Effects of Inspiratory Muscle Warm-Up on Physical Exercise: A Systematic Review.

This study aimed to systematically review the literature to examine the effects of inspiratory-muscle warm-up (IMW) on the inspiratory, metabolic, respiratory and performance parameters of a main exercise performed by athletes and healthy and active individuals. Methods: This systematic review included randomized studies in English based on the criteria of the PICOS model. The exclusion criteria adopted were studies that applied inspiratory exercise to: i. promote long-term adaptations through inspiratory training (chronic responses); ii. obtain acute responses to inspiratory load (overload) during and in breaks from physical effort and in an inspiratory-exercise session (acute training effect); iii. evaluate the effects of IMW on participants with cardiorespiratory and/or metabolic disease. Data Sources: PubMed, Embase, MedLine, Scopus, SPORTDiscus and Google Scholar (until 17 January 2023). Results: Thirty-one studies were selected. The performance and respiratory parameters were the most investigated (77% and 74%, respectively). Positive effects of IMW were reported by 88% of the studies that investigated inspiratory parameters and 45% of those that evaluated performance parameters. Conclusions: The analyzed protocols mainly had positive effects on the inspiratory and performance parameters of the physical exercises. These positive effects of IMW are possibly associated with the contractile and biochemical properties of inspiratory muscles.

Effects of different inspiratory muscle warm-up loads on mechanical, physiological and muscle oxygenation responses during high-intensity running and recovery.

Inspiratory muscle warm-up (IMW) has been used as a resource to enhance exercises and sports performance. However, there is a lack of studies in the literature addressing the effects of different IMW loads (especially in combination with a shorter and applicable protocol) on high-intensity running and recovery phase. Thus, this study aimed to investigate the effects of three different IMW loads using a shorter protocol on mechanical, physiological and muscle oxygenation responses during and after high-intensity running exercise. Sixteen physically active men, randomly performed four trials 30 s all-out run, preceded by the shorter IMW protocol (2 × 15 breaths with a 1-min rest interval between sets, accomplished 2 min before the 30 s all-out run). Here, three IMW load conditions were used: 15%, 40%, and 60% of maximal inspiratory pressure (MIP), plus a control session (CON) without the IMW. The force, velocity and running power were measured (1000 Hz). Two near-infrared spectroscopy (NIRS) devices measured (10 Hz) the muscle's oxygenation responses in biceps brachii (BB) and vastus lateralis (VL). Additionally, heart rate (HR) and blood lactate ([Lac]) were also monitored. IMW loads applied with a shorter protocol promoted a significant increase in mean and minimum running power as well as in peak and minimum force compared to CON. In addition, specific IMW loads led to higher values of peak power, mean velocity (60% of MIP) and mean force (40 and 60% of MIP) in relation to CON. Physiological responses (HR and muscles oxygenation) were not modified by any IMW during exercise, as well as HR and [Lac] in the recovery phase. On the other hand, 40% of MIP presented a higher tissue saturation index (TSI) for BB during recovery phase. In conclusion, the use of different loads of IMW may improve the performance of a physically active individual in a 30 s all-out run, as verified by the increased peak, mean and minimum mechanical values, but not in performance assessed second by second. In addition, 40% of the MIP improves TSI of the BB during the recovery phase, which can indicate greater availability of O2 for lactate clearance.

Effect of Different Recoveries During HIIT Sessions on Metabolic and Cardiorespiratory Responses and Sprint Performance in Healthy Men.

ABSTRACT: Germano, MD, Sindorf, MAG, Crisp, AH, Braz, TV, Brigatto, FA, Nunes, AG, Verlengia, R, Moreno, MA, Aoki, MS, and Lopes, CR. Effect of different recoveries during HIIT sessions on metabolic and cardiorespiratory responses and sprint performance in healthy men. J Strength Cond Res 36(1): 121-129, 2022-The purpose of this study was to investigate how the type (passive and active) and duration (short and long) recovery between maximum sprints affect blood lactate concentration, O2 consumed, the time spent at high percentages of V̇o2max, and performance. Subjects were randomly assigned to 4 experimental sessions of high-intensity interval training exercise. Each session was performed with a type and duration of the recovery (short passive recovery-2 minutes, long passive recovery [LPR-8 minutes], short active recovery-2 minutes, and long active recovery [LAR-8 minutes]). There were no significant differences in blood lactate concentration between any of the recoveries during the exercise period (p > 0.05). The LAR presented a significantly lower blood lactate value during the postexercise period compared with LPR (p < 0.01). The LPR showed a higher O2 volume consumed in detriment to the active protocols (p < 0.001). There were no significant differences in time spent at all percentages of V̇o2max between any of the recovery protocols (p > 0.05). The passive recoveries showed a significantly higher effort time compared with the active recoveries (p < 0.001). Different recovery does not affect blood lactate concentration during exercise. All the recoveries permitted reaching and time spent at high percentages of V̇o2max. Therefore, all the recoveries may be efficient to generate disturbances in the cardiorespiratory system.

Complex network model indicates a positive effect of inspiratory muscles pre-activation on performance parameters in a judo match.

This study investigated the effects of inspiratory muscle pre-activation (IMPA) on the interactions among the technical-tactical, physical, physiological, and psychophysiological parameters in a simulated judo match, based on the centrality metrics by complex network model. Ten male athletes performed 4 experimental sessions. Firstly, anthropometric measurements, maximal inspiratory pressure (MIP) and global strenght of the inspiratory muscles were determined. In the following days, all athletes performed four-minute video-recorded judo matches, under three conditions: without IMPA (CON), after IMPA at 15% (IMPA15), and at 40% (IMPA40) of MIP using an exerciser device. Blood lactate, heart rate and rating of perceived exertion were monitored, and the technical-tactical parameters during the match were related to offensive actions and the time-motion. Based on the complex network, graphs were constructed for each scenario (CON, IMPA15, and IMPA40) to investigate the Degree and Pagerank centrality metrics. IMPA40 increased the connectivity of the physical and technical-tactical parameters in complex network and highlighted the combat frequency and average combat time in top-five ranked nodes. IMPA15 also favoured the interactions among the psychophysiological, physical, and physiological parameters. Our results suggest the positive effects of the IMPA, indicating this strategy to prepare the organism (IMPA15) and to improve performance (IMPA40) in judo match.

Excess Post-Exercise Oxygen Consumption and Substrate Oxidation Following High-Intensity Interval Training: Effects of Recovery Manipulation.

The recovery manipulation during high-intensity interval training (HIIT) may have the potential to modulate the responses of post-exercise energy metabolism. The purpose of this study was to investigate how the type (i.e., passive and active) and duration (i.e., short and long) of the recovery between the intervals in HIIT affect the excess post-exercise oxygen consumption (EPOC) and oxidation of fats and carbohydrates during the post-exercise recovery. Eight physically active men performed a maximal incremental test, to determine the peak oxygen consumption (V̇O2peak) and the first ventilatory threshold (VT), and four HIIT exercise sessions on a treadmill. The HIIT exercise sessions consisted of 5 intervals interspersed with 4 recovery periods; each interval was sustained until exhaustion, and the intensity was set at the V̇O2peak velocity; recoveries were passive, active (VT velocity), short (2-min), or long (8-min). The HIIT exercise sessions were performed in a random and crossed manner. After the HIIT exercise sessions, EPOC and oxidation of fats and carbohydrates were measured during the 120-min of post-exercise recovery. There were no differences in the EPOC among the exercise sessions (p = 0.56). There were no differences among the exercise sessions in the amount of energy expended on the oxidation of fats (p = 0.78) and carbohydrates (p = 0.91) during the post-exercise recovery. The recovery manipulation during HIIT does not affect the EPOC and post-exercise fat and carbohydrate oxidation. One can choose the type and duration of recovery, knowing that the post-exercise substrate oxidation and EPOC responses will be preserved.

Effects of Inspiratory Muscle Training With Progressive Loading on Respiratory Muscle Function and Sports Performance in High-Performance Wheelchair Basketball Athletes: A Randomized Clinical Trial.

PURPOSE: To evaluate the effects of inspiratory muscle training associated with interval training on respiratory muscle strength and fatigue and aerobic physical performance (PP) in high-performance wheelchair basketball athletes. METHODS: Blinded, randomized clinical trial with 17 male wheelchair basketball players, randomized into control group (CG; n = 8) and training group (TG; n = 9). Respiratory muscle strength was evaluated by measuring maximal inspiratory and expiratory pressures (MIP and MEP), aerobic PP by the Yo-Yo test for wheelchair, and recovery of inspiratory muscle fatigue was assessed at 1, 5, 10, and 15 minutes after exercise test. TG performed inspiratory muscle training protocol with incremental loading for 12 weeks with 50%, 60%, and 70% of MIP, while CG performed with load 15% of MIP. RESULTS: After training period, CG presented a significant increase in MIP and MEP (P ≤ .05), with no change in aerobic PP (P ≥ .05). TG showed a significant increase for all variables (≤.05). MIP showed a large effect size for CG (1.00) and TG (1.35), while MEP showed a moderate effect for CG (0.61) and TG (0.73); distance covered had a moderate effect size for TG (0.70). For recovery of inspiratory muscle strength, CG did not present differences, while TG recovered in 10 minutes (≤.05), representing 87% of the pretest value. Positive and significant correlation between MIP and distance (.54; P ≤ .05) was observed. CONCLUSION: Inspiratory muscle training protocol with progressive loading was more effective for increasing aerobic PP and maximal inspiratory strength recovery.

Relação da maturação biológica com variabilidade da frequência cardíaca e resistência intermitente de jovens futebolistas / Relationship of biological maturation with heart rate variability and intermittent resistance of young soccer players

O objetivo do estudo foi investigar a relação entre maturação biológica, modulação parassimpática da frequência cardíaca e teste de resistência intermitente em jovens jogadores de futebol. Participaram do estudo 23 jovens futebolistas (15,3 ± 1,1 anos, 175 ± 6 cm, 64 ± 7 kg) das categorias sub15 e sub17 de uma equipe da 1ª divisão do campeonato paulista. O estado maturacional foi determinado pela idade do pico de velocidade de crescimento (PVC), usado como indicador relativo de maturidade somática calculada através das medidas de estatura, altura tronco-cefálica, comprimento das pernas, massa corporal e as dobras cutâneas. As medidas de variabilidade da frequência cardíaca (VFC) foram obtidas em repouso durante 5 minutos e, posteriormente, analisadas pela variável raiz quadrada da média dos quadrados das diferenças entre intervalos RR normais adjacentes (rMSSD). Os indivíduos realizaram o teste de resistência intermitente, Yoyo intermittent recovery test level 2 (YIRT 2), após as medidas de VFC terem sido obtidas. Os resultados do presente estudo mostram que não há relação entre modulação parassimpática da frequência cardíaca (rMSSD = 57,4 ± 26,4 ms) e o estado de maturação biológica (0,67 ± 0,81 anos) dos jovens futebolistas (r= 0,30; p=0,163), enquanto que o teste de resistência intermitente (YIRT 2= 658 ± 151 m) possui uma grande correlação com o pico de velocidade de crescimento (r= 0,71; p< 0,001). A modulação parassimpática da frequência cardíaca possui grande correlação com o teste de resistência intermitente dos jogadores (r= 0,54; p= 0,007). Conclui-se que a utilização da idade do PVC e da VFC como indicador de desempenho no YIRT2 em jovens futebolistas....(AU)

The aim of the study was to investigate the relationship between biological maturation, parasympathetic heart rate modulation and intermittent endurance test in young soccer players. Participated of the study 23 young soccer players (15.3 ± 1.1 years, 175 ± 6 cm, 64 ± 7 kg) of the sub15 and sub17 categories of the team from the 1st division championship Paulista. The maturational status was determined by the age of the peak height velocity (PHV), used as relative indicator of somatic maturity and are calculated trhough measures of height, trunk-cephalic height, leg length, body weight, and skinfolds. The Heart rate variability (HRV) measures were obtained in rest during 5 minutes and, posteriorly, analyzed by the variable root mean square of the successive difference (rMSSD). For the intermittent endurance test the subjects performed the Yoyo intermittent recovery test level 2 (YIRT 2), before the HRV measures has been taken. The results of the present study shown which there was not relationship between parasympathetic heart rate modulation (rMSSD = 57,4 ± 26,4 ms) and status biological maturation (0,67 ± 0,81 years) of the young soccer players (r= 0,30; p=0,163), then that the intermittent endurance test (YIRT 2= 658 ± 151 m) has a great correlation with PHV (r= 0,71; p< 0,001). The parasympathetic heart rate modulation has a great correlation with intermittent endurance test of the players (r= 0,54; p= 0,007). In this way, the use of the PHV age and HRV as indicator of performance in YIRT2 in young soccer players is suggested....(AU)

Effect of Inspiratory Muscle Training on Performance of Handball Athletes.

Inspiratory muscle training (IMT) is a strategy that has been used to improve performance in different sports modalities. This study investigated the effects of an IMT program on respiratory muscle strength and resistance as well as aerobic physical performance (PP) of handball athletes. Nineteen 20 ± 3 year-old male athletes were allocated into an experimental (EG, n = 10) or a placebo group (PG, n = 9). Their respiratory muscle strength was evaluated by measuring the maximum inspiratory and expiratory pressures (MIP and MEP), muscular respiratory resistance by maximum voluntary ventilation (MVV) and aerobic PP by the cardiopulmonary exercise test. The study was designed to evaluate the effects of a 12-week IMT program with five sessions a week. A significant difference was observed in the pre and post IMT values of the MIP (170 ± 34 to 262 ± 33 cmH2O) and MEP (177 ± 36 to 218 ± 37 cmH2O) in the EG, and MIP (173 ± 45 to 213 ± 21 cmH2O) in the PG, with a large effect size for the MIP, when the groups were compared. MVV showed a significant increase (162 ± 24 to 173 ± 30 L) in the EG, with a small effect size. There was a significant difference in maximum oxygen uptake (54 ± 8 to 60 ± 7 ml/kg/min) in aerobic PP. Oxygen uptake at the respiratory compensation point (RCP) (46 ± 6 to 50 ± 5 ml/kg/min), with a moderate effect size for both variables, was observed in the EG after IMT. We concluded that IMT provided a significant increase in respiratory muscle strength and resistance, contributing to increased aerobic PP in the EG, which suggests that IMT could be incorporated in handball players' training.

Respiratory muscle strength and aerobic performance of wheelchair basketball players

The respiratory system has been described as a limiting factor in the performance of athletes. Therefore, the objective of this study was to evaluate the relationship between the respiratory muscle strength (RMS) and aerobic performance of wheelchair basketball players (WCBPs). We evaluated 19 male WCBPs who were divided into two groups: trunk control group (TCG) and without trunk control group (WTCG). All participants underwent a pulmonary function test, evaluation of maximal inspiratory (MIP) and expiratory (MEP) pressures, and an aerobic performance test. The MIP of both groups and the MEP values of TCG exceeded the predicted values for age and gender. No differences were observed in the MIP and aerobic performance between the groups although a difference was observed in the MEP values. Positive correlations were observed between MIP/MEP and the aerobic performance for both groups. These results suggested that the overall RMS of this group of WCBPs fell within or above the predicted values. Hence, the study concluded that RMS can positively influence the aerobic performance of WCBP

Interval training based on ventilatory anaerobic threshold increases cardiac vagal modulation and decreases high-sensitivity c-reative protein: randomized clinical trial in coronary artery disease.

BACKGROUND: Autonomic dysfunction and inflammatory activity are involved in the development and progression of coronary artery disease (CAD), and exercise training has been shown to confer a cardiovascular benefit. OBJECTIVE: To evaluate the effects that interval training (IT) based on ventilatory anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as the relationship between both levels, in patients with CAD and/or cardiovascular risk factors (RF). METHOD: Forty-two men (aged 57.88±6.20 years) were divided into two training groups, CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C (n=10). Heart rate and RR intervals in the supine position, cardiopulmonary exercise tests, and hs-CRP levels were measured before and after IT. HRV was analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week IT program of three weekly sessions at training intensities based on the VAT. RESULTS: In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased (p<0.02), while cardiac parasympathetic modulation index increased (p<0.02). In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP, systolic, and diastolic blood pressures decreased (p<0.02). Both control groups showed increase in hs-CRP parameters (p<0.02). There was a strong and significant association between parasympathetic and sympathetic modulations with hs-CRP. CONCLUSION: The IT program based on the VAT promoted a decrease in hs-CRP associated with improvement in cardiac autonomic modulation.

Interval training based on ventilatory anaerobic threshold increases cardiac vagal modulation and decreases high-sensitivity c-reative protein: randomized clinical trial in coronary artery disease

Background: Autonomic dysfunction and inflammatory activity are involved in the development and progression of coronary artery disease (CAD), and exercise training has been shown to confer a cardiovascular benefit. Objective: To evaluate the effects that interval training (IT) based on ventilatory anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as the relationship between both levels, in patients with CAD and/or cardiovascular risk factors (RF). Method: Forty-two men (aged 57.88±6.20 years) were divided into two training groups, CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C (n=10). Heart rate and RR intervals in the supine position, cardiopulmonary exercise tests, and hs-CRP levels were measured before and after IT. HRV was analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week IT program of three weekly sessions at training intensities based on the VAT. Results: In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased (p<0.02), while cardiac parasympathetic modulation index increased (p<0.02). In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP, systolic, and diastolic blood pressures decreased (p<0.02). Both control groups showed increase in hs-CRP parameters (p<0.02). There was a strong and significant association between parasympathetic and sympathetic modulations with hs-CRP. Conclusion: The IT program based on the VAT promoted a decrease in hs-CRP associated with improvement in cardiac autonomic modulation.

Wheelchair rugby improves pulmonary function in people with tetraplegia after 1 year of training.

This study investigated the effects of 1 year of regular wheelchair rugby training on the pulmonary function of subjects with tetraplegia. A total of 15 male subjects with tetraplegia participated in this study and were divided into an experimental group of rugby players (n = 8) and a control group (n = 7) of sedentary tetraplegic subjects. Both groups underwent spirometry, and the experimental group was tested before and after participating of a regular 1-year program of wheelchair rugby training. At the beginning of the training program, all the subjects presented reduced pulmonary function compared with predicted values (p < 0.05) for healthy subjects. There were a significant increase in forced vital capacity (FVC), forced expired volume after 1 second (FEV1), and maximal voluntary ventilation (MVV, p < 0.05) values after 1 year of regular wheelchair rugby training. The regression analysis between total training time and spirometric variables FVC (r = 0.97, p < 0.0001) and MVV (r = 0.58, p = 0.02) revealed that the players with longer training time had higher pulmonary function values. This study showed that regular wheelchair rugby training can improve the pulmonary function of subjects with spinal cord injuries.

Assessment of Subjective Perceived Exertion at the Anaerobic Threshold with the Borg CR-10 Scale.

The purpose of this study was to evaluate the anaerobic threshold (AT) with a graphic visual method for estimating the intensity of ventilatory and metabolic exertion and to determine the ratings of perceived exertion (RPE) on the Borg CR-10 scale during a continuous ramp type exercise test (CT-R). Forty healthy, physically active and sedentary young women (age 23.1 ± 3.52 years) were divided into two groups according to their fitness level: active group (AG) and sedentary group (SG) and were submitted to a CT-R on a cycloergometer with 20 to 25 W/min increments. Shortly before the end of each one-minute period, the subjects were asked to rate dyspnea (RPE-D) and leg fatigue (RPE-L) on the Borg CR-10 scale. After the AT was determined with the graphic visual method, the score that the volunteers gave on the Borg CR10 scale was verified. Data were analyzed using the Mann-Whitney and Spearman correlation tests with the significance level set at 5%. The mean ratings of RPE-L and RPE-D at the AT level were not significantly different between groups (p > 0.05). Significant correlations were found between VO2, heart rate (HR), power output and RPE for both groups. The muscular and respiratory RPE, according to the Borg CR-10 scale, were correlated with the AT, suggesting that scores close to 5, which correspond to a "strong" perception, may be used as parameters for quantifying aerobic exercise intensity for active and sedentary individuals. The similar perception of exercise intensity, which corresponded to the AT of different individuals, makes it possible to prescribe exercise at an intensity equivalent to the AT by means of the RPE. Key pointsInterest in quantitative and systematic determination of the AT is growing, however, qualitative studies measure the AT by perceived exertion, are still unsubstantial.Borg CR-10 scale is a category scale with ratio properties consisting of numbers related to verbal expressions, which allows rate comparison between intensities as well as a determination of intensity levels.Scores close to 5 expressed on the Borg CR-10 scale, which correspond to a "strong" perception, may be used as parameters for quantifying the aerobic exercise intensity of both active and sedentary women.