10). Participants underwent six training sessions over 2 weeks with 4-6 'all-out' sprints. Participants completed an upper body Wingate test (30 s 'all-out' using 0.05 kg kg-1 of the participant's body mass) pre- and post-intervention from which oxygen consumption and blood lactate were used to estimate oxidative, glycolytic, and adenosine triphosphate-phosphocreatine (ATP-PCr) energy system provisions. An analysis of covariance was performed on all testing measurements collected at post with the associated pre-values used as covariates. RESULTS: Relative energy contribution (p = 0.026) and energy expenditure (p = 0.019) of the ATP-PCr energy system were greater in 10:4 (49.9%; 62.1 kJ) compared to CON (43.1%; 47.2 kJ) post training. No significant differences were found between groups in glycolytic or oxidative energy contribution over a 30 s upper body Wingate test. CONCLUSION: SIT protocols with smaller work-to-rest ratios may enhance ATP-PCr utilization in a 30 s upper body Wingate over a 2-week intervention.

Use of the anaerobic speed reserve to normalize the prescription of high-intensity interval exercise intensity.

The aim of this study was to compare the perceptual and physiological responses and time-to-exhaustion in high intensity interval exercise (HIIE) protocols that are prescribed based on the relative anaerobic speed reserve (ASR) or maximal aerobic speed (MAS) in athletes with different ASR values, as well as the coefficient of variation (CV) of the abovementioned variables. Eleven long-distance runners and ten rugby players were submitted to five experimental sessions on different days; the first and second session were intended for the determination of the anthropometry, MAS and maximal sprint (MSS). In the subsequent sessions, three HIIE15:15s protocols were performed until exhaustion (110%MAS, Δ25%ASR, and Δ50%ASR) in random order. The anthropometric characteristics and variables obtained from the MAS and MSS tests in the different groups were compared by Student's unpaired t-test. The analysis of mixed models for repeated measures (groups and protocols) was used to compare the speed, delta blood lactate, rating of perceived exertion, and time-to-exhaustion. Rugby players presented higher ASR (13.6 ± 0.9 km h-1) compared to long-distance runners (12.6 ± 0.9 km h-1) (P = .049). For the HIIE15:15s protocols, there were no protocol and group interaction effects. However, lower CV values were observed for time-to-exhaustion (a mean reduction of 52%) and delta blood lactate (a mean reduction of 48%) in Δ25%ASR and Δ50%ASR when compared to 110%MAS. Furthermore, the rating of perceived exertion CV was similar in all HIIE15:15s protocols. The prescription of intensity of HIIE based on the ASR was able to reduce the inter-subject variability of lactate and time-to-exhaustion in rugby players and long-distance runners.

Influence of Acute and Chronic High-Intensity Intermittent Aerobic Plus Strength Exercise on BDNF, Lipid and Autonomic Parameters.

The purpose of the present study is two-fold. First, we evaluated whether 8-weeks of combined training (high-intensity intermittent plus strength training) may change brain derived neurotropic factor (BDNF) and lipid parameters (triacylglycerol, HDL-c and non-HDL) in a fasted state. Second, we investigated the effect of an acute session of high-intensity intermittent exercise followed by strength training on systemic BDNF and lipid parameters pre- and post 8-weeks of training. Twenty-one healthy and physically active men were divided into two groups: high-intensity intermittent exercise combined with strength training (HSG; n = 11) and control (CG; n = 10). The HSG exercised for one minute at 100% of speedVO2max (sVO2max) interspersed with one minute of passive recovery followed by strength training (8 exercises with 8-12 repetition maximum loads) for 8-weeks. Heart rate variability, blood pressure, lipid profile, and BDNF concentrations were measured in the fasted state pre- and post-exercise and before and after the 8-week training period. After 8-weeks of exercise training, there was an increase in spectral high frequency component (ms2) and RR interval (p < 0.05), a decreased spectral low frequency component (nu) and heart rate values (p < 0.05), an increase in HDL-c (p < 0.001), and lower BDNF concentrations (p < 0.001). These results suggest that 8-weeks of high-intensity intermittent exercise combined with strength exercise is an effective protective cardio-metabolic strategy capable of increasing HDL-c and BDNF concentrations after an acute exercise session. In the long-term, the modulation on BDNF and HDL-c concentrations may be a determining factor for protection against neurological and cardiovascular diseases.

Energy System Contributions in Upper and Lower Body Wingate Tests in Highly Trained Athletes.

PURPOSE: This study compared the energy system contributions and relationship between mechanical and energy system variables in upper and lower body Wingate tests (WAnT) in judo athletes. METHOD: Eleven male judo athletes (18 ± 1 years, 174.3 ± 5.3 cm, 72.6 ± 9.9 kg, 11.8 ± 1.7% body fat) attended two laboratory sessions to perform two WAnT (upper and lower body) and two incremental tests (upper and lower body). The energy contributions of the oxidative, glycolytic, and phosphagen (ATP-PCr) systems were estimated based on oxygen consumption ( V˙O2 ) during WAnT, delta of lactate, and the fast phase of excess V˙O2 , respectively. RESULTS: The upper and lower body presented similar results of oxidative (21 ± 4% vs 23 ± 3%) and ATP-PCr system contributions (29 ± 6% vs 32 ± 5%). The glycolytic system contribution (50 ± 5% vs 45 ± 4%) was higher in the upper body. The variance of mechanical variables in upper body was explained by glycolytic (R2 = 0.49-0.62) and oxidative systems (R2 = 0.44-0.49), whereas the variance of mechanical variables in lower body was explained by ATP-PCr (R2 = 0.41-0.55) and glycolytic systems (R2 = 0.62-0.94). CONCLUSIONS: During WAnT, the glycolytic system presented the major energy contribution, being higher in the upper body. Moreover, mechanical and energy system variables presented a distinct relationship when comparing upper and lower body WAnT.

Maximum Strength Development and Volume-Load during Concurrent High Intensity Intermittent Training Plus Strength or Strength-Only Training.

The purpose of this study was to compare maximal strength gains during strength training (ST) and concurrent training (CT) consisting of high-intensity intermittent training plus strength training over the course of a 12-week intervention. A secondary purpose was to examine the relationship between strength training volume and strength gain in both groups. Nineteen recreationally active males were divided into CT (n = 11) and ST (n = 8) groups. The CT group performed repeated 1 min efforts at 100% of maximal aerobic speed interspersed by 1 min of passive recovery until accumulating a total running distance of 5km followed by a strength session (consisting of three sets of seven exercises with loads of 8-12 repetition maximum) twice weekly for a period of 12 weeks. The ST group performed only strength training sessions during the same 12-week period. Strength training total volume-load (Σ repetitions x load) for the upper- and lower-body was computed, while maximal strength (1RM) was evaluated at baseline, week 8, and week 12. Lower-body volume-load over 12 weeks was not different between groups. Absolute 1RM increased in both groups at week 8 and week 12, while 1RM relative to body mass increased in both groups at week 8, but only ST increased relative maximum strength between week 8 and week 12. There was a statistically significant correlation between strength training lower-body volume-load and maximum strength change between baseline and week 8 for the CT group (r = 0.656), while no significant correlations were found for the ST group. In summary, executing high-intensity intermittent exercise twice a week before strength training did not impair maximal strength after 8 weeks, however, only ST demonstrated an increase in relative strength after 12 weeks.

Is Oxygen Uptake Measurement Enough to Estimate Energy Expenditure During High-Intensity Intermittent Exercise? Quantification of Anaerobic Contribution by Different Methods.

Purpose: The aim of the present study was to compare the contributions of the anaerobic pathway as determined by two different methods and energy expenditure during a typical high-intensity intermittent exercise (HIIE) protocol. Methods: A descriptive research design was utilized in which thirteen physically active men performed six experimental sessions consisting of an incremental test (session 1), submaximal tests at 40, 50, 60, 70, 75, 80, 85, 90% of velocity associated with maximum oxygen uptake (v V˙ O2max) with two intensities per session (sessions 2-5), and the HIIE protocol (session 6; 10 efforts of 1 min at v V˙ O2max interspersed by 1 min of passive recovery). The estimation of anaerobic energy system contribution was calculated by: (a) the excess post-exercise oxygen consumption plus delta lactate method and (b) the accumulated oxygen deficit method using the difference between predicted oxygen demand from the submaximal tests of varying intensities and accumulated oxygen uptake during HIIE. Estimation of aerobic energy system contribution was calculated through the measurement of oxygen consumption during activity. Total EE during the entire HIIE protocol (efforts + recovery) and for the efforts only were calculated from each method. Results: For efforts + recovery and efforts only, anaerobic contribution was similar for both methods, and consequently total EE was also equivalent (p = 0.230 for both comparisons). During efforts + recovery, aerobic:anaerobic energy system contribution was (68 ± 4%: 32 ± 4%), while efforts only was (54 ± 5%: 46 ± 5%) with both situations demonstrating greater aerobic than anaerobic contribution (p < 0.001 for both). Conclusion: Anaerobic contribution seems to be relevant during HIIE and must to be taken into account during total EE estimation; however, the type of method employed did not change the anaerobic contribution or total EE estimates.

Reduced leptin level is independent of fat mass changes and hunger scores from high-intensity intermittent plus strength training.

BACKGROUND: This study aimed to analyze the effects of high-intensity intermittent training (HIIT) plus strength training on body composition, hormone related to energy balance (leptin), and hunger scores in physically active non-obese men. METHODS: Sixteen men were allocated in two different groups, training group (N.=10) performed a combined HIIT (5 km, 1 minute of effort interspersed by 1 minute of rest in passive recovery) followed by strength exercise session (three sets, with load of 8-12 repetition maximum) twice a week, during 8 weeks, while control group (N.=6) did not suffer any intervention. Hunger scores, leptin concentrations and body composition were assessed. Body composition, fasting leptin and hunger score were compared through two-way analysis (group and period) with repeated measures in the second factor while leptin and hunger scores in exercise session pre- and post-8 weeks through two-way analysis (period and time of measurement) with repeated measures in the second factor. RESULTS: The fasting leptin decreased pre- to post-8week in training group (7.7±4.9 to 2.9±2.1 ng/mL; P=0.012). For leptin response to exercise session there was main effect of training period, with higher values pre- (6.5±3.9 ng/mL) than post-training (2.6±2.1 ng/mL; P<0.001). For hunger scores there was effect of time of measurement (P<0.001), decreasing after breakfast and increasing over the experiment. CONCLUSIONS: Combined HIIT plus strength training were able to promote alterations in a hormone related to energy balance independent of body composition and hunger index alterations in physically active non-obese men.

Short-Term High- and Moderate-Intensity Training Modifies Inflammatory and Metabolic Factors in Response to Acute Exercise.

Purpose: To compare the acute and chronic effects of high intensity intermittent training (HIIT) and steady state training (SST) on the metabolic profile and inflammatory response in physically active men. Methods: Thirty recreationally active men were randomly allocated to a control group (n = 10), HIIT group (n = 10), or SST group (n = 10). For 5 weeks, three times per week, subjects performed HIIT (5 km 1-min at 100% of maximal aerobic speed interspersed by 1-min passive recovery) or SST (5 km at 70% of maximal aerobic speed) while the control group did not perform training. Blood samples were collected at fasting (~12 h), pre-exercise, immediately post, and 60 min post-acute exercise session (pre- and post-5 weeks training). Blood samples were analyzed for glucose, non-ester fatty acid (NEFA), and cytokine (IL-6, IL-10, and TNF-α) levels through a three-way analysis (group, period, and moment of measurement) with repeated measures in the second and third factors. Results: The results showed an effect of moment of measurement (acute session) with greater values to TNF-α and glucose immediately post the exercise when compared to pre exercise session, independently of group or training period. For IL-6 there was an interaction effect for group and moment of measurement (acute session) the increase occurred immediately post-exercise session and post-60 min in the HIIT group while in the SST the increase was observed only 60 min post, independently of training period. For IL-10, there was an interaction for training period (pre- and post-training) and moment of measurement (acute session), in which in pre-training, pre-exercise values were lower than immediately and 60 min post-exercise, in post-training period pre-exercise values were lower than immediately post-exercise and immediately post-exercise lower than 60 min post, it was also observed that values immediately post-exercise were lower pre- than post-training, being all results independently of intensity (group). Conclusion: Our main result point to an interaction (acute and chronic) for IL-10 showing attenuation post-training period independent of exercise intensity.

Physiological Acute Response to High-Intensity Intermittent and Moderate-Intensity Continuous 5 km Running Performance: Implications for Training Prescription.

The aim of this study was to investigate the physiological responses to moderate-intensity continuous and high-intensity intermittent exercise. Twelve physically active male subjects were recruited and completed a 5-km run on a treadmill in two experimental sessions in randomized order: continuously (70% sVO2max) and intermittently (1:1 min at sVO2max). Oxygen uptake, excess post-exercise oxygen consumption, lactate concentration, heart rate and rating of perceived exertion data were recorded during and after each session. The lactate levels exhibited higher values immediately post-exercise than at rest (High-Intensity: 1.43 ± 0.25 to 7.36 ± 2.78; Moderate-Intensity: 1.64 ± 1.01 to 4.05 ± 1.52 mmol⋅L-1, p = 0.0004), but High-Intensity promoted higher values (p = 0.001) than Moderate-Intensity. There was a difference across time on oxygen uptake at all moments tested in both groups (High-Intensity: 100.19 ± 8.15L; Moderate-Intensity: 88.35 ± 11.46, p < 0.001). Both exercise conditions promoted increases in excess postexercise oxygen consumption (High-Intensity: 6.61 ± 1.85 L; Moderate-Intensity: 5.32 ± 2.39 L, p < 0.005), but higher values were observed in the High-Intensity exercise protocol. High-Intensity was more effective at modifying the heart rate and rating of perceived exertion (High-Intensity: 183 ± 12.54 and 19; Moderate-Intensity: 172 ± 8.5 and 16, respectively, p < 0.05). In conclusion, over the same distance, Moderate-Intensity and High-Intensity exercise exhibited different lactate concentrations, heart rate and rating of perceived exertion. As expected, the metabolic contribution also differed, and High-Intensity induced higher energy expenditure, however, the total duration of the session may have to be taken into account. Moreover, when following moderate-intensity training, the percentage of sVO2max and the anaerobic threshold might influence exercise and training responses.