Maximal Aerobic Test Research Articles

The influence of muscle strength and aerobic fitness on functional recovery in elite female soccer players.

We examined the influence of muscle strength and aerobic fitness on wellbeing and muscle function recovery in female soccer players. Sixteen players from the English Women's Super League (age: 26±4 yrs; height, 1.70±0.07 m; mass, 67.9±6.4 kg) completed an isometric mid-thigh pull test (IMTP) and maximal aerobic speed test (MAST). Using a median split, players were divided by strength into high (H-IMTP) and low (L-IMPT) groups and by fitness into high (H-MAST) and low (L-MAST) groups. Countermovement jump height (CMJ), Reactive Strength Index (RSI) and wellbeing were measured 2 days prematch, then 3 subsequent days post-match (M+1, M+2, M+3). In H-IMTP, CMJ, RSI and wellbeing were higher at M+1-M+3 (P<0.05). At M+3, CMJ in H-IMTP was 30.3±3.5 cm vs. 26.2±3.4 in L-IMTP. CMJ and wellbeing were unaffected by fitness, but RSI was lower at M+1-M+3 in the L-IMTP group (P<0.05). In conclusion, isometrically stronger but not aerobically fitter female soccer players recover quicker after matches.

Re-evaluating the Need for Routine Maximal Aerobic Capacity Testing within Fighter Pilots.

INTRODUCTION: There is a current belief in aviation suggesting that aerobic training may reduce G-tolerance due to potential negative impacts on arterial pressure response. Studies indicate that increasing maximal aerobic capacity (<mml:math id="ie1" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂ max) through aerobic training does not hinder G-tolerance. Moreover, sustained centrifuge training programs revealed no instances where excessive aerobic exercise compromised a trainee's ability to complete target profiles. The purpose of this review article is to examine the current research in the hope of establishing the need for routine <mml:math id="ie2" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max testing in air force pilot protocols.METHODS: A systematic search of electronic databases including Google Scholar, PubMed, the Aerospace Medical Association, and Military Medicine was conducted. Keywords related to "human performance," "Air Force fighter pilots," "aerobic function," and "maximal aerobic capacity" were used in various combinations. Articles addressing exercise physiology, G-tolerance, physical training, and fighter pilot maneuvers related to human performance were considered. No primary data collection involving human subjects was conducted; therefore, ethical approval was not required.RESULTS: The <mml:math id="ie3" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max test provides essential information regarding a pilot's ability to handle increased Gz-load. It assists in predicting G-induced loss of consciousness by assessing anti-G straining maneuver performance and heart rate variables during increased G-load.DISCUSSION: <mml:math id="ie4" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max testing guides tailored exercise plans, optimizes cardiovascular health, and disproves the notion that aerobic training hampers G-tolerance. Its inclusion in air force protocols could boost readiness, reduce health risks, and refine training for fighter pilots' safety and performance. This evidence-backed approach supports integrating <mml:math id="ie5" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max testing for insights into fitness, risks, and tailored exercise.Zeigler Z, Acevedo AM. Re-evaluating the need for routine maximal aerobic capacity testing within fighter pilots. Aerosp Med Hum Perform. 2024; 95(5):273-277.

Performance Evaluation of a New Sport Watch in Sleep Tracking: A Comparison against Overnight Polysomnography in Young Adults.

Introduction: This study aimed to validate the ability of a prototype sport watch (Polar Electro Oy, FI) to recognize wake and sleep states in two trials with and without an interval training session (IT) 6 h prior to bedtime. Methods: Thirty-six participants completed this study. Participants performed a maximal aerobic test and three polysomnography (PSG) assessments. The first night served as a device familiarization night and to screen for sleep apnea. The second and third in-home PSG assessments were counterbalanced with/without IT. Accuracy and agreement in detecting sleep stages were calculated between PSG and the prototype. Results: Accuracy for the different sleep stages (REM, N1 and N2, N3, and awake) as a true positive for the nights without exercise was 84 ± 5%, 64 ± 6%, 81 ± 6%, and 91 ± 6%, respectively, and for the nights with exercise was 83 ± 7%, 63 ± 8%, 80 ± 7%, and 92 ± 6%, respectively. The agreement for the sleep night without exercise was 60.1 ± 8.1%, k = 0.39 ± 0.1, and with exercise was 59.2 ± 9.8%, k = 0.36 ± 0.1. No significant differences were observed between nights or between the sexes. Conclusion: The prototype showed better or similar accuracy and agreement to wrist-worn consumer products on the market for the detection of sleep stages with healthy adults. However, further investigations will need to be conducted with other populations.

Sense of time is slower following exhaustive cycling exercise.

Subjective perception of time is altered during vigorous exercise. This could be due in part to the fatigue associated with physical activity at high intensities. The aim of this study was to determine the effect of fatigue, specifically, on subjective time perception. Twenty-six healthy, untrained subjects (17 men/9 women; age = 26.0 ± 4.3years; peak = 38.13 ± 5.62mL/kg/min) completed a maximal aerobic exercise test on a cycle ergometer. Time perception was assessed before (PRE) and after (POST) the exercise test using a time production task wherein subjects started a stopwatch and stopped it once they believed a designated time period had passed. This time produced with the stopwatch was the estimate of the target time that was compared to the target time interval. Relative error of the timing task was significantly higher for POST (0.112 ± 0.260) than for PRE (0.028 ± 0.173), p = .032, η2 = .178. Subjects produced ~ 8.4% more time than the target intervals when fatigued, which is indicative of a slower sense of time perception. A shift in attentional focus from timing to the sensations associated with fatigue is a possible factor to explain this result. Future studies which investigate the effects of exercise on time perception should consider the impact of fatigue experienced during exercise.

Non-traditional HIIT-style ROTC training elicits positive bone quality and performance adaptations

ABSTRACT Military personnel experience elevated bone injury incidence, partly due to arduous and repetitive training. Non-traditional High-Intensity Interval Training-style (HIIT) may benefit pre-enlisted Reserve Officer Training Corps (ROTC) cadet’s musculoskeletal health and performance prior to military service. This study investigated 16 ROTC (n = 12 males; n = 4 females) and 15 physically active sex-, age-, and body mass-matched Controls’ musculoskeletal health and performance from November to April. Total body, lumbar spine, and dual- hip dual-energy X-ray absorptiometry scans and 4%, 38%, 66% tibial peripheral quantitative computed tomography scans, blood draws (serum sclerostin and parathyroid hormone), and maximal muscle strength and aerobic capacity testing were completed. From November to April, ROTC improved bone density (DXA) of the dominant total hip and greater trochanter and non-dominant greater trochanter and 38% and 66% tibial total volumetric and cortical bone density (pQCT) similarly or more than Controls (all p ≤ 0.049). From November to April, ROTC also improved bench and leg press, and peak aerobic capacity (all p ≤ 0.013). From November to January, serum sclerostin increased (p ≤ 0.007) and remained elevated through April, while parathyroid hormone was unchanged. HIIT-style training induced positive musculoskeletal adaptations, suggesting it may be an excellent pre-service training modality for this injury prone group.

Biomechanical adaptations during exhaustive runs at 90 to 120% of peak aerobic speed

The aim of this study was to examine how running biomechanics (spatiotemporal and kinetic variables) adapt with exhaustion during treadmill runs at 90, 100, 110, and 120% of the peak aerobic speed (PS) of a maximal incremental aerobic test. Thirteen male runners performed a maximal incremental aerobic test on an instrumented treadmill to determine their PS. Biomechanical variables were evaluated at the start, mid, and end of each run until volitional exhaustion. The change of running biomechanics with fatigue was similar among the four tested speeds. Duty factor and contact and propulsion times increased with exhaustion (P ≤ 0.004; F ≥ 10.32) while flight time decreased (P = 0.02; F = 6.67) and stride frequency stayed unchanged (P = 0.97; F = 0.00). A decrease in vertical and propulsive peak forces were obtained with exhaustion (P ≤ 0.002; F ≥ 11.52). There was no change in the impact peak with exhaustion (P = 0.41; F = 1.05). For runners showing impact peaks, the number of impact peaks increased (P ≤ 0.04; {upchi }^{2} ≥ 6.40) together with the vertical loading rate (P = 0.005; F = 9.61). No changes in total, external, and internal positive mechanical work was reported with exhaustion (P ≥ 0.12; F ≤ 2.32). Results suggest a tendency towards a “smoother” vertical and horizontal running pattern with exhaustion. A smoother running pattern refers to the development of protective adjustments, leading to a reduction of the load applied to the musculoskeletal system at each running step. This transition seemed continuous between the start and end of the running trials and could be adopted by the runners to decrease the muscle force level during the propulsion phase. Despite these changes with exhaustion, there were no changes in either gesture speed (no alteration of stride frequency) or positive mechanical work, advocating that runners unconsciously organize themselves to maintain a constant whole-body mechanical work output.

Comparison of Acute Arterial Responses Following a Rescue Simulation and Maximal Exercise in Professional Firefighters

Cardiovascular events are the leading cause of on-duty deaths among firefighters. Screening firefighters for risk of sudden cardiac event is a critical element of a comprehensive medical program. Although intense physical exertion has been shown to trigger sudden cardiac events in the general population, it is unclear how hemodynamic responses following clinical exercise testing compare to that of performing firefighting tasks in personal protective equipment. Therefore, the purpose of this study was to compare hemodynamic responses following rescue simulation (RS) and maximal exercise in firefighters. This was a cross-over repeated measures study. Thirty-eight professional firefighters (31.8 ± 5.2 yr; VO2peak: 57.9 mL/kg/min) completed a maximal aerobic exercise test (MAET) and an RS. Pulse wave velocity (PWV), pulse pressure (PP), and brachial and central mean arterial pressure (MAP) were measured before and 5 and 15 min post-exercise. The findings indicated that femoral PWV decreased after MAET and RS at both time points (p < 0.005). No significant differences were found in aortic and carotid PWV over time or between conditions (p ≥ 0.05). Significant increases in brachial and central PP and MAP were noted 5 min post-MAET and RS (p = 0.004). In conclusion, the present study demonstrated that peripheral arterial stiffness (AS) decreased in firefighters following both conditions, with no differences in central AS. Our findings provide valuable information on hemodynamic responses similar between RS and MAET, and are important for controlling CVD risk and the AS response.

Green and Pleasant Lands: The Affective and Cerebral Hemodynamic Effects of Presence in Virtual Environments During Exercise.

Pleasant exercise experiences increase the likelihood of exercise adherence, and innovative strategies to promote consistently pleasant exercise experiences are needed. In this study we compared a novel nature-based virtual reality environment, a nature-based 360° video, and a control condition to test the hypothesis that greater presence in virtual space would promote positive affective experiences during exercise. Moreover, we assessed prefrontal cerebral hemodynamics using near infrared spectroscopy to explore possible neural underpinnings of dissociative strategies during exercise. Twelve participants (M = 26.2, SD = 7.7years; M BMI = 25.5, SD = 5.2kg/m2) completed a maximal aerobic test and three exercise conditions (Control, Virtual Reality [VR], and 360° video). The two experimental conditions differed in terms of the participants' sense of presence (VR eliciting greatest presence), and all conditions utilized similar exercise intensity. The VR condition setting was a virtual mountain forest trail, and the 360° video was of a forest road. The 360° video was perceived as the most distracting (p = .023, d = 1.07), pleasant (p = .007, d = .75), and enjoyable (p = .029; d = .82) condition. ΔHbDiff data indicated that the control condition caused the greatest prefrontal brain activation (p = .008, d = .84). Presence was not a salient factor in distracting participants from bodily sensations during exercise, but immersion in a stimulus was. These results provide support for using head-mounted displays during exercise as a strategy to increase pleasure, with practical implications for practitioners, researchers, and individuals.

Effect of facemask use on cognitive function during a maximal running aerobic fitness test.

Background: The aim of the present randomized, crossover study was to determine the physiological and cognitive function responses while wearing a facemask during a maximal running aerobic fitness test. Methods: Fourteen healthy, nonsmoking physical education students (age = 17.5 years, height = 1.72 m, body mass = 70.4 kg) volunteered to participate in this study. They carried out a 20 m multistage fitness test (MSFT) while wearing or not a cloth facemask on two separate occasions performed in random order. The “Rating of Perceived Exertion” (RPE) and the d2 test for visual attention were administered and assessed before and immediately after the MSFT for both conditions (with or without a facemask). Results: When wearing the facemask, the participants exhibited lower maximal aerobic speed (p = 0.039), VO2max (p = 0.039), distance covered during the MSFT (p = 0.057), and concentration performance (p < 0.001), when compared with the control situation (without facemask). Moreover, they made more errors compared with the control condition (p = 0.021). The use of a cloth facemask during maximal endurance running tests (such as the MSFT) reduced VO2max, and measures of cognitive performance as assessed by the test of focused visual attention (the d2 test). This data suggests avoiding using a cloth facemask during maximal aerobic fitness tests, and before any tasks that require a high level of visual attention.

Angular Kinematics and Critical Power of Younger and Older Cyclists during the 3-Min All-Out Test

This study aimed to determine differences in angular kinematics and critical power between younger and older cyclists during the 3-min all-out test. Younger (n = 15, 21.8 ± 2.4y) and older (n = 15, 53.3 ± 6.6 y) Category 1 or 2 riders completed maximal aerobic testing and a 3-min all-out test on separate days using their own bicycle on a cycle ergometer. Eight retroreflective markers determined right side sagittal plane angular kinematics during the 3-min all-out test. Younger cyclists displayed higher VO2max, VO2 @ VEbp, HRmax, Power @ VO2max and Critical Power (p &lt; 0.05) than older cyclists. Cadence decreased over time for the combined group (time 1 (T1) = 87.3 ± 4.5 rpm, time 2 (T2) = 83.7 ± 4.6 rpm, and time 3 (T3) = 83.6 ± 5.0 rpm) where T1 was significantly higher than T2 and T3 (p &lt; 0.001), but there were no differences between age groups. Ankle (T1 &gt; T2 &gt; T3, p &lt; 0.026) and foot ranges of motion (T1, T2 &gt; T3, p &lt; 0.01) decreased over time for both age groups. Additionally, younger cyclists had larger ankle and foot ranges of motion (ROM) compared to older cyclists (p = 0.036 and p = 0.032, respectively). Age related differences in physiological measures occurred as expected, although the skill level of the cyclists may explain their similar cadence. Smaller ankle and foot ROM may be strategies to assist force and power generation, particularly in older cyclists as they attempt to overcome aging related physiological declines. With smaller ROM, older cyclists may aim to strengthen ankle musculature and deemphasize high cadence to maintain force generation and critical power.

Changes in acceleration load as measured by inertial measurement units manifest in the upper body after an extended running task

ABSTRACT The purpose of this study was to investigate the behaviour of physiological load measures as well as ground reaction forces (GRF) and acceleration load during a prolonged running task that simulated the running demands of an intermittent team sport. Nineteen males completed a maximal aerobic fitness test and an extended running protocol across two sessions. Participants wore a portable metabolic system, and four inertial measurement units (IMU), one on each foot, the lower back and upper back. GRF were measured via an instrumented treadmill. Change in metabolic, IMU and GRF variables across five blocks during the running protocol were assessed using a one-way repeated measures ANOVA. The running protocol elicited large increases in heart rate and oxygen consumption over time. No statistically significant changes in any peak impact accelerations were observed. Resultant acceleration area under the curve (AUC) increased at the lower and upper back locations but was unchanged at the foot. GRF active peak but not impact peak increased during the prolonged run. The results of this study indicate that the effect of an extended running task on IMU measures of external mechanical load is manifested in the upper body, and is effectively measured by AUC.

Influence of the COVID-19 pandemic on changes in aerobic fitness and injury incidence in elite male soccer players.

The SARS-CoV-2 agent initiated a global pandemic. The initial response to the pandemic was severe disruption to the public and private sector including sports. The resultant was that soccer clubs had to prescribe that the players trained in isolation for a prolonged period of time in an attempt to maintain fitness. The aim of the present study was to evaluate the impact of a 10-week period of training in isolation on aerobic fitness, body composition and injury incidence on the return to preseason team-training in a group of elite, male soccer players. Twenty-two professional soccer players (age: 25.2±4.4 years) who played for an English Championship first team participated in this study. A weekly training program was sent to each player at the start of each week. Prior to the start of the isolated training period, all players underwent a maximal aerobic speed test (MAS), and Body Mass Index data (BMI) were obtained. These measurements were repeated on the return to team training. There was a significant (P<0.05) increase in MAS pre-post isolated training (pre: 4.71±0.15 vs. post: 4.92±0.17 m/s), no change in BMI (pre: 24.3±1.3 vs. post: 24.1±1.1 kg/m2) and a low non-contact, soft-tissue injury incidence on the return to team training. The evidence from this study suggests that a more prolonged preseason schedule can enhance aerobic conditioning and mitigate the injury risk on the return to competitive match-play in elite soccer players.

Enalapril associated with combined training is more effective in reducing SBP and improve baroreflex sensitivity than drug therapies alone in hypertensive rats

High blood pressure is the leading risk factor to development of cardiovascular disease worldwide. Diuretic and angiotensin‐converting enzyme blockers treatment is widely used for its efficiency in reducing blood pressure (BP). Combined physical training (aerobic + resistance) is recommended for hypertensive patients; however, it is not yet clear whether the combination of antihypertensive treatment with this training modality results in additional benefits. Therefore, the aim of this study was to compare the effects of combined training with different drug treatments on systolic BP (SBP) and baroreflex sensitivity (BRS) of spontaneously hypertensive rats (SHR). Twenty‐eight males SHR rats were divided into four groups (n=7/group): HS (sedentary hydrochlorothiazide), HT (trained hydrochlorothiazide), ES (sedentary enalapril) and ET (trained enalapril). Drugs were administered in drinking water (enalapril 3 mg/kg/day and hydrochlorothiazide 30 mg/kg/day). All groups underwent exercise testing before and after 2 months. The trained groups performed combined training 3 times a week, being aerobic and resistance at same session, moderate intensity. The SBP was analyzed by caudal plethysmography before starting the drugs and 24h after the last training session. BRS was analyzed by response to phenylephrine and sodium nitroprusside. Both trained groups increased maximal aerobic exercise test (p&lt;0.0001) and resistance exercise test (HT vs. HS, p=0.02; ET vs. ES, p&lt;0.0001) versus the sedentary groups at the end of the protocol. There was no difference in the initial SBP between the groups (HS 176 ± 4.3, HT 175 ± 3, ES 173 ± 1.4 and ET 183 ± 3 mmHg). There were reductions in SBP in the HT (161 ± 1.3 mmHg), ES (159 ± 4.4 mmHg) and ET groups (147 ± 3.3 mmHg) at the end of the protocol. In addition, the trained group associated with enalapril treatment further reduced SBP when compared to the trained hydrochlorothiazide group (ET vs. HT, p = 0.02). Regarding BRS, there was no difference in tachycardic response between groups; however, ET group (‐2.8 ± 0.5 bpm/mmHg) showed increased bradycardic responses comparing with ES group (‐1.8 ± 0.1 bpm/mmHg). Therefore, the data support that the association of combined exercise training with enalapril treatment and is more effective in reducing SBP and improving BRS than the combination with hydrochlorothiazide treatment. It is noteworthy that the training proposed in this study was performed only three times a week, getting closer to clinical recommendations, and being enough for induce additional benefits to classical drug therapies in functional capacity and blood pressure control in an experimental model of hypertension.

Do Adolescents With Insulin Resistance Demonstrate Impaired Heart Rate Recovery From Exercise?

Heart rate recovery (HRR) following maximal aerobic exercise can serve as a noninvasive method of analyzing the risk for cardiovascular diseases. Inability to recover heart rate to pre‐exercise values can indicate parasympathetic nervous system dysfunction. Poor HRR could also be an indicator of early mortality, as decreased ability to recover heart rate is linked to decreases in vagal tone. Insulin resistance (IR) has also been linked to diabetes, obesity, and parasympathic nervous system dysfunction in adults, through an increased ratio of sympathetic to parasympathetic nerve activity. However, it remains unknown if adolescents with IR exhibit similar parasympathetic dysfunction. Therefore, it was hypothesized that increased IR would be associated with decreased HRR in adolescents.Data were collected from adolescents aged 12‐18. Insulin resistance was quantified as HOMA‐IR using fasting glucose and insulin. Subjects underwent maximal aerobic exercise testing on a cycle ergometer pedaling at 60‐70 RPM, starting at 25 W and increasing 25 W every two minutes. The test was terminated when subjects could no longer maintain the pedaling cadence for 5 consecutive seconds. Following cessation of exercise, subjects remained seated without movement for a two‐minute recovery period. Heart rate (HR) was collected via three lead ECG. Data was filtered and resampled to 1 Hz. A linear regression model was applied to the first 30s of HRR data for each subject, with the resulting slope used as the output variable in a subsequent linear regression model with HOMA‐IR as the predictor. Significance was set p&lt;0.05.Subjects were 15 ± 2 years old with a HOMA‐IR 2.08 ± 1.92. The average HRR slope was ‐0.63 ± 0.13 BPM (r=‐0.91). The slope of HRR vs. HOMA‐IR was ‐0.02 ± 0.02 (r=‐0.32, p=0.18). The slope of HRR vs. fasting glucose was ‐0.001 ± 0.003 (r=‐0.07, p=0.8). The slope of HRR vs. fasting insulin was ‐0.008 ± 0.004 (r=‐0.42, p=0.08).Poor HRR has been linked to early mortality, and insulin resistance causes diabetes. However, IR and HRR were not found to have a statistically significant relationship. The relationships between HRR and fasting glucose and insulin levels were also not statistically significant. These data suggest there is no relationship between HRR and IR post exercise in adolescents.

Oxygen Uptake at Critical Speed and Power in Running: Perspectives and Practical Applications.

Intensity domains are recommended when prescribing exercise, and critical power/speed (CP/CS) was designated the "gold standard" when determining maximal metabolic steady state. CS is the running analog of CP for cycle ergometry. However, a CP for running could be useful for controlling intensity when training in any type of condition. Therefore, this study aimed to estimate external, internal, and total CP (CPext, CPint, and CPtot), obtained based on running power calculations, and verified whether they occurred at the same percentage of peak oxygen uptake as the usual CS. Furthermore, this study examined whether selecting strides at the start, half, or end of the exhaustive runs to calculate running power influenced the estimation of the 3 CPs. Thirteen male runners performed a maximal incremental aerobic test and 4 exhaustive runs (90%, 100%, 110%, 120% peak speed) on a treadmill. The estimations of CS and CPs were obtained using a 3-parameter mathematical model fitted using weighted least square. CS was estimated at 4.3m/s while the estimates of CPext, CPint, and CPtot were 5.2, 2.6, and 7.8W/kg, respectively. The corresponding V˙O2 for CS was 82.5 percentage of peak oxygen uptake and 81.3, 79.7, and 80.6 percentage of peak oxygen uptake for CPext, CPint, and CPtot, respectively. No systematic bias was reported when comparing CS and CPext, as well as the 3 different CPs, whereas systematic biases of 2.8% and 1.8% were obtained for the comparison among CS and CPint and CPtot, respectively. Nonetheless, the V˙O2 for CS and CPs were not statistically different (P = .09). Besides, no effect of the time stride selection for CPs as well as their resulting V˙O2 was obtained (P ≥ .44). The systematic biases among V˙O2 at CS and CPint and CPtot were not clinically relevant. Therefore, CS and CPs closely represent the same fatigue threshold in running. The knowledge of CP in running might prove to be useful for both athletes and coaches, especially when combined with instantaneous running power. Indeed, this combination might help athletes controlling their targeted training intensity and coaches prescribing a training session in any type of condition.

The influence of muscle strength and aerobic fitness on functional recovery in professional soccer players.

Well-developed physical qualities may protect athletes from exercise-induced muscle damage and accelerate recovery following exercise. This study examined the influence of muscle strength and aerobic fitness on recovery from competitive soccer matches. Fourteen players from the English Premier League 2 (age 18±1 years; height 1.78±0.54 m; mass 73.8±6.3 kg) were equally divided (median split) into a higher or lower group for muscle strength and aerobic fitness, according to their isometric mid-thigh pull (IMPT) and maximal aerobic speed test (MAST) scores, respectively. The following markers of recovery were assessed before (48-h prematch), 12 h (M+1), 36 h (M+2) and 60 h (M+3) after ~3 matches: countermovement jump height (CMJ), reactive strength index (RSI), muscle soreness (DOMS) and wellbeing. IMTP was positively correlated with the recovery of CMJ, RSI and DOMS following matches (P<0.05). In the high IMTP group, DOMS was lower at M+1 to M+3 (all P≤0.002; ES≥2.10), CMJ was ≥4% greater at M+1 to M+3 (all P≤0.001; ES≥2.21) and RSI was ≥3% higher at M+2 and M+3 (all P≤0037; ES≥1.25). Players in the H-MAST group did not recover quicker for any variable (all P>0.05). This study showed that stronger players recovered quicker after matches and highlights the importance of lower-body strength training for soccer players.

The effect of a decrease in stretch-shortening cycle function after cycling on subsequent running

ObjectivesIncreased cardiorespiratory responses and changes in muscle activity and running kinematics occur in running after cycling compared with isolated running. Nevertheless, little is known about the causes of these changes. Cycling exercise decreases the stretch-shortening cycle (SSC) function, which can influence subsequent running. This study aimed to clarify whether the decrease in SSC function after cycling causes cardiorespiratory and biomechanical changes in subsequent running. DesignCross-sectional laboratory study. Participants were divided into two groups based on SSC function: an SSC dec group (those with decreased SSC function after cycling) and an SSC non-dec group (those without decreased SSC function after cycling). MethodsEighteen participants (10 triathletes and 8 runners) completed maximal aerobic tests for running and cycling. After these sessions, a submaximal run-cycle-run test was performed to compare between control run (no preceding cycle) and transition run (preceded by cycling). A jump test was administered before and after the submaximal cycling. SSC function was calculated as the ratio of the jump height to the time spent in contact with the ground (reactive strength index). Gas exchange measures, heart rate, and gait parameters were collected throughout the test. ResultsOxygen uptake and ventilation were increased by cycling in the SSC dec group but not in the SSC non-dec group. In both groups, there were no significant differences in the gait parameters between control and transition runs. ConclusionsThe decrease in SSC function after cycling would increase cardiorespiratory responses in subsequent running.

Effect of Mathematical Modeling and Fitting Procedures on the Assessment of Critical Speed and Its Relationship With Aerobic Fitness Parameters.

An accurate estimation of critical speed (CS) is important to accurately define the boundary between heavy and severe intensity domains when prescribing exercise. Hence, our aim was to compare CS estimates obtained by statistically appropriate fitting procedures, i.e., regression analyses that correctly consider the dependent variables of the underlying models. A second aim was to determine the correlations between estimated CS and aerobic fitness parameters, i.e., ventilatory threshold, respiratory compensation point, and maximal rate of oxygen uptake. Sixteen male runners performed a maximal incremental aerobic test and four exhaustive runs at 90, 100, 110, and 120% of the peak speed of the incremental test on a treadmill. Then, two mathematically equivalent formulations (time as function of running speed and distance as function of running speed) of three different mathematical models (two-parameter, three-parameter, and three-parameter exponential) were employed to estimate CS, the distance that can be run above CS (d′), and if applicable, the maximal instantaneous running speed (smax). A significant effect of the mathematical model was observed when estimating CS, d′, and smax (P < 0.001), but there was no effect of the fitting procedure (P > 0.77). The three-parameter model had the best fit quality (smallest Akaike information criterion) of the CS estimates but the highest 90% confidence intervals and combined standard error of estimates (%SEE). The 90% CI and %SEE were similar when comparing the two fitting procedures for a given model. High and very high correlations were obtained between CS and aerobic fitness parameters for the three different models (r ≥ 0.77) as well as reasonably small SEE (SEE ≤ 6.8%). However, our results showed no further support for selecting the best mathematical model to estimate critical speed. Nonetheless, we suggest coaches choosing a mathematical model beforehand to define intensity domains and maintaining it over the running seasons.

Cardiovascular, Cellular, and Neural Adaptations to Hot Yoga versus Normal-Temperature Yoga.

Context: Chronic heat exposure promotes cardiovascular and cellular adaptations, improving an organism's ability to tolerate subsequent stressors. Heat exposure may also promote neural adaptations and alter the neural–hormonal stress response. Hot-temperature yoga (HY) combines mind–body exercise with heat exposure. The added heat component in HY may induce cardiovascular and cellular changes, along with neural benefits and modulation of stress hormones.Aims: The purpose of the present study is to compare the cardiovascular, cellular heat shock protein 70 (HSP70), neural, and hormonal adaptations of HY versus normal-temperature yoga (NY).Settings and Design: Twenty-two subjects (males = 11 and females = 11, 26 ± 6 years) completed 4 weeks of NY (n = 11) or HY (n = 11, 41°C, 40% humidity). Yoga sessions were performed 3 times/week following a modified Bikram protocol.Subjects and Methods: Pre- and posttesting included (1) hemodynamic measures during a heat tolerance test and maximal aerobic fitness test; (2) neural and hormonal adaptations using serum brain-derived neurotrophic factor (BDNF) and adrenocorticotropic hormone (ACTH), along with a mental stress questionnaire; and (3) cellular adaptations (HSP70) in peripheral blood mononuclear cells (PBMCs).Statistical Analysis: Within- and between-group Student's t-test analyses were conducted to compare pre- and post-VO2 max, perceived stress, BDNF, HSP70, and ACTH in HY and NY groups.Results: Maximal aerobic fitness increased in the HY group only. No evidence of heat acclimation or change in mental stress was observed. Serum BDNF significantly increased in yoga groups combined. Analysis of HSP70 suggested higher expression of HSP70 in the HY group only.Conclusions: Twelve sessions of HY promoted cardiovascular fitness and cellular thermotolerance adaptations. Serum BDNF increased in response to yoga (NY + HY) and appeared to not be temperature dependent.

Isolated Knee Extensor Exercise Training Improves Skeletal Muscle Vasodilation, Blood Flow and Functional Capacity in HFpEF Patients

Background Patients with HFpEFexperience severe exercise intolerance due in part to impaired skeletal muscle vascular function during exercise. Whole body exercise interventions yield only modest improvements in cardiac function and functional capacity, and are often not well-tolerated due to severe dyspnea. Therefore, training interventions that isolate smaller muscle groups to improve vascular function may be effective at improving exercise capacity in HFpEF patients while minimizing shortness of breath. Hypothesis Eight weeks of isolated knee extension (KE) exercise training will improve leg blood flow and increase exercise capacity in patients with HFpEF. Methods Nine HFpEF patients (66±5 years, 6 females) performed graded KE exercise (5, 10, and 15W) and maximal aerobic exercise testing (cycle ergometer) before and after 8 weeks of isolated KE training (3x per week, 30 min per leg). Vascular function was assessed by measuring skeletal muscle blood flow (femoral artery ultrasound), mean arterial pressure (ECG-gated sphygmomanometer), and femoral vascular conductance (FVC; index of vasodilation) during graded KE exercise. Functional capacity, quantified as peak pulmonary oxygen uptake (V̇O2, Douglas bags), peak cardiac output (Qc, acetylene rebreathing) and arterial-venous oxygen difference (a-v O2 diff) were measured during a graded maximal cycle exercise to assess cardiac and peripheral adaptations to isolated KE training. Results Eight weeks of isolated KE training lowered blood pressure (Δ: pre: 22±13, post: 12±10.1 mmHg; P=0.02) and improved blood flow (Δ: pre: 950±332, post: 1263±355 ml/min; P=0.02) during 15W isolated KE exercise. The increase in blood flow was due to improved skeletal muscle vasodilation (ΔFVC: pre: 810±417, post: 1234±347 ml/min/100mmHg; P=0.01). During maximal exercise testing, KE training had a small but variable effect on peak Qc (pre: 12.5±3.7, post: 13.2±3.9 l/min; P=0.19), and peripheral oxygen extraction (a-v O2 diff: pre: 10.6±1.8, post: 11.0±1.7 ml/100ml; P=0.17), but resulted in a 13% improvement in peak V̇O2 (pre:12.5±5.5, post: 14.0±6.0; P=0.01). Conclusions Eight weeks of isolated KE training improved skeletal muscle vascular function and blood flow delivery during KE exercise, resulting in improved functional capacity in patients with HFpEF. Exercise interventions aimed at increasing skeletal muscle and vascular function may be effective therapeutic options for HFpEF patients that experience severe dyspnea during whole body exercise.