cycle ergometer
Recently Published Documents


TOTAL DOCUMENTS

1341
(FIVE YEARS 256)

H-INDEX

80
(FIVE YEARS 4)

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 144
Author(s):  
Hun-Young Park ◽  
Jeong-Weon Kim ◽  
Sang-Seok Nam

We compared the effects of metabolic, cardiac, and hemorheological responses to submaximal exercise under light hypoxia (LH) and moderate hypoxia (MH) versus normoxia (N). Ten healthy men (aged 21.3 ± 1.0 years) completed 30 min submaximal exercise corresponding to 60% maximal oxygen uptake at normoxia on a cycle ergometer under normoxia (760 mmHg), light hypoxia (596 mmHg, simulated 2000 m altitude), and moderate hypoxia (526 mmHg, simulated 3000 m altitude) after a 30 min exposure in the respective environments on different days, in a random order. Metabolic parameters (oxygen saturation (SPO2), minute ventilation, oxygen uptake, carbon dioxide excretion, respiratory exchange ratio, and blood lactate), cardiac function (heart rate (HR), stroke volume, cardiac output, and ejection fraction), and hemorheological properties (erythrocyte deformability and aggregation) were measured at rest and 5, 10, 15, and 30 min after exercise. SPO2 significantly reduced as hypoxia became more severe (MH > LH > N), and blood lactate was significantly higher in the MH than in the LH and N groups. HR significantly increased in the MH and LH groups compared to the N group. There was no significant difference in hemorheological properties, including erythrocyte deformability and aggregation. Thus, submaximal exercise under light/moderate hypoxia induced greater metabolic and cardiac responses but did not affect hemorheological properties.


2022 ◽  
Vol 2022 ◽  
pp. 1-13
Author(s):  
Yaser Masoumi-Ardakani ◽  
Hamid Najafipour ◽  
Hamid Reza Nasri ◽  
Soheil Aminizadeh ◽  
Shirin Jafari ◽  
...  

Objectives. Hypertension (HTN) is one of the most important risk factors for cardiovascular diseases. Despite advances in treatment and control of HTN, the prevalence of HTN is still increasing. MitoQ is a supplement that acts on mitochondria and attenuates reactive oxygen species (ROS), which plays an important role in cardiovascular health. miRNAs play an important role in the pathophysiology of HTN. We evaluated the effects of MitoQ supplementation and endurance training (ET), alone and in combination, on functional indices of the heart and serum levels of miR-126, miR-27a, antioxidants, and NO, in patients with HTN. Methods. In a double-blind randomized clinical trial, 52 male participants (age 40-55 years) were randomly divided into four groups ( n = 13 ) of placebo, MitoQ (20 mg/day, oral), ET (cycle ergometer, moderate intensity, 40-60% VO2 peak, heart rate 120-140 b/min, 45 min a day, three days/week for six weeks), and MitoQ+ET. Cardiac function indices were assessed by echocardiography before and after interventions. Results. Systolic blood pressure (SBP) significantly decreased in all intervention groups ( P < 0.001 ) while DBP ( P < 0.01 ) and LV hypertrophy ( P < 0.05 ) were significantly decreased only in the MitoQ+ET group. Serum levels of SOD, GPx, and NO and the level of miR-126 significantly increased in all treatment groups, while miR-27a reduced in the ET ( P < 0.05 ) and MitoQ+ET ( P < 0.01 ) groups. Conclusions. Compared to MitoQ and ET alone, their combination has more prominent improving effects on cardiac health and amelioration of BP in the patients with HTN. These effects are through miR-126 and miR-27a modulation and ameliorating mitochondrial ROS production.


Author(s):  
Brandon G Fico ◽  
Taha Ali Alhalimi ◽  
Hirofumi Tanaka

Breath-hold diving evokes a complex cardiovascular response. The degrees of hypertension induced by the diving reflex are substantial and accentuated by the underwater swimming. This condition provides a circulatory challenge to properly buffer and cushion cardiac pulsations. We determined hemodynamic changes during the diving maneuver. A total of 20 healthy young adults were studied. Hemodynamics were measured during exercise on a cycle ergometer, apnea, face immersion in cold water (trigeminal stimulation), and simulated breath-hold diving. Dynamic arterial compliance (measured by changes in carotid artery diameter via ultrasound divided by changes in carotid blood pressure as assessed by arterial tonometry) increased with simulated diving compared with rest (p=0.007) and was elevated compared with exercise and apnea alone (p<0.01). A significant increase in heart rate was observed with exercise, apnea, and facial immersion when compared with rest (p<0.001). However, simulated diving brought the heart rate down to resting levels. Cardiac output increased with all conditions (p<0.001), with an attenuated response during simulated diving compared with exercise and facial immersion (p<0.05). Mean blood pressure was elevated during all conditions (p<0.001), with a further elevation observed during simulated diving compared with exercise (p<0.001), apnea (p=0.016), and facial immersion (p<0.001). Total peripheral resistance was decreased during exercise and facial immersion compared with rest (p<0.001) but was increased during simulated diving compared with exercise (p<0.001), apnea (p=0.008), and facial immersion (p=0.003). We concluded that central artery compliance is augmented during simulated breath-hold diving to help buffer cardiac pulsations.


2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Peter Düking ◽  
Philipp Kunz ◽  
Florian A. Engel ◽  
Helena Mastek ◽  
Billy Sperlich

Abstract Objective Portable gas exchange instruments allow the assessment of peak oxygen uptake (V̇O2peak) but are often bulky, expensive and require wearing a face mask thereby limiting their routine application. A newly developed miniaturized headset (VitaScale, Nuremberg, Germany) may overcome these barriers and allow measuring V̇O2peak without applying a face mask. Here we aimed (i) to disclose the technical setup of a headset incorporating a gas and volume sensor to measure volume flow and expired oxygen concentration and (ii) to assess the concurrent criterion-validity of the headset to measure V̇O2peak in 44 individuals exercising on a stationary cycle ergometer in consideration of the test–retest reliability of the criterion measure. Results The coefficient of variation (CV%) while measuring V̇O2peak during incremental cycling with the headset was 6.8%. The CV% for reliability of the criterion measure was 4.0% for V̇O2peak. Based on the present data, the headset might offer a new technology for V̇O2peak measurement due to its low-cost and mask-free design.


Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 79
Author(s):  
Benjamin J. Narang ◽  
Giorgio Manferdelli ◽  
Katja Kepic ◽  
Alexandros Sotiridis ◽  
Damjan Osredkar ◽  
...  

Pre-term birth is associated with numerous cardio-respiratory sequelae in children. Whether these impairments impact the responses to exercise in normoxia or hypoxia remains to be established. Fourteen prematurely-born (PREM) (Mean ± SD; gestational age 29 ± 2 weeks; age 9.5 ± 0.3 years), and 15 full-term children (CONT) (gestational age 39 ± 1 weeks; age 9.7 ± 0.9 years), underwent incremental exercise tests to exhaustion in normoxia (FiO2 = 20.9%) and normobaric hypoxia (FiO2 = 13.2%) on a cycle ergometer. Cardio-respiratory variables were measured throughout. Peak power output was higher in normoxia than hypoxia (103 ± 17 vs. 77 ± 18 W; p < 0.001), with no difference between CONT and PREM (94 ± 23 vs. 86 ± 19 W; p = 0.154). V̇O2peak was higher in normoxia than hypoxia in CONT (50.8 ± 7.2 vs. 43.8 ± 9.9 mL·kg−1·min−1; p < 0.001) but not in PREM (48.1 ± 7.5 vs. 45.0 ± 6.8 mL·kg−1·min−1; p = 0.137; interaction p = 0.044). Higher peak heart rate (187 ± 11 vs. 180 ± 10 bpm; p = 0.005) and lower stroke volume (72 ± 13 vs. 77 ± 14 mL; p = 0.004) were observed in normoxia versus hypoxia in CONT, with no such differences in PREM (p = 0.218 and > 0.999, respectively). In conclusion, premature birth does not appear to exacerbate the negative effect of hypoxia on exercise capacity in children. Further research is warranted to identify whether prematurity elicits a protective effect, and to clarify the potential underlying mechanisms.


Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 39
Author(s):  
Olga I. Parshukova ◽  
Nina G. Varlamova ◽  
Natalya N. Potolitsyna ◽  
Aleksandra Y. Lyudinina ◽  
Evgeny R. Bojko

The purpose of our study was to identify the features of metabolic regulation in highly trained cross-country skiers of different qualifications at different stages of the maximum load test. We examined 124 highly trained cross-country skiers (male, ages 17–24). The group consisted of two subgroups based on their competition performance: 61 nonelite athletes (Group I) and 63 elite athletes (group II), who were current members of the national team of the Komi Republic and Russia. The bicycle ergometer test was performed by using the OxyconPro system (Erich Jaeger, Hoechberg, Germany). All the examined athletes performed the exercise test on a cycle ergometer “until exhaustion”. The results of our research indicate that the studied groups of athletes with high, but different levels of sports qualifications are a convenient model for studying the molecular mechanisms of adaptation to physical loads of maximum intensity. Athletes of higher qualifications reveal additional adaptive mechanisms of metabolic regulation, which is manifested in the independence of serum lactate indicators under conditions of submaximal and maximum power from maximal oxygen uptake, and they have an NO-dependent mechanism for regulating lactate levels during aerobic exercise, including work at the anaerobic threshold.


2021 ◽  
Vol 11 (24) ◽  
pp. 12048
Author(s):  
Kaori Ochiai ◽  
Yuma Tamura ◽  
Masato Terashima ◽  
Tomoki Tsurumi ◽  
Takanori Yasu

Vigorous exercise increases blood viscosity and may pose a risk of cardiovascular events in patients with cardiovascular diseases. We recently reported that single-use of novel whole-body neuromuscular electrical stimulation (WB-NMES) can be safely applied in healthy subjects without adversely affecting blood fluidity. We performed a crossover study to explore the effectiveness and safety of a hybrid exercise with ergo-bicycle and WB-NMES; 15 healthy volunteers, aged 23–41 years, participated in this study. No arrhythmias were detected during the hybrid exercise and 20 min recovery, and although blood fluidity was transiently exacerbated immediately after both the exercise programs, in vivo parameters in the sublingual and nailfold microcirculation remained unchanged. There was a significant decrease in blood glucose and increase in lactic acid levels immediately after both exercise programs. Even with the same workload as the cycle ergometer exercise, the oxygen intake during the hybrid exercise remained higher than that during the cycle ergometer exercise alone (p < 0.05, r = 0.79, power = 0.81). Both the hybrid and voluntary cycle ergometer exercises transiently exacerbated blood fluidity ex vivo; however, microvascular flow was not adversely affected in vivo.


2021 ◽  
Vol 50 (1) ◽  
pp. 521-521
Author(s):  
Megan Kupferschmid ◽  
Samantha Monk ◽  
Kimberly Burkiewicz ◽  
Maureen Welty ◽  
Jamie Poorman ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document