Effectiveness of m-health-based core strengthening exercise and health education for public safety workers with chronic non-specific low back pain: study protocol for a superiority randomized controlled trial (SAFEBACK).

BACKGROUND: Low back pain (LBP) is the leading cause of years lived with disability worldwide. Public safety workers are highly exposed to physically demanding activities and inappropriate postures, increasing the risk of experiencing LBP. Smartphone app-based self-managed interventions may be an alternative for chronic non-specific LBP (CNSLBP) treatment. This study aims to evaluate the effectiveness of a smartphone app-based self-managed exercise program plus health education, compared to a health education program alone, on neuromuscular and perceptual outcomes in police officers and firefighters with CNSLBP. METHODS: This is a parallel, two-armed, blinded evaluator randomized clinical trial. Police officers and firefighters (from public safety institutions in the Rio Grande do Sul state, Brazil) will be randomly assigned to a m-health self-managed exercise program (twice a week) plus health education or health education alone. Self-management exercise program components are mobility and core resistance exercises, available on the app. Follow-ups will be conducted post-treatment (8 weeks) and 16 weeks after randomization. The co-primary outcomes will be pain intensity and disability post-treatment (8 weeks). Secondary outcomes will be biopsychosocial factors related to CNSLBP. DISCUSSION: We hypothesize that the effects of a smartphone app-based self-managed exercise program on co-primary and secondary outcomes will be superior, compared to the health education only in public safety workers with CNSLBP. TRIAL REGISTRATION: The study was prospectively registered at ClinicalTrials.gov (NCT05481996. Registered on August 01, 2022).

Energy demands in high-intensity intermittent taekwondo specific exercises.

Background: Taekwondo is an intermittent Olympic combat sport, which shows an aerobic predominance in matches and high participation of alactic metabolism for actions that determine competitive success. However, there is no information on energetic contribution systems in different high-intensity intermittent exercises for metabolic conditioning with specific movements. The study aimed to measure the physiological demands, mainly the energy expenditure, in taekwondo-specific high-intensity intermittent exercises (HIIE). Methods: This study recruited ten male black belt athletes with a mean age of 20.2 ± 4 years, body mass of 62.8 ± 10.5 kg and height of 170.6 ± 7.8 cm, and total practice time of 11.8 ± 5.4 years. Subjects performed an incremental specific test and three different HIIE protocols on nonconsecutive days, and all comprised three 2-min rounds and 1 min of recovery between rounds. Heart rate, oxygen consumption, and blood lactate were measured. Energetic expenditure of aerobic, alactic, and lactic metabolisms was estimated through oxygen consumption, excess post-exercise oxygen consumption, and peak blood lactate after each round. Results: For the mean of the three rounds, the TKDtest100 resulted in higher absolute and relative contribution from the aerobic metabolism (52.4 ± 4%; p = 0.01) and lower than the 35:5 relative alactic contribution (48.7 ± 5.4%; p = 0.03). Conclusion: The mean of the three rounds for 35:5 and 15:10:5 presented similar absolute and relative contributions of aerobic and alactic metabolisms, whereas the TKDtest100 was a predominantly aerobic activity. We emphasize that aerobic metabolism was predominant from the second round in the 15:10:5 and 100%TKDtest protocols and in the last round of the 35:5 protocol.

Postexercise hypotension in men with parental history of hypertension: effects of mode and intensity.

BACKGROUND: A family history of arterial hypertension is a significant risk factor for the development of hypertension in youngsters. Thus, primary prevention has been emphasized in those subjects with a genetic predisposition. METHODS: This randomized clustered trial aimed to compare the effects of four modalities of aerobic training in postexercise hypotension. The primary outcomes were systolic blood pressure (SBP) and diastolic blood pressure (DBP). Secondly, peak oxygen uptake, heart rate, and subjective perceived exertion were analyzed. Nine normotensive men were randomized in four isocaloric sessions (200 kcal): high-intensity continuous training (HICT), moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), and moderate-intensity interval training (MIIT). RESULTS: The area under the curve (AUC) showed a difference between sessions for SBP (F(3;8)=3.2; P=0.04), with MICT promoting a higher reduction than MIIT (P<0.05). In DBP there was also a difference (F(3;8)=15.3; P<0.001), with HICT reducing more than HIIT (P<0.05) and MIIT (P<0.05). Moderate-intensity protocols provided clinically relevant changes (CRC) in 11.1% of the individuals, and high-intensity protocols presented CRC in 50% of them (χ2=6.41; P=0.011) for SBP. For DBP, there was CRC in 27.8% of continuous conditions and none in the intervals (χ2=5.81; P=0.016). CONCLUSIONS: All training sessions promoted postexercise hypotension for DBP, and HICT provided higher reductions in the AUC. CRC for SBP were observed according to the intensity, while CRC for DBP were associated with modality.

Kinematic Comparison of the Roundhouse Kick Between Taekwondo, Karate, and Muaythai.

ABSTRACT: Diniz, R, Del Vecchio, FB, Schaun, GZ, Oliveira, HB, Portella, EG, da Silva, ES, Formalioni, A, Campelo, PCC, Peyré-Tartaruga, LA, and Pinto, SS. Kinematic comparison of the roundhouse kick between taekwondo, karate, and muaythai. J Strength Cond Res 35(1): 198-204, 2021-The roundhouse kick (RHK) is frequently executed in taekwondo, karate, and muaythai because of its high technical effectiveness during combat. The purpose of this study was to compare kinematic characteristics during RHK performance between taekwondo, karate, and muaythai athletes. Forty-seven male athletes (25.5 ± 4.7 years, 1.75 ± 0.1 m, and 75.8 ± 11.5 kg) volunteered to participate (taekwondo: 17; karate: 15; and muaythai: 15). Self-selected distance from target, mean and peak fifth metatarsus linear velocity (LV5mean; LV5peak), mean and peak hip (HAVmean; HAVpeak) and knee (KAVmean; KAVpeak) angular velocities, as well as target linear acceleration (TLA) were analyzed with a 3D video motion analysis system. Comparisons between modalities were performed with 1-way analysis of variances and Bonferroni's post hoc test (α = 0.05). Self-selected distance was lower in muaythai compared with taekwondo and karate (p < 0.001). Also, karate had greater LV5mean compared with muaythai (p = 0.001), and muaythai showed higher HAVmean than karate (p = 0.011). In addition, HAVpeak was greater in muaythai than in taekwondo and karate (p < 0.001). No differences were found for KAVmean, KAVpeak, and TLA. Although it is similarly described between modalities, RHK showed distinct kinematic characteristics between taekwondo, karate, and muaythai. Based on these results, coaches and athletes can improve their RHK technique according to the specificities of each combat sport. Specifically, it is suggested that combat strategies should aim to increase the distance from the opponent during combat for muaythai athletes, whereas taekwondo and karate athletes should focus on decreasing it.

Physiological aspects and energetic contribution in 20s:10s high-intensity interval exercise at different intensities.

BACKGROUND: One of the most popular high-intensity interval exercises is the called "Tabata Protocol". However, most investigations have limitations in describing the work intensity, and this fact appears to be due to the protocol unfeasibility. Furthermore, the physiological demands and energetic contribution during this kind of exercise remain unclear. METHODS: Eight physically active students (21.8 ± 3.7 years) and eight well-trained cycling athletes (27.8 ± 6.4 years) were enrolled. In the first visit, we collected descriptive data and the peak power output (PPO). On the next three visits, in random order, participants performed interval training with the same time structure (effort:rest 20s:10s) but using different intensities (115%, 130%, and 170% of PPO). We collected the number of sprints, power output, oxygen consumption, blood lactate, and heart rate. RESULTS: The analysis of variance for multivariate test (number of sprints, power output, blood lactate, peak heart rate and percentage of maximal heart rate) showed significant differences between groups (F = 9.62; p = 0.001) and intensities (F = 384.05; p < 0.001), with no interactions (F = 0.94; p = 0.57). All three energetic contributions and intensities were different between protocols. The higher contribution was aerobic, followed by alactic and lactic. The aerobic contribution was higher at 115%PPO, while the alactic system showed higher contribution at 130%PPO. In conclusion, the aerobic system was predominant in the three exercise protocols, and we observed a higher contribution at lower intensities.

Effects of High-Intensity Interval Training in Combat Sports: A Systematic Review with Meta-Analysis.

Vasconcelos, BB, Protzen, GV, Galliano, LM, Kirk, C, and Del Vecchio, FB. Effects of high-intensity interval training in combat sports: A systematic review with meta-analysis. J Strength Cond Res 34(3): 888-900, 2020-Combat sports (CS) are intermittent by nature and high-intensity interval training (HIIT) has been used as a tool to maintain and improve physical fitness among CS athletes. The aim of this study was to perform a systematic review and meta-analysis about chronic effects of HIIT in CS athletes. An electronic search was performed in PubMed, Science Direct, and Google Scholar using the following Boolean criteria: ("CS" OR "martial arts" OR "judo" OR "taekwondo" OR "jiu jitsu" OR "boxing" OR "karate" OR "wrestling" OR "wushu" OR "kung fu") AND ("HIIT" OR "intermittent exercise" OR "sprint interval training" OR "repeated sprint training [RST]"). To be included, the studies needed to be original, involve CS athletes, present HIIT intervention protocol (HIIT, sprint interval training [SIT] or RST), and analyze chronic physiological outcomes. From 2,211 identified studies, after screening and eligibility evaluation, 12 studies were included in this review with meta-analysis. Aerobic (aerobic capacity, heart rate, and maximum oxygen uptake), anaerobic (peak and mean power in single and successive Wingate tests, and blood lactate concentration), and anthropometric outcomes (body mass and body fat percentage) were evaluated. Data of 255 subjects from 12 studies were assessed. Regarding methodological quality, 7 studies obtained 9-10/12 on the TESTEX scale. For the interventions, 5 studies used HIIT, 4 studies used RST protocols, one used SIT protocols, and one used an intermittent protocol that could not be classified. Relating to aerobic power, was found an increase in V[Combining Dot Above]O2max, with a mean difference (MD) of 2.83 ml·kg·min (CI 95% = 0.40-5.25; p < 0.001) for striking and 2.36 ml·kg·min (CI 95% = 1.05-3.66; p < 0.001) for grappling athletes. No differences on anaerobic peak power for striking (MD = 0.67 W; CI 95% = -0.43 to 1.77; p = 0.23) were found, and a statistical improvement for grappling athletes, (MD = 0.51 W; CI 95% = 0.03-0.98; p = 0.04) was found. Seven studies analyzed anthropometric variables, with differences for body mass in striking (MD = -0.93 kg; CI 95% = -1.68 to -0.19; p = 0.01) and no differences for grappling (MD = -0.09 kg; CI 95% = -2.80 to 2.62; p = 0.95). Differences in body fat percentage in striking (MD = 0.50%; CI 95% = 0.30-0.70; p < 0.001) and no differences in grappling (MD = -0.87%; CI 95% = -1.77 to 0.03; p = 0.06) were found. It was concluded that HIIT positively influences maximum oxygen uptake and anaerobic power in combat sport athletes, with a minor impact on body composition.

Supplementation with beta-hydroxy-beta-methylbutyrate impacts glucose homeostasis and increases liver size in trained mice.

ß-hydroxy-ß-methyl butyrate (HMB) is a bioactive metabolite derived from the amino acid leucine, usually applied for muscle mass increase during physical training, as well as for muscle mass maintenance in debilitating chronic diseases. The hypothesis of the present study is that HMB is a safe supplement for muscle mass gain by strength training. Based on this, the objective was to measure changes in body composition, glucose homeostasis and hepatic metabolism of HMB supplemented mice during strength training. Two of four groups of male mice (n = 6/group) underwent an 8-week training period session (climbing stairs) with or without HMB supplementation (190 mg/kgBW per day). We observed lower body mass gain (4.9 ± 0.43% versus 1.2 ± 0.43, p < 0.001) and increased liver mass (40.9 ± 0.9 mg/gBW versus 44.8 ± 1.3, p < 0.001) in the supplemented trained group compared with the non-supplemented groups. The supplemented trained group had an increase in relative adipose tissue mass (12.4 ± 0.63 mg/gBW versus 16.1 ± 0.88, P < 0.01) compared to the non-supplemented untrained group, and an increase in fasting blood glucose (111 ± 4.58 mg/dL versus 122 ± 3.70, P < 0.05) and insulin resistance (3.79 ± 0.19 % glucose decay/min versus 2.45 ± 0.28, P < 0.05) comparing with non-supplemented trained group. Adaptive heart hypertrophy was observed only in the non-supplemented trained group (4.82 ± 0.05 mg/gBW versus 5.12 ± 0.13, P < 0.05). There was a higher hepatic insulin-like growth factor-1 expression (P = 0.002) in supplemented untrained comparing with non-supplemented untrained group. Gene expression of gluconeogenesis regulatory factors was increased by training and reduced by HMB supplementation. These results confirm that HMB supplementation associated with intensive training protocol drives changes in glucose homeostasis and liver metabolism in mice.

Psychophysiological profile and prediction equations for technical performance of football players / Perfil psicofisiológico e equações preditivas de desempenho técnico em jogadores de futebol / Perfil psicofisiológico y ecuaciones predictivas de rendimiento técnico de jugadores de fútbol

Abstract The objective was to correlate specific technical skills (STS) with the psychophysiological performance. STS from 15 soccer athletes were collected by technical scouting of two matches. Countermovement jump, blood concentration of creatine kinase ([CK]), heart rate variability (HRV) and the scores of DALDA and POMS were also obtained 24 h after both matches. Predictive equations were elaborated, and POMS and DALDA scores were the only variables which fits the models for STS with high coefficient of determination (r2) for finalization (r2 = 0.85), interception (r2 = 0.73), pass right (r2 = 0.32), tackling (r2 = 0.69) and loss of ball (r2 = 0.35). The psychological variables identified through POMS and DALDA have shown greater influence on the STS.

Resumo O objetivo foi correlacionar variáveis psicofisiológicas com desempenho técnico específico (STS). As STS foram coletadas durante dois jogos amistosos através de scout técnico. Salto contramovimento, concentração sanguínea de creatina quinase ([CK]), variabilidade da frequência cardíaca (HRV) e os escores de POMS e DALDA também foram acessados. Equações preditivas foram testadas e os escores de POMS e DALDA formaram modelos de regressão com significância estatística e coeficiente de determinação (r2) expressivo para as STS de finalização (r2 = 0,85), interceptação (r2 = 0,73), passe certo (r2 = 0,32), roubada de bola (r2 = 0,69) e perda de posse de bola (r2 = 0,35). Variáveis psicológicas foram capazes de predizer o desempenho técnico em STS coletadas em scout de partidas de futebol.

Resumen El objetivo fue correlacionar habilidades técnicas específicas (STS) con evaluaciones psicofisiológicas. Las STS de 15 jugadores de fútbol se recogieron mediante técnica de scouting de dos partidos. Salto contramovimiento, concentración sanguínea de creatina-cinasa, variabilidad de la frecuencia cardíaca y las puntuaciones de DALDA y POMS se obtuvieron 24 h después de ambos partidos. Se elaboraron ecuaciones predictivas y POMS y DALDA se ajustaron a los modelos con alto coeficiente de determinación (r2) para finalización (r2 = 0,85), interceptación (r2 = 0,73), pase correcto (r2 = 0,32), quite de balón (r2 = 0,69) y pérdida de balón (r2 = 0,35). Las variables psicológicas identificadas a través de POMS y DALDA han mostrado gran influencia en las STS.

Characterization of the Physical Fitness of Police Officers: A Systematic Review.

Marins, EF, David, GB, and Del Vecchio, FB. Characterization of the physical fitness of police officers: a systematic review. J Strength Cond Res 33(10): 2860-2874, 2019-Physical fitness tests (e.g., aerobic power, muscular endurance, and flexibility tests) are commonly used to assess the ability of police officers to perform work-related tasks. The purpose of this study was to describe, from a systematic literature review, data related to police physical fitness. The research was conducted in 5 electronic databases to search for original studies that measured physical fitness (aerobic and anaerobic capacity, strength, endurance, power, flexibility, agility, and speed) of police officers, as well as the article references. Original studies assessing objective measures of physical fitness in police officers were included, with no date restriction. Fifty-nine articles were included in the review. The studies mostly measured cardiorespiratory fitness indirectly, strength, and muscular endurance, as well as other performance components (body composition, power, flexibility, speed, agility, and anaerobic profile), with police officers generally presenting values similar or above the average of the general population. It can be concluded that intervention studies are needed to promote and incorporate programs related to improvement or maintenance of physical fitness in police officers, which would result in health benefits and specifically improvement in performance of specific tasks of police work. This review provides summary information to assist in the selection of physical fitness tests for police populations. Still, these findings have practical applications for public security agencies and its personnel responsible for the development and implementation of physical programs in policemen population.

A 12-Year Cohort Study of Doc-Stoppage in Professional Mixed Martial Arts.

Purposes: To determine actions during bouts that generate serious enough injury to stop the bout; verifying the injury incidence, types, and prevalence of doctor stoppages (doc-stoppage); and identify potential risk factors by analyzing technical-tactical profiles for injury in sanctioned mixed martial arts bouts taking place over a 12-y period. Methods: This research analyzed 440 paired mixed martial arts matches separated by doc-stoppage (n = 220) and no doc-stoppage (n = 220) from 2002 to 2014. Technical knockouts for doc-stoppage were diagnosed and managed by attending ringside doctors, and the time-motion variables were categorized into total combat time separated by low- or high-intensity activities per round, stand-up, or groundwork actions, P ≤ .05. Results: The main cause of injuries in doc-stoppage situations was due to facial injuries (>90%), with 87.1% occurring after striking actions during the second round. Lacerations were the leading type of injury, which occurred with 80% frequency. The results showed differences between doc-stoppage and no doc-stoppage for standing combat with low-intensity actions (130.6 [8.5] s vs 83.3 [6.9] s for first round; 115.7 [10.5] s vs 100.1 [9.6] s for second round, and 121.5 [19.5] s vs 106.3 [11.7] s for third round) and total strike attempts (34.5, 23.0-51.8 vs 25.0, 12.0-40.8); in standing combat, head strike attempts (21, 10-33 vs 11, 4-21) and body strikes (2.5, 1.0-5.8 vs 1.0-2), and in groundwork combat, head strikes landed (0.0-3.0 vs 0.0-5.0). Conclusions: This research showed higher values of strike attempts with 2 main orientations, namely the head (on the ground and in stand-up actions) and body (in stand-up actions), and may provide important information regarding the technical knockout and when it can be called by officials supervising mixed martial arts bouts.

Physical activity level in women with gestational diabetes mellitus: Lifestyle INtervention for Diabetes prevention After pregnancy (LINDA-Brasil) study.

BACKGROUND: The aim of this study was to investigate physical activity and associated factors in women with gestational diabetes mellitus (GDM). METHODS: This cross-sectional study was performed on 2706 women as part of the Lifestyle INtervention for Diabetes prevention After pregnancy (LINDA-Brasil) study, recruited between 2012 and 2016 in Brazil. A structured questionnaire was used to assess physical activity. Descriptive and Poisson regression analyses were used to investigate physical activity and associated factors. RESULTS: Counseling regarding physical activity practices was reported by 47.4% and 34.3% of women before and after a diagnosis of GDM, respectively. During pregnancy, 26% of women were classified as inactive, 39.7% were classified as insufficiently active, and 34.3% were classified as active. Compared with prepregnancy, 63.1% of women reported a decrease in physical activity levels during pregnancy. The prevalence of being inactive during pregnancy was higher among women who did not live with a partner (P = 0.003), had a lower household income (P = 0.01), were employed (P < 0.001), and who had four or more children (P < 0.001). CONCLUSION: Among Brazilian women with GDM, physical activity levels and practices were low, with most women reporting decreased physical activity during pregnancy. A low socioeconomic status was associated with lower physical activity. These findings indicate the need to reinforce the importance of physical activity in the management of GDM in Brazil.

Physical fitness predicts technical-tactical and time-motion profile in simulated Judo and Brazilian Jiu-Jitsu matches.

BACKGROUND: Among combat sports, Judo and Brazilian Jiu-Jitsu (BJJ) present elevated physical fitness demands from the high-intensity intermittent efforts. However, information regarding how metabolic and neuromuscular physical fitness is associated with technical-tactical performance in Judo and BJJ fights is not available. This study aimed to relate indicators of physical fitness with combat performance variables in Judo and BJJ. METHODS: The sample consisted of Judo (n = 16) and BJJ (n = 24) male athletes. At the first meeting, the physical tests were applied and, in the second, simulated fights were performed for later notational analysis. RESULTS: The main findings indicate: (i) high reproducibility of the proposed instrument and protocol used for notational analysis in a mobile device; (ii) differences in the technical-tactical and time-motion patterns between modalities; (iii) performance-related variables are different in Judo and BJJ; and (iv) regression models based on metabolic fitness variables may account for up to 53% of the variances in technical-tactical and/or time-motion variables in Judo and up to 31% in BJJ, whereas neuromuscular fitness models can reach values up to 44 and 73% of prediction in Judo and BJJ, respectively. When all components are combined, they can explain up to 90% of high intensity actions in Judo. DISCUSSION: In conclusion, performance prediction models in simulated combat indicate that anaerobic, aerobic and neuromuscular fitness variables contribute to explain time-motion variables associated with high intensity and technical-tactical variables in Judo and BJJ fights.

Defining the number of bouts and oxygen uptake during the "Tabata protocol" performed at different intensities.

It is usually reported that the Tabata protocol (TP) is performed with eight bouts of 20:10 intervals at a load equivalent to 170% of i V̇ O2max. However, the feasibility of accumulating 160 s of work at 170% i V̇ O2max has been questioned. This article tested the intensity that would allow the performance of the original TP on a cycle ergometer, and measured the highest value of oxygen consumption (V̇ O2) obtained during the TP and the time spent above 90% of the maximal oxygen uptake (V̇ O2max) during the TP performed at different intensities. Thirteen young active males (25.9 ±â€¯5.5 years, 67.9 ±â€¯9.2 kg, 1.70 ±â€¯0.06 m, 23.6 ±â€¯3.1 kg·m-2) participated in the study. Participants performed a graded exertion test (GXT) on a cycle ergometer to obtain maximum oxygen consumption (V̇ O2max) and the intensity associated with V̇ O2max (i V̇ O2max). V̇ O2, maximal heart rate (HRmax), and number of bouts performed were evaluated during the TP performed at 115%, 130%, and 170% of i V̇ O2max. V̇ O2max, HRmax, and iV̇ O2max were 51.8 ±â€¯8.0 mL.kg-1·min-1, 186 ±â€¯10 bpm, and 204 ±â€¯26 W, respectively. The number of bouts performed at 115% (7 ±â€¯1 bouts) was higher than at 130% (5 ±â€¯1 bouts) and 170% (4 ±â€¯1 bouts) (p < .0001). The highest V̇ O2 achieved at 115%, 130%, and 170% of iV̇ O2max was 54.2 ±â€¯7.9 mL·kg-1·min-1, 52.5 ±â€¯8.1 mL·kg-1·min-1, and 49.6 ±â€¯7.5 mL·kg-1·min-1, respectively. Non significant difference was found between the highest V̇ O2 achieved at different intensities, however qualitative magnitude-inference indicate a likely small effect between 115% and 170% of iV̇ O2max. Time spent above 90% of the V̇ O2max during the TP at 115% (50 ±â€¯48 s) was higher than 170% (23 ±â€¯21 s; p < 0.044) with a probably small effect. In conclusion, our data suggest that the adequate intensity to perform a similar number of bouts in the original TP is lower than previously proposed, and equivalent to 115% of the iV̇ O2max. In addition, intensities between 115 and 130% of the iV̇ O2max should be used to raise the time spent above 90% V̇O2max.

High-Intensity Interval Exercises' Acute Impact on Heart Rate Variability: Comparison Between Whole-Body and Cycle Ergometer Protocols.

Schaun, GZ and Del Vecchio, FB. High-intensity interval exercises' acute impact on heart rate variability: comparison between whole-body and cycle ergometer protocols. J Strength Cond Res 32(1): 223-229, 2018-Study aimed to compare the effects of 2 high-intensity interval training (HIIT) protocols on heart rate variability. Twelve young adult males (23.3 ± 3.9 years, 177.8 ± 7.4 cm, 76.9 ± 12.9 kg) volunteered to participate. In a randomized cross-over design, subjects performed 2 HIIT protocols, 1 on a cycle ergometer (Tabata protocol [TBT]; eight 20-second bouts at 170% Pmax interspersed by 10-second rest) and another with whole-body calisthenic exercises (McRae protocol; eight 20-second all-out intervals interspersed by 10-second rest). Heart rate variability outcomes in the time, frequency, and nonlinear domains were assessed on 3 moments: (a) presession; (b) immediately postsession; and (c) 24 hours postsession. Results revealed that RRmean, Ln rMSSD, Ln high frequency (HF), and Ln low frequency (LF) were significantly reduced immediately postsession (p ≤ 0.001) and returned to baseline 24 h after both protocols. In addition, LF/HF ratio was reduced 24 h postsession (p ≤ 0.01) and SD2 was significantly lower immediately postsession only in TBT. Our main finding was that responses from heart rate autonomic control were similar in both protocols, despite different modes of exercise performed. Specifically, exercises resulted in a high parasympathetic inhibition immediately after session with subsequent recovery within 1 day. These results suggest that subjects were already recovered the day after and can help coaches to better program training sessions with such protocols.

Intervenções com promoção de atividade física na prevenção primária do diabetes: Metanálise / Intervention with physical activity promotion in primary prevention of diabetes: Meta-analysis

Introdução: Estudos de intervenções com prática de atividade física (AF) e aconselhamento nutricional para indivíduos com risco de desenvolverem diabetes mellitus (DM) têm sido elaborados, mas a síntese de tais estudos ainda é restrita. Objetivo: Reunir e calcular a força de evidência dos achados da última década sobre promoção de AF e prevenção do DM, com base em estudos de intervenção bem delineados e com alta qualidade metodológica com adultos em risco de desenvolver DM. Métodos: Conduziu-se metanálise considerando publicações de 2001 a setembro de 2014. Para pesquisa das referências, foram utilizados os seguintes descritores: diabetes mellitus, intervenção, "atividade física", "exercício físico", organizados adequadamente e em diferentes combinações. Resultados: Foi encontrada redução de 2,13 mmol/L (IC95% = 1,62-2,64; p<0,0001) nos níveis glicêmicos dos sujeitos acompanhados. Conclusão: Intervenções com atividade física exerceram efeitos positivos na prevenção ou retardamento de DM em pessoas com risco de desenvolvê-la.

Introduction: Studies of interventions with physical activity (PA) and nutritional counseling to individuals at risk of developing diabetes mellitus (DM) have been prepared, but the synthesis of such studies is still limited. Objective: To collect and calculate the strength of evidence from the past decade findings on the promotion of PA and prevention of DM, based on well-designed intervention studies with high methodological quality to adults at risk of developing diabetes. Methods: A meta-analysis was conducted considering publications from 2001 to September 2014. To the references search, the following descriptors were used: "diabetes mellitus", "intervention", "physical activity", "physical exercise", organized properly and in different combinations. Results: We found decrease of 2.13mmol/L (95% CI = 1.62 to 2.64; p <0.0001) in blood glucose levels in monitored subjects. Conclusion: Interventions with PA exerted positive effects in the prevention or delay of DM in people at risk of developing this disease.

Time-Motion and Biological Responses in Simulated Mixed Martial Arts Sparring Matches.

Coswig, VS, Ramos, SdP, and Del Vecchio, FB. Time-motion and biological responses in simulated mixed martial arts sparring matches. J Strength Cond Res 30(8): 2156-2163, 2016-Simulated matches are a relevant component of training for mixed martial arts (MMA) athletes. This study aimed to characterize time-motion responses and investigate physiological stress and neuromuscular changes related to MMA sparring matches. Thirteen athletes with an average age of 25 ± 5 years, body mass of 81.3 ± 9.5 kg, height of 176.2 ± 5.5 cm, and time of practice in MMA of 39 ± 25 months participated in the study. The fighters executed three 5-minute rounds with 1-minute intervals. Blood and salivary samples were collected and physical tests and psychometric questionnaires administered at 3 time points: before (PRE), immediately after (POST), and 48 hours after the combat (48 h). Statistical analysis applied analysis of variance for repeated measurements. In biochemical analysis, significant changes (p ≤ 0.05) were identified between PRE and POST (glucose: 80.3 ± 12.7 to 156.5 ± 19.1 mg·ml; lactate: 4 ± 1.7 to 15.6 ± 4.8 mmol·dl), POST and 48 hours (glucose: 156.5 ± 19.1 to 87.6 ± 15.5 mg·ml; lactate: 15.6 ± 4.8 to 2.9 ± 3.5 mmol·dl; urea: 44.1 ± 8.9 to 36.3 ± 7.8 mg·ml), and PRE and 48 hours (creatine kinase [CK]: 255.8 ± 137.4 to 395.9 ± 188.7 U/L). In addition, time-motion analyses showed a total high:low intensity of 1:2 and an effort:pause ratio of 1:3. In conclusion, simulated MMA sparring matches feature moderate to high intensity and a low degree of musculoskeletal damage, which can be seen by absence of physical performance and decrease in CK. Results of the study indicate that sparring training could be introduced into competitive microcycles to improve technical and tactical aspects of MMA matches, due to the high motor specificity and low muscle damage.

Effects of Plyometric Training on Physical Fitness in Team Sport Athletes: A Systematic Review.

Plyometric training (PT) is a very popular form of physical conditioning of healthy individuals that has been extensively studied over the last decades. In this article, we critically review the available literature related to PT and its effects on physical fitness in team sport athletes. We also considered studies that combined PT with other popular training modalities (e.g. strength/sprint training). Generally, short-term PT (i.e. 2-3 sessions a week for 4-16 weeks) improves jump height, sprint and agility performances in team sport players. Literature shows that short PT (<8 weeks) has the potential to enhance a wide range of athletic performance (i.e. jumping, sprinting and agility) in children and young adult amateur players. Nevertheless, 6 to 7 weeks training appears to be too short to improve physical performance in elite male players. Available evidence suggests that short-term PT on non-rigid surfaces (i.e. aquatic, grass or sand-based PT) could elicit similar increases in jumping, sprinting and agility performances as traditional PT. Furthermore, the combination of various plyometric exercises and the bilateral and unilateral jumps could improve these performances more than the use of single plyometric drills or traditional PT. Thus, the present review shows a greater effect of PT alone on jump and sprint (30 m sprint performance only) performances than the combination of PT with sprint/strength training. Although many issues related to PT remain to be resolved, the results presented in this review allow recommending the use of well-designed and sport-specific PT as a safe and effective training modality for improving jumping and sprint performance as well as agility in team sport athletes.