Bicycle Exercise Research Articles

Fast and Slow Jump Training Methods Induced Similar Improvements in Measures of Physical Fitness in Young Females

This study aimed to contrast the impacts of an exercise intervention using either bounce drop jump (DJ; fast stretch-shortening cycle exercise) or countermovement jump (CMJ; slow stretch-shortening cycle exercise) on measures of physical fitness in young females. A total of 23 young females (age: 19.7 ± 1.0 years, height: 159.8 ± 4.2 cm, body mass: 54.3 ± 14.3 kg) were randomly assigned to either DJ (n = 12) or CMJ (n = 11) training, which spanned 6 weeks. Pre- and posttraining assessments were conducted for 10 m and 30 m linear sprints, change-of-direction speed, CMJ, DJ (jump height, contact time, and reactive strength index), standing long jump, triple-hop distance, and isometric strength. Apart from the variance in jump technique, both interventions were standardized in terms of total repetitions, intensity, and surface type. No significant Group × Time effect was observed in any dependent variables (all p > .05). A significant time effect was observed in 10 m (p < .001, effect size [ES] = 0.70) and 30 m (p < .001, ES = 0.79) linear sprint, CMJ height (p = .012, ES = 0.34), DJ contact time (p = .012, ES = 0.34), and triple-hop distance (p = .006, ES = 0.38). Both DJ and CMJ training interventions led to comparable improvements in linear sprints, CMJ height, DJ contact time, and triple-hop distance. These findings suggest that the duration of ground contact during intervention exercises (i.e., fast vs. slow stretch-shortening cycle) did not significantly influence initial (6 weeks) physical fitness adaptations in young females. However, extending these results to highly trained groups (e.g., athletes) warrants further investigation.

Muscle Oxygen Dynamics Measured by NIRS.

Near-infrared spectroscopy (NIRS) has been used to measure skeletal muscle oxidative function for more than 30years. Several indicators evaluate muscle oxidative function using NIRS during exercise, such as deoxygenation rate at the start of exercise (Deoxy-rate), changes in deoxygenation during exercise (ΔDeoxy), and reoxygenation speed after exercise (T1/2 reoxy, reoxy rate). Previous studies have reported that these muscle NIRS indicators are significantly correlated with muscle fibre type, phosphocreatine recovery rate, and peak oxygen uptake. In addition, muscle NIRS indicators have been applied to the study of a number of chronic health conditions, including patients with ischaemic heart failure. Recently, wearable NIRS devices monitor muscle function continuously and freely in the field, and we predict that NIRS devices will be widely applied to our lifestyles more than ever before. However, there are some critical problems with measuring muscle oxidative function using NIRS devices. We have previously reported that subcutaneous adipose tissue thickness (SATT) greatly influences the light pathlength and makes it difficult to quantify tissue deoxygenation, especially in the measurements of muscle deoxygenation from the skin surface. The effects of SATT need to, therefore, be corrected when using NIRS devices, especially when comparing differences in sex, age, and trainability, as the subjects' SATT could differ significantly. In addition, we have more recently reported that assuming constant mean pathlength (MPL) in NIRS leads to an inaccurate interpretation of muscle deoxygenation, since there are greater changes in MPL during incremental cycling exercise, especially at shorter wavelengths in the NIRS region. In this mini-review, we will summarise the indicators of muscle oxidative function using NIRS and the challenges of using an NIRS apparatus, especially during exercise.

Maximum Phonation Time as a Predictor of Lactate Threshold during Intermittent Incremental Endurance Test.

The aim of the present study was to examine whether the exercise intensity corresponding to the lactate threshold may be predicted by the Maximum Phonation Time task (MPT). Ten Greek amateur football players (age: 18.4 ± 1.0 years), performed a graded cycling exercise test to exhaustion in order to determine lactate threshold. A number of physiological variables were measured including perceived exertion, cardiopulmonary values and blood lactate. The MPT variable was correlated with all of the physiological variables. Also, a binary logistic regression analysis was used to investigate whether MPT could predict lactate threshold. The ROC analysis showed specificity to be 0.90 and sensitivity to be 0.70 (optimal screening cutoff point for MPT 9.5 seconds). The results showed an odds ratio of 1.45 indicating a 45% increase in the probability of passing the threshold for every second there was a reduction in voice duration. MPT may be used as a simple, non-invasive, inexpensive method for monitoring exercise intensity during physical exercise. Further research is needed to measure its efficacy in bigger samples and in different sports.

Cold Ambient Temperature Does Not Alter Subcutaneous Abdominal Adipose Tissue Lipolysis and Blood Flow in Endurance-Trained Cyclists

This study sought to investigate the effect of cold ambient temperature on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and blood flow during steady-state endurance exercise in endurance-trained cyclists. Ten males (age: 23 ± 3 years; peak oxygen consumption: 60.60 ± 4.84 ml·kg−1·min−1; body fat: 18.4% ± 3.5%) participated in baseline lactate threshold (LT) and peak oxygen consumption testing, two familiarization trials, and two experimental trials. Experimental trials consisted of cycling in COLD (3 °C; 42% relative humidity) and neutral (NEU; 19 °C; 39% relative humidity) temperatures. Exercise consisted of 25 min cycling at 70% LT and 25 min at 90% LT. In situ SCAAT lipolysis and blood flow were measured via microdialysis. Heart rate, core temperature, carbohydrate and fat oxidation, blood glucose, and blood lactate were also measured. Heart rate, core temperature, oxygen consumption, and blood lactate increased with exercise but were not different between COLD and NEU. SCAAT blood flow did not change from rest to exercise or between COLD and NEU. Interstitial glycerol increased during exercise (p < .001) with no difference between COLD and NEU. Fat oxidation increased (p < .001) at the onset of exercise and remained elevated thereafter with no difference between COLD and NEU. Carbohydrate oxidation increased with increasing exercise intensity and was greater at 70% LT in COLD compared to NEU (p = .030). No differences were observed between conditions for any other variable. Cycling exercise increased SCAAT lipolysis but not blood flow. Ambient temperature did not alter SCAAT metabolism, SCAAT blood flow, or fat oxidation in well-trained cyclists, though cold exposure increased whole-body carbohydrate oxidation at lower exercise intensities.

Wearable near-infrared spectroscopy: reliability and sensitivity among different endurance cycling exercise intensities.

The present study investigated the reliability and sensitivity of a wearable near-infrared spectroscopy (wNIRS) device in moderate and heavy exercise intensity domains. On three separate days, eleven males performed an incremental test to exhaustion, and in the following visits, four submaximal constant-load bouts (i.e., test and retest) were performed in the moderate-intensity domain (100 and 130 W) and heavy-intensity domain (160 and 190 W). The local tissue oxygen saturation index (SmO2) and pulmonary oxygen uptake (V̇O2) were measured continuously. The absolute SmO2 and V̇O2 values and the change (Δ) from the 3rd to 6th min of exercise were calculated. There was good reliability for SmO2 measurements, as indicated by the high intraclass correlation coefficient analysis (ICC ≥0.84 for all) and low coefficient of variation between the two trials (CV ≤4.1% for all). Steady-state responses were observed for SmO2 and V̇O2 from the 3rd to the 6th min in the two moderate-intensity bouts (P>0.05), whereas SmO2 decreased and V̇O2 increased from the 3rd to the 6th min in the two heavy-intensity bouts (P<0.05). Together, these findings suggested that the SmO2 measured with a wNIRS device is reliable and sensitive to track local metabolic changes provoked by slight increments in exercise intensity.

The effect of normobaric hypoxia on acute exercise-induced changes in blood sphingoid base-1-phosphates metabolism in cyclists.

Extracellular sphingosine-1-phosphate (S1P) emerged as an important regulator of muscle function. We previously found that plasma S1P concentration is elevated in response to acute exercise and training. Interestingly, hypoxia, which is commonly utilized in training programs, induces a similar effect. Therefore, the aim of the current study was to determine the effect of normobaric hypoxia on exercise-induced changes in blood sphingolipid metabolism. Fifteen male competitive cyclists performed a graded cycling exercise until exhaustion (GE) and a simulated 30 km individual time trial (TT) in either normoxic or hypoxic (FiO2 = 16.5%) conditions. Blood samples were taken before the exercise, following its cessation, and after 30 min of recovery. We found that TT increased dihydrosphingosine-1-phosphate (dhS1P) concentration in plasma (both HDL- and albumin-bound) and blood cells, as well as the rate of dhS1P release from erythrocytes, regardless of oxygen availability. Plasma concentration of S1P was, however, reduced during the recovery phase, and this trend was augmented by hypoxia. On the other hand, GE in normoxia induced a selective increase in HDL-bound S1P. This effect disappeared when the exercise was performed in hypoxia, and it was associated with reduced S1P level in platelets and erythrocytes. We conclude that submaximal exercise elevates total plasma dhS1P concentration via increased availability of dihydrosphingosine resulting in enhanced dhS1P synthesis and release by blood cells. Maximal exercise, on the other hand, induces a selective increase in HDL-bound S1P, which is a consequence of mechanisms not related to blood cells. We also conclude that hypoxia reduces post-exercise plasma S1P concentration.

Development of Smart Gloves Prototype for Cyclists

Smart technologies have set their own standards and made their way into the current period. In that way, smart gloves have their own reputation for various purposes, such as gaming, boxing, power lifting, etc. However, there are not many smart gloves exclusively for cyclists in the market. Smart gloves for cyclists would be beneficial for monitoring their vitals during the athletic training or tracking their activity. There are few highly expensive wearable activity monitors that results in detecting the abnormal health status before it affects the athlete, during cycling and resistance exercise. In this paper, a smart glove prototype for cyclists is developed using Arduino software with affordable price, accurate reading of the heart rate, and oxygen-saturated level in the blood using MAX30100 sensor. The GPS enables locating and detecting the location of the user during the cycling activities. The determined data will be displayed on the Android smart phone of the user with the support of Bluetooth connection. The values can be monitored in real time, benefiting the user to act accordingly to the values in case of any significant abnormalities seen during the cycling activity. MIT app inventor had contributed a great part in accomplishing the mobile application for monitoring. As a result, in this study the developed prototype compensates the limitations of the existing smart glove and in cooperated it for serving its purpose at an affordable price.

Comparison of Low-intensity Aerobic Exercise with Assisted Bicycle Exercise on Quality of Life and Lung Function in Duchenne Muscular Dystrophy

Comparison of Low-intensity Aerobic Exercise with Assisted Bicycle Exercise on Quality of Life and Lung Function in Duchenne Muscular Dystrophy

THE EFFECT OF IN-BED LEG CYCLING EXERCISES ON MUSCLE STRENGTH IN PATIENTS WITH INTENSIVE CARE UNIT-ACQUIRED WEAKNESS: A SINGLE-CENTER RETROSPECTIVE STUDY.

To examine the effect of in-bed leg cycling exercise on patients with intensive care unit-acquired weakness (ICU-AW). Single-center retrospective study. Patients admitted to the ICU between January 2019 and March 2023 were enrolled in the ergometer group, and those admitted to the ICU between August 2017 and December 2018 were enrolled in the control group. The ergometer group performed in-bed leg cycling exercises 5 times per week for 20 min from the day of ICU-AW diagnosis. Furthermore, the ergometer group received 1 early mobilization session per day according to the early mobilization protocol, whereas the control group received 1 or 2 sessions per day. The number of patients with recovery from ICU-AW at ICU discharge and improvement in physical functions were compared. Significantly more patients in the ergometer group recovered from ICU-AW than in the control group (87.0% vs 60.6%, p = 0.039). Regarding physical function, the ergometer group showed significantly higher improvement efficiency in Medical Research Council sum score (1.0 [0.7-2.1] vs 0.1 [0.0-0.2], p < 0.001). In-bed leg cycling exercise, in addition to the early mobilization protocol, reduced the number of patients with ICU-AW at ICU discharge.

Cadence Modulation during Eccentric Cycling Affects Perception of Effort But Not Neuromuscular Alterations.

A recent study showed that cadence modulation during short eccentric cycling exercise affects oxygen consumption (V̇O 2 ), muscular activity (EMG), and perception of effort (PE). This study examined the effect of cadence on V̇O 2 , EMG, and PE during prolonged eccentric cycling and exercise-induced neuromuscular alterations. Twenty-two participants completed three sessions 2-3 wk apart: 1) determination of the maximal concentric peak power output, familiarization with eccentric cycling at two cadences (30 and 60 rpm at 60% peak power output), and neuromuscular testing procedure; 2) and 3) 30 min of eccentric cycling exercise at a cadence of 30 or 60 rpm. PE, cardiorespiratory parameters, and vastus lateralis and rectus femoris EMG were collected during exercise. The knee extensors' maximal voluntary contraction torque, the torque evoked by double stimulations at 100 Hz (Dt100) and 10 Hz (Dt10), and the voluntary activation level were evaluated before and after exercise. V̇O 2 , EMG, and PE were greater at 30 than 60 rpm (all P < 0.05). Maximal voluntary contraction torque, evoked torque, and Dt10/Dt100 ratio decreased (all P < 0.01) without cadence effect (all P > 0.28). Voluntary activation level remained constant after both eccentric cycling exercises ( P = 0.87). When performed at the same power output, eccentric cycling exercise at 30 rpm elicited a greater PE, EMG, and cardiorespiratory demands than pedaling at 60 rpm. Exercise-induced fatigability was similar in both eccentric cycling conditions without neural impairments, suggesting that eccentric cycling seemed to alter more specifically muscular function, such as the excitation-contraction coupling process. In a rehabilitation context, eccentric cycling at 60 rpm seems more appropriate because it will induce lower PE for similar strength loss compared with 30 rpm.

Biosensor for Rapid Measurement of Lactate in Exhaled Breath Condensate

Lactate concentration plays an important role in disease diagnostics. Higher lactate concentrations are associated with sepsis and septic shock [2], trauma [3], tissue hypoxia due to acute lung injury [4], and respiratory diseases [5]. Lactate level is also widely used in monitoring athletes’ training and fitness as long-term exhausting exercise leads to a rapid increase in lactate level and result in muscle weakening and fatigue [6]. Compared with the traditional blood sample media which is invasive and capillary blood monitoring is not suitable for routine clinical use, the exhaled breath condensate (EBC) is simple and non-invasive method with no potential for adverse effects for lactate analysis.In this presentation, a point-of-care electrochemical biosensor is introduced for the EBC lactate analysis. This disposable and low-cost sensor is aimed to be inserted in an EBC collection device developed by our team that enables real-time monitoring and rapid measurements of EBC lactate level. The sensor measurement is done directly after EBC sample collection, that minimizes the risk of sample degradation and is cheaper than the traditional laboratory techniques such as fluorometry or mass spectrometry.The sensor is modified with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), Prussian blue (PB) and lactate oxidase (LOD) enzyme. Lactate concentration is measured from amperometric current response generated by the redox reactions on sensor surface. The enzyme gel formulation is optimized based on rotating disk electrode (RDE) experiments and kinetics analysis, investigating the effect of LOD concentration and gel thickness, and was then applied to disposable sensors.Finally, human EBC analysis is conducted on healthy subjects at rest and after 30 min of intense aerobic cycling exercise. Sensor’s results in real EBC lactate measurements demonstrate a good correlation with fluorometry and mass spectrometry calibrations and exhibit high stability and sensitivity in both short-term and long-term use. Mass production of the sensor is done by robotic gel dispensing using a Biodot aspirate dispensing machine.Note: This presentation is based on the corresponding author's recent publication ‘Rapid Measurement of Lactate in the Exhaled Breath Condensate: Biosensor Optimization and In-Human Proof of Concept’ in ACS Sensors (doi.10.1021/acssensors.2c01739) [1]

Evaluation of salivary α-amylase and immunoglobulin A responses after endurance exercise in adolescent males and females with similar aerobic fitness.

The objective of this study was to clarify whether there are sex-specific differences in salivary α-amylase and immunoglobulin A responses following acute endurance exercise in adolescent males and females with equivalent cardiorespiratory fitness levels. Twenty-six aerobically trained adolescent males and females with similar training status were enrolled in this study. Each individual executed a 1-h prolonged cycling exercise corresponding to a constant power output at 65% of peak oxygen uptake. Unstimulated whole salivary samples were taken with the passive drooling method at the 10-min period before and after exercise for the determination of salivary responses [α-amylase, immunoglobulin A, total protein and flow rate]. Salivary α-amylase activity, immunoglobulin A concentration and total protein concentration were significantly augmented immediately after acute endurance exercise. Regarding sex differences, only the salivary flow rate was significantly lower in females than in males. The findings of the present study imply that adolescent males and females appear to have similar salivary responses after acute endurance exercise, as represented by salivary α-amylase activity and immunoglobulin A concentration in connection with total protein concentration and salivary flow rate, when they are matched for peak oxygen uptake relative to fat-free body mass.

Peripheral hypercapnic chemosensitivity at rest and progressive exercise intensities in males and females.

Peripheral hypercapnic chemosensitivity (PHC) is the ventilatory response to hypercapnia and is enhanced with acute whole-body exercise. However, little is known about the mechanism(s) responsible for the exercise related increase in PHC and if progressive exercise leads to further augmentation. We hypothesized that unloaded cycle exercise (0W) would increase PHC but progressively increasing the intensity would not further augment the response. Twenty healthy subjects completed 2 testing days. Day 1 was a maximal exercise test on a cycle ergometer to determine peak power output (Wmax). Day 2 consisted of six 12-minute stages: (i) rest on chair, (ii) rest on bike, (iii) 0W unloaded cycling, (iv) 25% Wmax, (v) 50% Wmax, and (vi) ~70% Wmax with ~10 min of rest between each exercise stage. In each stage, PHC was assessed via 2 breaths of 10% CO2 (~21% O2) repeated 5 times with ~45s between each to ensure end-tidal CO2 (PETCO2) and ventilation returned to baseline. Pre-stimulus PETCO2 was not different between rest and unloaded cycling (p=0.478). There was a significant increase in PHC between seated rest and 25% Wmax (0.71±0.37 vs. 1.03±0.52 LmmHg-1min-1, respectively p=0.0006), and between seated rest and unloaded cycling (0.71±0.37 vs. 1.04±0.4 LmmHg-1min-1, respectively p=0.0017). There was no effect of exercise intensity on PHC (1.03±0.52 vs. 0.95±0.58 vs. 1.01±0.65 LmmHg-1min-1for 25, 50 and 70% Wmax, p=0.44). The increased PHC response from seated rest to unloaded and 25% Wmax, but no effect of exercise intensity suggests a possible feedforward/feedback mechanism causing increased PHC sensitivity through the act of cycling.

Exploratory assessment of right ventricular structure and function during prolonged endurance cycling exercise

BackgroundA reduction in right ventricular (RV) function during recovery from prolonged endurance exercise has been documented alongside RV dilatation. A relative elevation in pulmonary artery pressure and therefore RV afterload during exercise has been implicated in this post-exercise dysfunction but has not yet been demonstrated. The current study aimed to assess RV structure and function and pulmonary artery pressure before, during and after a 6-h cycling exercise bout.MethodsEight ultra-endurance athletes were recruited for this study. Participants were assessed prior to exercise supine and seated, during exercise at 2, 4 and 6 h whilst cycling seated at 75% maximum heart rate, and post-exercise in the supine position. Standard 2D, Doppler and speckle tracking echocardiography were used to determine indices of RV size, systolic and diastolic function.ResultsHeart rate and RV functional parameters increased from baseline during exercise, however RV structural parameters and indices of RV systolic and diastolic function were unchanged between in-exercise assessment points. Neither pulmonary artery pressures (26 ± 9 mmHg vs 17 ± 10 mmHg, P > 0.05) nor RV wall stress (7.1 ± 3.0 vs 6.2 ± 2.4, P > 0.05) were significantly elevated during exercise. Despite this, post-exercise measurements revealed RV dilation (increased RVD1 and 3), and reduced RV global strain (− 21.2 ± 3.5 vs − 23.8 ± 2.3, P = 0.0168) and diastolic tissue velocity (13.8 ± 2.5 vs 17.1 ± 3.4, P = 0.019) vs pre-exercise values.ConclusionA 6 h cycling exercise bout at 75% maximum heart rate did not alter RV structure, systolic or diastolic function assessments during exercise. Pulmonary artery pressures are not elevated beyond normal limits and therefore RV afterload is unchanged throughout exercise. Despite this, there is some evidence of RV dilation and altered function in post-exercise measurements.

Acute high-intensity interval exercise improves food-related cognition in young adults with obesity: An ERP study

Purpose Cognitive function, particularly food-related cognition, is critical for maintaining a healthy weight and preventing the acceleration of obesity. High-Intensity Interval Exercise (HIIE) is an increasingly popular form of exercise and has been shown to improve physical fitness and cognitive function. However, there is limited research on the effects and underlying mechanisms of HIIE on general and food-related cognition among adults with obesity. The aim of the current study was to examine the influence of a single bout of HIIE on food-related cognition among young adults with obesity.Methods Fifteen young men with obesity (BMI = 33.88 ± 4.22, age = 24.60 ± 5.29 years) were recruited. Participants took part in a HIIE condition consisting of 30 minutes of stationary cycle exercise (5-min warm-up, 20-min HIIE and 5-min cool down), and a control session consisting of a time and attention-matched period of sedentary rest in a counterbalanced order. Behavioral (reaction time and accuracy) and event-related potential measures (P3 and the late positive potential, LPP) elicited during a food-related Flanker task were measured after the HIIE and control session.Results Shorter response times were observed following HIIE, regardless of congruency or picture type, with no change in accuracy. Increased P3 and LPP amplitudes were observed following HIIE relative to the control session.Conclusion The findings suggest a single bout of HIIE has a beneficial effect on general and food-related cognition among young adults with obesity, with increased recruitment of cognitive resources to support cognitive control. Future research is warranted to examine the dose-response relationship between acute bouts or longer participation in HIIE on food-related cognition in obesity.

Essential amino acid supplements ingestion has a positive effect on executive function after moderate-intensity aerobic exercise

Aerobic exercise acutely improves cognitive function (e.g., executive function (EF); memory recognition (MR)) and increases circulating brain-derived neurotrophic factor (BDNF). In addition, branched-chain amino acids (BCAA) ingestion acutely shortens the choice reaction time and increases brain BDNF. We examined whether the ingestion of essential amino acid (EAA) supplements (mainly composed of BCAA) would positively impact on cognitive function and circulating BDNF after moderate-intensity aerobic exercise. Twenty-two healthy young men received either an EAA supplements or the placebo (PL) 30 min before undergoing aerobic exercise. The participants performed a cycling exercise at 60% of peak oxygen uptake for 30 min. EF after aerobic exercise was better after the EAA treatment than after the PL treatment (P = 0.02). MR (P = 0.38 for response accuracy; P = 0.15 for reaction time) and circulating BDNF (P = 0.59) were not altered by EAA supplements. EF improvement was correlated with increases in some amino acids (leucine, isoleucine, valine, lysine, phenylalanine; all Ps < 0.05) that are potential substrates for synthesizing neurotransmitters in the brain. These results suggest that EAA supplements ingestion had a positive effect on EF after moderate-intensity aerobic exercise, while MR and BDNF were not altered.

Home-based arm cycling exercise improves trunk control in persons with incomplete spinal cord injury: an observational study

Arm cycling is used for cardiorespiratory rehabilitation but its therapeutic effects on the neural control of the trunk after spinal cord injury (SCI) remain unclear. We investigated the effects of single session of arm cycling on corticospinal excitability, and the feasibility of home-based arm cycling exercise training on volitional control of the erector spinae (ES) in individuals with incomplete SCI. Using transcranial magnetic stimulation, we assessed motor evoked potentials (MEPs) in the ES before and after 30 min of arm cycling in 15 individuals with SCI and 15 able-bodied controls (Experiment 1). Both groups showed increased ES MEP size after the arm cycling. The participants with SCI subsequently underwent a 6-week home-based arm cycling exercise training (Experiment 2). MEP amplitudes and activity of the ES, and movements of the trunk during reaching, self-initiated rapid shoulder flexion, and predicted external perturbation tasks were measured. After the training, individuals with SCI reached further and improved trajectory of the trunk during the rapid shoulder flexion task, accompanied by increased ES activity and MEP amplitudes. Exercise adherence was excellent. We demonstrate preserved corticospinal drive after a single arm cycling session and the effects of home-based arm cycling exercise training on trunk function in individuals with SCI.

Anaerobic and aerobic contributions to repeated supramaximal cycling exercises and their adaptation to high-intensity interval training in obese perimenopausal and postmenopausal women.

This study investigated the anaerobic and aerobic contributions to total energy release during repeated supramaximal cycling exercises (SCE) and their adaptation in response to 6 weeks of high-intensity interval training (HIIT) in obese perimenopausal and postmenopausal women. Nineteen perimenopausal women and 21 postmenopausal women with an average age of 50.1 years participated in the 6-week HIIT intervention. Before and after the training, the accumulated oxygen deficits (mL·min -1 ) and anaerobic and aerobic contributions (%) were measured in all groups via repeated SCE. The results showed that, before training, the anaerobic contributions to repeated SCE did not differ between the perimenopausal and postmenopausal women for the first three repetitions. However, a higher decrease was reported for postmenopausal women at the fourth and fifth repetitions ( P < 0.01, respectively). After HIIT, anaerobic contributions increased significantly in both groups ( P < 0.01, respectively). Nevertheless, postmenopausal women still had significantly lower anaerobic contributions to repeated SCE compared with perimenopausal women ( P < 0.01, respectively). Multiple linear regression analysis indicated that menopause status was an independent predictor of anaerobic contribution, accounting for 17%, 21%, 15%, 19%, and 22% of variations (β = 0.28, P = 0.03; β = 0.29, P = 0.04; β = 0.18, P = 0.05; β = 0.22, P = 0.05; and β = 0.33, P = 0.03 for the first to the fifth repetitions consecutively for perimenopausal vs postmenopausal groups). A 6-week HIIT intervention increased the anaerobic contributions to energy in response to repeated SCE in obese perimenopausal and postmenopausal women. However, postmenopausal women had lower anaerobic contributions at the fourth and fifth repetitions mainly due to the effects of menopause.

The human skeletal muscle metaboreflex contribution to cardiorespiratory control in males and females in dynamic exercise.

There is a significant effect of sex and muscle mass on the cardiorespiratory response to the skeletal muscle metaboreflex during isometric exercise. We therefore tested the hypothesis that sex differences would be present when isolated following dynamic exercise. We also tested the hypothesis that single and double leg post-exercise circulatory occlusion (PECO) following heavy exercise would elicit a cardiorespiratory response proportional to the absolute muscle mass. Healthy (24±4 years) males (n=10) and females (n=10) completed pulmonary function and an incremental cycle test to exhaustion. Participants completed two randomized, 6 min bouts of intense cycle exercise (84±7% V̇O2peak). One exercise bout was immediately followed by 3 min PECO (220mmHg) of the legs while the other exercise bout was followed by passive recovery. Males completed an additional session of testing with single leg PECO. The mean arterial pressure during PECO and control was greater in males compared to females (p=0.004). The was a significant time by condition by sex interaction in the heart rate response to PECO (p=0.027). There was also a significant condition by sex interaction in the ventilatory response to PECO (p=0.026). In males, we observed a dose-dependent cardiovascular, but not ventilatory, response to muscle mass occluded (all p<0.05). Our findings suggest the metaboreflex contribution to cardiorespiratory control during dynamic exercise is greater in males compared to females. The ventilatory response induced by double-leg occlusion but not single-leg occlusion, suggests that the ventilatory influence of the metaboreflex is less sensitive than the cardiovascular response and may be linked to the greater afferent activation induced by double-leg occlusion.

Aktivitas Olahraga Rekreasi di Komplek Perumahan Graha Padma Semarang dalam Pemenuhan Kebutuhan Masyarakat Tahun 2021

This study aims to describe and examine the types of weekend recreational sports activities, a form of fulfilling the needs of weekend recreational sports activities, as well as the environmental potential that can be accessed by the weekend sports community in the Graha Padma housing complex, Semarang. This research approach is a qualitative approach with a descriptive design. Data collection techniques using observation, interviews, and documentation. Narrative data analysis technique with data reduction steps, data presentation, and conclusions. The results of the research on the types of weekend recreational sports activities in the Graha Padma housing complex, Semarang, showed diversity, including walking, jogging, cycling, playing, and aerobic exercise. Fulfillment of the values ​​of community needs that are manifested from weekend recreational sports activities include the fulfillment of physiological needs, security needs, social needs, esteem needs, and self-actualization needs. The conclusions of this study are 1) The most popular type of sports activity is walking, which is the most favored by the perpetrators because it is easy, lively, and affordable. 2) The form of fulfillment of the most common needs, especially the level of physiological, safety, and social needs. 3) The potential of the environment is easy to reach, safe, comfortable, beautiful, and available areas for weekend sports activities.