Inspiratory Muscle Warm-up Research Articles

The Relationship between Inspiratory Muscle Strength and Cycling Performance: Insights from Hypoxia and Inspiratory Muscle Warm-Up.

Hypoxia increases inspiratory muscle work and consequently contributes to a reduction in exercise performance. We evaluate the effects of inspiratory muscle warm-up (IMW) on a 10 km cycling time trial in normoxia (NOR) and hypoxia (HYP). Eight cyclists performed four time trial sessions, two in HYP (FiO2: 0.145) and two in NOR (FiO2: 0.209), of which one was with IMW (set at 40% of maximal inspiratory pressure-MIP) and the other was with the placebo effect (PLA: set at 15% MIP). Time trials were unchanged by IMW (NORIMW: 893.8 ± 31.5 vs. NORPLA: 925.5 ± 51.0 s; HYPIMW: 976.8 ± 34.2 vs. HYPPLA: 1008.3 ± 56.0 s; p > 0.05), while ventilation was higher in HYPIMW (107.7 ± 18.3) than HYPPLA (100.1 ± 18.9 L.min-1; p ≤ 0.05), and SpO2 was lower (HYPIMW: 73 ± 6 vs. HYPPLA: 76 ± 6%; p ≤ 0.05). A post-exercise-induced reduction in inspiratory strength was correlated with exercise elapsed time during IMW sessions (HYPIMW: r = -0.79; p ≤ 0.05; NORIMW: r = -0.70; p ≤ 0.05). IMW did not improve the 10 km time trial performance under normoxia and hypoxia.

Effects of inspiratory muscle warm-up on perceptual, physiological, and performance outcomes during high-intensity exercise in normoxia and hypoxia

Some evidence shows that an inspiratory muscle warm-up (IMW) could enhance exercise performance; however, the mechanistic basis is unclear. PURPOSE: To examine how IMW affects the sensory and affective components of dyspnea, exercise performance, and locomotor muscle oxygenation. METHODS: Thirteen recreationally active individuals (23 ± 5 yr, 5 women) performed a cycling time to exhaustion test (~80-85% VȮ2max) preceded by either IMW (2x30 breaths, 40% maximal inspiratory pressure) or SHAM (2x30 breaths, 15% maximal inspiratory pressure) in normoxic (FIO2 = 0.21) and hypoxic (FIO2 = 0.16) conditions (i.e., 4 trials total). NIRS, dyspnea (i.e., breathing intensity and breathing unpleasantness), and cardiorespiratory parameters were measured throughout. Cardiorespiratory variables were analyzed using the individual isotime method. RESULTS: There were no differences in mean dyspnea responses between IMW and SHAM ( p > 0.05). Mean Δ tissue saturation index (TSI) did not reach statistical significance between IMW and SHAM in normoxia ( p = 0.110) or hypoxia ( p = 0.07). Mean performance was not different in normoxia ( p = 0.636) or hypoxia ( p = 0.512). In normoxia, V̇E ( p = 0.059) and fB ( p = 0.056) approached significance with IMW values greater compared to SHAM in the third isotime. CONCLUSION: Group improvements in dyspnea, performance, and ΔTSI were not seen following IMW. However, the degree of select individual responses suggest this intervention has interindividual applicability that should not be overlooked. No external funding was received for this work. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effects of High-Intensity Inspiratory Muscle Warm-Up on High-Intensity Exercise Performance and Muscle Oxygenation.

An inspiratory muscle warm-up (IMW) improves inspiratory muscle function, but the effects of high-intensity exercise are inconsistent. We aimed to determine the effects of high-intensity IMW on high-intensity exercise performance and muscle oxygenation. Ten healthy men (maximal oxygen uptake [V˙O2max] 52.2 [5.0]mL·kg-1·min-1) performed constant-load exercise to exhaustion on a cycle ergometer at V˙O2max under 2 IMW conditions: a placebo condition (PLA) and a high-intensity IMW condition (HIGH). The inspiratory loads were set at 15% and 80% of maximal inspiratory pressure, respectively. Maximal inspiratory pressure was measured before and after IMW. Oxyhemoglobin was measured in the vastus lateralis by near-infrared spectroscopy during exercise. Rating of perceived exertion (RPE)for a leg was measured after 1 and 2minutes of exercise. Exercise tolerance was significantly higher under HIGH than PLA (228 [49]s vs 218 [49]s, P = .003). Maximal inspiratory pressure was significantly increased by IMW under HIGH (from 125 [20] to 136 [25] cm H2O, P = .031). Oxyhemoglobin was significantly higher under HIGH than PLA at 80% of the total duration of exercise (P = .048). RPE for the leg was significantly lower under HIGH than PLA after 2minutes of exercise (P = .019). Given that oxyhemoglobin is an index of local oxygen supply, the results of this study suggest that high-intensity IMW increases the oxygen supply to active limbs. It may also reflect a reduction in RPE in the leg. In addition, high-intensity IMW may improve exercise performance.

Effects of high-intensity inspiratory muscle warm-up on inspiratory muscle strength and accessory inspiratory muscle activity

This study aimed to determine the effects of work-matched moderate-intensity and high-intensity inspiratory muscle warm-up (IMW) on inspiratory muscle strength and accessory inspiratory muscle activity. Eleven healthy men performed three IMWs at different intensities, namely, placebo, moderate-intensity, and high-intensity, set, respectively, at 15 %, 40 %, and 80 % of maximal inspiratory mouth pressure (MIP). MIP was measured before and after IMW. Electromyography (EMG) was recorded for the sternocleidomastoid muscle (SCM) and intercostal muscles (IC) during IMW. MIP increased significantly in the moderate-intensity condition (104.2 ± 5.1 %, p < 0.05) and high-intensity condition (106.5 ± 6.2 %, p < 0.01) after IMW. The EMG amplitudes of the SCM and IC during IMW were significantly higher in the order of high-intensity, moderate-intensity, and placebo conditions. There was a significant correlation between changes in MIP and EMG amplitude of the SCM (r = 0.60, p < 0.01) and IC (r = 0.47, p < 0.01) during IMW. These findings suggest that high-intensity IMW increases neuromuscular activity in the accessory inspiratory muscles, which may improve inspiratory muscle strength.

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.

What is the Most Important Percentage of Pressure in Inspiratory Muscle Warm-Up Exercises for Children?

It has been observed that device inspiratory muscle warm-up exercises (IMW-D), which has started to take place in general warm-up in recent years, contribute to performance in a positive fashion. In the literature, IMW-Ds are usually performed with 40% of maximum inspiratory pressure (MIP). There is not a single study explaining or determining the best percentage of MIP in both acute and chronic studies on IMW-Ds in the literature. Therefore, in this study, it was aimed to determine the most important pressure percentage to improve respiratory parameters in IMW-Ds. A total of 40 athletes with licenses in a federation between the ages of 12-14 participated in the study. Participants underwent IMW-D with a powerbreathe plus respiratory exercise device at 15%, 30%, 40%, 45%, 50% and 60% of the MIP on different days, and immediately following these exercises were performed with a spirometer, respiratory parameters were measured as (FVC, FEV1, PEF). Kruskal Wallis H test was used in order to determine the difference between measurements. As a result of statistical analysis, it was found that while there was significant difference in PEF values between 15% and 40%, 45% of MIP; and the highest improvement was 45%, 50% and 60% of MIP in FVC, FEV1 and PEF values. It can be suggested that sedentary people and athletes who want to improve their respiratory parameters can also train with 45%, 50% and 60% of MIP without depending on 40% of the MIP applied only as given in the literature for a higher improvement in their IMW-D.

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.

ACUTE EFFECT OF INSPIRATORY MUSCLE WARM UP PROTOCOL ON DYNAMIC AND STATIC BALANCE PERFORMANCE

The aim of this study is to examine the acute effect of inspiratory muscle warm-up protocol on dynamic and static balance performance. For this purpose, 17 sedentary individuals participated whose ages were between 20-26 years old. On different days, right static, left static, right dynamic and left dynamic tests were applied to the subjects randomly after control, placebo and experimental protocol. PowerBreathe brand inspiratory training device was used for inspiratory warming and Biodex Balance SD isokinetic balance test mechanism was used for measurement. The data obtained as a result of the test were analyzed by using the SPSS package program version 22.0. The data obtained were analyzed separately for General balance, Anterior-Posterior (A-P) balance and Medial-Lateral (M-L) balance groups. According to the result obtained, while the inspiratory warming protocol created a significant positive effect in some balance groups, it did not create a significant effect in some balance groups. Therefore, it can be said that the inspiratory warming protocol affects some balance parameters but this effect is not a level that can directly benefit the performance.&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/edu_01/0938/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

Reproducibility of Maximum Respiratory Pressure Assessment: A Systematic Review and Meta-analysis

Accurate assessment of maximum respiratory pressure is vital when tracking disease progression and devising treatment strategies. Previous studies indicate a learning effect when undertaking maximum respiratory pressure measurements. The extent of this learning effect and methodologies undertaken to mitigate this learning effect have not been investigated systematically. What is the magnitude of improvements in maximum respiratory pressure in response to respiratory muscle warm-up protocols and repeated measures of maximum respiratory pressure in healthy individuals and clinical populations? A comprehensive search of electronic databases was undertaken during August 2021 for studies examining the intrarater reliability of maximum inspiratory or expiratory pressure, or both, studies developing a protocol or an intervention to obtain maximum values, and studies analyzing the reliability of repeated maneuvers in a single testing session in healthy individuals and clinical populations. Included articles were analyzed critically using two appraisal tools. Standardized mean differences with 95%CIs were calculated and corrected for the sample size as a measure of the magnitude of change in maximum respiratory pressure outcomes. Of the 1,969 articles retrieved, 32 were included in the meta-analysis. Eighteen studies included healthy individuals and 14 studies included individuals with chronic medical conditions. The overall effect of inspiratory muscle warm-up protocols was higher (effects size [ES], 0.40; 95%CI, 0.17-0.63) in comparison with single testing session studies (ES, 0.20; 95%CI, 0.05-0.35) and studies performing repeated testing sessions of maximum respiratory pressure (ES, 0.14; 95%CI, 0.07-022). Inspiratory muscles warm-up procedures induce higher increases in maximum inspiratory pressure in comparison with single and repeated testing sessions of maximum respiratory pressure in healthy individuals. Warm-up protocols are more effective to obtain the maximum performance of inspiratory muscles in one testing session in comparison with other methods. PROSPERO; No.: CRD42022304591; URL: https://www.crd.york.ac.uk/prospero/.

The Effect of Inspiratory Muscle Warm-Up on Incremental Exercise Test Performance in Hypoxic Environment

The Effect of Inspiratory Muscle Warm-Up on Incremental Exercise Test Performance in Hypoxic Environment

THE EFFECT OF INSPIRATORY MUSCLE WARM-UP PROTOCOL ON ACCELERATION AND MAXIMAL SPEED IN 12-14 YEARS OLD CHILDREN

The aim of this study is to investigate the effect of the inspiratory muscle warm-up protocol on acceleration and maximal speed in children aged 12-14. Thirty sedentary boys (age: 12.63 ± 0.89 years) participated in the study. Participants were randomly included in 4 different trials (T1, T2, T3, T4). Acceleration (10m, 20m) and maximal speed tests (30m, 50m) were randomly tested at 10 minutes intervals in each trial. Acceleration and speed tests were performed without any warm-up in T1 trial, with general warm-up in T2 trial, placebo inspiratory muscle warm-up in T3 trial, and inspiratory muscle warm-up in T4 trial. As a result of the statistical analysis, it was seen that general warm-up (T2) and inspiratory muscle warm-up (T4) increased performance significantly compared to control (T1) and placebo (T3) trials in all acceleration and speed tests (p &lt;0.05). In conclusion, it can be said that the inspiratory muscle warm-up protocol has positive effects on acceleration and maximal speed performances, similar to general warm-up.&#x0D; &#x0D; &lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/edu_01/0799/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

INFLUENCE OF INSPIRATORY MUSCLE WARM-UP EXERCISE ON FIELD HOCKEY DRAG-FLICK AND SHOOTING PERFORMANCE

The aim of this study is to examine the effect of inspiratory muscle exercise on drag-flick and shooting performance in hockey. For this purpose, 30 individuals engaged in hockey sports participated in the study as an experimental group. The subjects were applied three inspiratory muscle warm-up exercises (maximal inspiratory pressure, MIP): at 5% intensity (placebo) and 40% intensity (RWU), with 30 breaths x 2 sets and 1 minute rest between sets, first without warming up. After each test, 20 shots drag-flick and 20 shots were performed at the hockey goal, whose scoring was prepared before. The data obtained were analyzed in SPSS 22.0 program. After testing for normality and homogeneity, one-way analysis of variance and LSD correction were performed for repeated measurements. According to the one-way analysis of variance test in repeated measurements; in the drag-flick performance test, a significant difference in favor of the RWU application was observed between the RWU application and placebo and no warming applications (p &lt;0.05). In the shooting performance test, there was a significant difference between RWU application and placebo and no warm-up applications in favor of RWU application (p &lt;0.05). In the drag-flick performance test, when the change of the fatigue scores of the subjects between the applications was examined; there was a significant difference in favor of RWU application (p &lt;0.05). Fatigue was found to be less in RWU application. When the change of fatigue scores between applications in the shooting performance test was examined; there was a significant difference between RWU application and placebo and no warming applications in favor of RWU application (p &lt;0.05). Fatigue was found to be less in RWU application. As a result, it can be said that inspiratory muscle exercise has a positive effect on drag-flick and shooting performance in hockey.&#x0D; &#x0D; &lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/edu_01/0776/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

The Effect of Inspiratory Muscle Warm-Up on VO2 Kinetics during Submaximal Rowing.

The aim of the study was to investigate the effect of an inspiratory muscle warm-up on the VO2 kinetics during submaximal intensity ergometer rowing. Ten competitive male rowers (age 23.1 ± 3.8 years; height 188.1 ± 6.3 cm; body mass 85.6 ± 6.6 kg) took part in this investigation. A submaximal constant intensity (90% PVO2max) rowing test to volitional exhaustion was carried out twice with the standard rowing warm-up (Test 1) and with the standard rowing warm-up with additional specific inspiratory muscle warm-up of two sets of 30 repetitions at 40% maximal inspiratory pressure (Test 2). We found a significant correlation between time constant (τ1) and the VO2 value at 400 s in Test 1 (r = 0.78; p < 0.05); however, no correlation was found between those parameters in Test 2. In addition, we found a positive association between VO2max from the incremental rowing test and τ1 from Test 1 (r = 0.71; p < 0.05), whereas VO2 did not correlate with τ1 from Test 2. Adding inspiratory muscle warm-up of 40% maximal inspiratory pressure to regular rowing warm-up had no significant effect on oxygen consumption kinetics during submaximal rowing tests.

ACUTE EFFECT OF INSPIRATORY MUSCLE WARM-UP PROTOCOL ON KNEE FLEXION-EXTENSION ISOKINETIC STRENGTH

In this study, it was planned to investigate the acute effect of inspiratory muscle warm-up protocol on knee flexion-extension isokinetic strength. In our study, control and two different experimental applications were performed on sedentary individuals (n: 15, age: 22.25 ± 1.49 years). In the control application, the subjects participated in the 60os-1 180os-1 and 240os-1 knee flexion-extension isokinetic test, respectively, without general warm-up. Isokinetic tests performed after general warm-up in one of the experimental trials. In the other experimental trial, in addition to general warming, the same isokinetic tests were performed after performing 30 breaths of respiratory muscle twice at 40% maximal inspiratory pressure intensity. One-way analysis of variance and LSD tests were performed for repeated measurements to determine the difference between trials. There were significant differences in 60o PT H / Q Ratio, 60o WH / Q Ratio, 60o PTEx, 60o WEx, 60o PTFlx, 60o FIFlx and 60o WFlx 180o PT H / Q Ratio (%), 180o PTEx (nm), 180o APEx (watts), 180o PTFlx (nm), 180o FIFlx (nm), 180o WFlx (nm / repeat) 240o PTEx (nm), 240o WEx (nm / repeat), 240o PTFlx (nm), 240o FIFlx (nm) and 240o WFlx (nm / repeat) parameters in favor of experimental applications (p 0.05). As a result, it can be said that inspiratory muscle warm-up exercise lowers the fatigue index and therefore increases the peak torque, average power and total workforce, and it affects the knee flexion-exudate isokinetic strength acutely. Article visualizations:

Inspiratory Muscle Warm-up Improves 3,200-m Running Performance in Distance Runners.

Barnes, KR and Ludge, AR. Inspiratory muscle warm-up improves 3,200-m running performance in distance runners. J Strength Cond Res 35(6): 1739-1747, 2021-This study examined the effects of an inspiratory muscle exercise as part of a warm-up (IMW) using a resisted breathing trainer on running performance. In a randomized crossover design, 17 trained distance runners completed two 3,200-m performance trials on separate days, preceded by 2 different warm-up procedures: IMW or sham IMW (CON). In each condition, subjects performed 30 breaths against either 50% of each athlete's peak strength (IMW) or 30 slow protracted breaths against negligible resistance (CON). Perceived race readiness and inspiratory muscle strength, flow, power, and volume were measured before and after each warm-up. Heart rate (HR), rating of perceived exertion (RPE) and dyspnea (RPD), and expired gases were collected during each trial. A 3,200-m run performance was 2.8% ± 1.5% (20.4-second) faster after IMW (effect size [ES] = 0.37, p = 0.02). After each warm-up condition, there was as small effect on peak inspiratory strength (6.6 ± 4.8%, ES = 0.22, p = 0.02), flow (5.2 ± 4.4%, ES = 0.20, p = 0.03), power (17.6 ± 16.7%, ES = 0.22, p = 0.04), and volume (6.7 ± 6.3%, ES = 0.24, p = 0.01) after IMW compared with CON. There were no differences in HR, minute volume, peak V̇o2, or V̇o2 at each 800-m interval between conditions (ES ≤ 0.13, p > 0.17). There were small differences in RPE at 800 m and 1,600 m (ES = 0.32, p = 0.17; ES = 0.21, p = 0.38, respectively), but no difference at the last 1,600 m (p = 1.0). There was a moderate positive effect on RPD (ES = 0.81, p < 0.001) and race readiness (ES = 0.76, p < 0.01) after IMW. Overall, the data suggest that IMW improves 3,200-m performance because of enhancements in inspiratory muscle function characteristics and reduction in dyspnea.

Effects of inspiratory muscle warm-up on locomotor muscle oxygenation in elite speed skaters during 3000m time trials.

It has been shown that an inspiratory muscle warm-up (IMW) could enhance performance. IMW may also improve the near-infrared spectroscopy (NIRS)-derived tissue oxygen saturation index (TSI) during cycling. However, there exists contradictory data about the effect of this conditioning strategy on performance and muscle oxygenation. We examined the effect of IMW on speed skating performance and studied the underpinning physiological mechanisms related to muscle oxygenation. In a crossover, randomized, single-blind study, eight elite speed skaters performed 3000m on-ice time trials, preceded by either IMW (2 × 30 breaths, 40% maximal inspiratory pressure) or SHAM (2 × 30 breaths, 15% maximal inspiratory pressure). Changes in TSI, oxyhemoglobin-oxymyoglobin ([O2HbMb]), deoxyhemoglobin-deoxymyoglobin ([HHbMb]), total hemoglobin-myoglobin ([THbMb]) and HHbMbdiff ([O2HbMb]-[HHbMb]) in the right vastus lateralis muscle were monitored by NIRS. All variables were compared at different time points of the race simulation with repeated-measures analysis of variance. Differences between IMW and SHAM were also analyzed using Cohen's effect size (ES) ± 90% confidence limits, and magnitude-based inferences. Compared with SHAM, IMW had no clear impact on skating time (IMW 262.88 ± 17.62s vs. SHAM 264.05 ± 21.12s, effect size (ES) 0.05; 90% confidence limits, - 0.22, 0.32, p = 0.7366), TSI, HbMbdiff, [THbMb], [O2HbMb] and perceptual responses. IMW did not modify skating time during a 3000m time trial in speed skaters, in the conditions of our study. The unchanged [THbMb] and TSI demonstrate that the mechanisms by which IMW could possibly exert an effect on performance were unaffected by this intervention.

Influence of inspiratory muscle warm-up on aerobic performance during incremental exercise

Influence of inspiratory muscle warm-up on aerobic performance during incremental exercise

Combining Chronic Ischemic Preconditioning and Inspiratory Muscle Warm-Up to Enhance On-Ice Time-Trial Performance in Elite Speed Skaters.

Elite athletes in varied sports typically combine ergogenic strategies in the hope of enhancing physiological responses and competitive performance, but the scientific evidence for such practices is very scarce. The peculiar characteristics of speed skating contribute to impede blood flow and exacerbate deoxygenation in the lower limbs (especially the right leg). We investigated whether combining preconditioning strategies could modify muscular oxygenation and improve performance in that sport. Using a randomized, single-blind, placebo-controlled, crossover design, seven male elite long-track speed skaters performed on-ice 600-m time trials, preceded by either a combination of preconditioning strategies (COMBO) or a placebo condition (SHAM). COMBO involved performing remote ischemic preconditioning (RIPC) of the upper limbs (3 × 5-min compression at 180 mmHg and 5-min reperfusion) over 3 days (including an acute treatment before trials), with the addition of an inspiratory muscle warm-up [IMW: 2 × 30 inspirations at 40% maximal inspiratory pressure (MIP)] on the day of testing. SHAM followed the same protocol with lower intensities (10 mmHg for RIPC and 15% MIP). Changes in tissue saturation index (TSI), oxyhemoglobin–oxymyoglobin ([O2HbMb]), deoxyhemoglobin–deoxymyoglobin ([HHbMb]), and total hemoglobin–myoglobin ([THbMb]) in the right vastus lateralis muscle were monitored by near-infrared spectroscopy (NIRS). Differences between COMBO and SHAM were analyzed using Cohen’s effect size (ES) and magnitude-based inferences. Compared with SHAM, COMBO had no worthwhile effect on performance time while mean Δ[HHbMb] (2.7%, ES 0.48; -0.07, 1.03) and peak Δ[HHbMb] (1.8%, ES 0.23; -0.10, 0.57) were respectively likely and possibly higher in the last section of the race. These results indicate that combining ischemic preconditioning and IMW has no practical ergogenic impact on 600-m speed-skating performance in elite skaters. The low-sitting position in this sport might render difficult enhancing these physiological responses.

Assessment of Maximum Dynamic Inspiratory Pressure.

Inspiratory muscle strength has been considered an important marker of ventilatory capacity and a predictor of global performance. A new tool has become available for dynamically evaluating the maximum inspiratory pressure (the S-Index). However, the proper assessment of this parameter needs to be determined. Thus, the aim of the present study was to investigate the number of inspiratory maneuvers necessary to reach a maximum and reliable S-Index and the influence of inspiratory muscle warm-up on this assessment. We performed a retrospective study from the database of 432 healthy subjects who underwent S-Index tests and inspiratory muscle warm-up or sham. The effect of repeated maneuvers on the S-Index and the impact of inspiratory muscle warm-up were analyzed by using the intraclass correlation coefficient and unpaired t test. We analyzed 81 subjects, (55% men), mean ± SD age 38.1 ± 9.6 y, 43 subjects in the inspiratory muscle warm-up group. Maximum and reliable S-Indexes were reached at the eighth maneuver in both groups preceding inspiratory muscle warm-up or sham, 102 cm H2O (95% CI 95-109 cm H2O); intraclass correlation coefficient 0.96; P < .001. Only the inspiratory muscle warm-up group presented a significant increase in the S-Index after warm-up, 13.5 cm H2O (95% CI 10-17), P < .001. Eight maneuvers were necessary to reach maximum and reliable values of the S-Index preceding inspiratory muscle warm-up or sham. Moreover, inspiratory muscle warm-up preceding S-Index assessment improved inspiratory muscle performance.

Whole-body active warm-up and inspiratory muscle warm-up do not improve running performance when carrying thoracic loads.

Whole-body active warm-ups (AWU) and inspiratory muscle warm-up (IMW) prior to exercise improves performance on some endurance exercise tasks. This study investigated the effects of AWU with and without IMW upon 2.4-km running time-trial performance while carrying a 25-kg backpack, a common task and backpack load in physically demanding occupations. Participants (n = 9) performed five 2.4-km running time-trials with a 25-kg thoracic load preceded in random order by (i) IMW comprising 2 × 30 inspiratory efforts against a pressure-threshold load of 40% maximal inspiratory pressure (PImax), (ii) 10-min unloaded running (AWU) at lactate turnpoint (10.33 ± 1.58 km·h-1), (iii) placebo IMW (PLA) comprising 5-min breathing using a sham device, (iv) AWU+IMW, and (v) AWU+PLA. Pooled baseline PImax was similar between trials and increased by 7% and 6% following IMW and AWU+IMW (P < 0.05). Relative to baseline, pooled PImax was reduced by 9% after the time-trial, which was not different between trials (P > 0.05). Time-trial performance was not different between any trials. Whole-body AWU and IMW performed alone or combination have no ergogenic effect upon high-intensity, short-duration performance when carrying a 25-kg load in a backpack.