Cycle Ergometer Exercise Research Articles

Long-term effects of a home exercise program in patients with acute myocardial infarction and percutaneous coronary intervention: prospective observational study

OBJECTIVE: Our aim was to evaluate the effects of home physical training (HPT) in patients with acute myocardial infarction (AMI) and percutaneous coronary intervention (PCI) in 1 year and the long-term period.
 MATERIALS AND METHODS: A prospective observational study was conducted. Ninety-seven patients after AMI and PCI were included: Group 1 (n=51) patients exercising at home for the next year after PCI (HPT+), and Group 2 (n=46) no exercises (HPT). The evaluation was performed at baseline, in 1 year, and 8.90.9 years. The long-term response rate was 42 patients (82.4%) in the HPT+ group and 36 (78.3%) in the HPT- group.
 RESULTS: Patients in the HPT+ group had significantly higher physical performance at the cycle ergometer exercise test in 1 and 8.90.9 years: exercise time increased by 31.4% (p 0.001) and 40% (p 0.001), respectively, and the load increased by 15.6% (p 0.001) and 32.2% (p 0.001), whereas these indicators did not change significantly in HPT- group. Daily physical activity (PA) increased by 21.9% (p 0.01) in 1 year and 19.6% (p 0.01) in 8.90.9 years in the HPT+ group. PA did not change in the HPT- group in 1 year and decreased by 23.1% (p 0.001) in 8.90.9 years to a low level. The left ventricle ejection fraction in the HPT+ group increased by 2.4% (p 0.05) in 1 year and 6.8% (p 0.05) in 8.90.9 years with no changes in HPT- group. Quality of life increased more significantly in the HPT+ group by 50.6% (p 0.05) in 1 year and 71.6% (p 0.01) in 8.90.9 years versus 25.4% (p 0.05) and 46.9% (p 0.05), respectively, in the HPT- group. In the long-term period, the HPT+ group had fewer adverse clinical outcomes, with 22 patients compared with 28 (52.4 vs 77.8%, p 0.05).
 CONCLUSION: Patients with AMI and PCI who participated in a one-year HPT program had positively affected exercise tolerance, myocardial contractility, QoL, and adverse events in the long-term follow-up period.

Feedback control of heart rate during treadmill exercise based on a two-phase response model.

This work investigated automatic control of heart rate during treadmill exercise. The aim was to theoretically derive a generic feedback design strategy that achieves a constant input sensitivity function for linear, time-invariant plant models, and to empirically test whether a compensator C2 based on a second-order model is more dynamic and has better tracking accuracy than a compensator C1 based on a first-order model. Twenty-three healthy participants were tested using first and second order compensators, C1 and C2, respectively, during 35-minute bouts of constant heart rate treadmill running. It was found that compensator C2 was significantly more accurate, i.e. it had 7% lower mean root-mean-square tracking error (1.98 vs. 2.13 beats per minute, p = 0.026), and significantly more dynamic, i.e. it had 17% higher mean average control signal power (23.4 × 10-4 m2/s2 vs. 20.0 × 10-4 m2/s2, p = 0.011), than C1. This improvement likely stems from the substantially and significantly better fidelity of second-order models, compared to first order models, in line with classical descriptions of the different phases of the cardiac response to exercise. These outcomes, achieved using a treadmill, are consistent with previous observations for the cycle ergometer exercise modality. In summary, whenever heart rate tracking accuracy is of primary importance and a more dynamic control signal is acceptable, the use of a compensator based on a second-order nominal model is recommended.

The Effects of Type of Exercise on Ventilatory Efficiency (VE/VCO2) in 11-16-Year-Old Healthy Individuals: A Randomized Clinical Trial

Background: The ventilatory equivalent for CO2 (VE/VCO2 ) is the simplest way to predict ventilatory efficiency. This study aimed to investigate the impact of treadmill and cycle ergometer exercise tests on ventilatory outcomes in healthy adolescents. Methods: In this clinical trial with cross-over design, 52 adolescents aged 11-16 years old (age: 13.8±0.17 years, height: 157.4±0.95 cm, weight: 51.73±1.24 kg, represented as mean±standard error), went through treadmill and cycle ergometer exercise tests with a 6-day wash-out during July-August 2019, Tehran, Iran. Through a RAMP (raise, activate, mobilise, and potentiate) protocol, participants were asked to perform the maximal treadmill or cycle ergometer exercise and continue the test until exhaustion. Gas exchange and heart rate (HR) were obtained breath by breath during the test. Time, HR, VE/VCO2, minute ventilation) VE), end-tidal carbon dioxide pressure (PetCO2), and dead space (VD) to tidal volume (VT) ratios (VD/VT) were transferred to the computer and recorded. All data were reported at two-time points: Anaerobic threshold (AT) V-slop method and peak. Independent t-test was then performed to compare the two types of exercises using SPSS 16, and P˂0.05 was considered significant. Results: The results showed a significant difference in two points regarding the type of exercise for Time and VE/VCO2, but for HR (P=0.004), VE (P=0.0001), PetCO2 (P=0.008), and VD/VT (P=0.004), a significant difference was only observed in AT point. Conclusion: Several physiological mechanisms that occurred during the development stage could affect individuals’ respiratory parameters; however, in general, the type of exercise test affected VE/VCO2.

Comparison of Cardiovascular Response to Lower Body and Whole Body Exercise Among Sedentary Young Adults.

Background Cardiovascular responses to exercise are essential indicators of cardiovascular health and fitness. Understanding how different types of exercise, such as lower-body and whole-body exercises, impact these responses is crucial for designing effective fitness programs and assessing cardiovascular function. Aim This study aimed to compare the cardiovascular response of young adults during lower-body exercise using a bicycle ergometer and whole-body exercise on a treadmill. Methods Thirty-two healthy young adults participated in this study. Each participant completed two exercise sessions on separate days: lower-body exercise on a bicycle ergometer with a fixed cadence of 60 rpm with a breaking resistance of 1.75 kg and whole-body exercise on a treadmill with a speed of 1.7 mph and a 10% grade. Heart rate (HR), systolic blood pressure (BP), and diastolic BP were measured at rest and immediately after a three-minute exercise. Data were analyzed using paired t-tests to compare the cardiovascular responses between the two exercise modalities. Results A total of 17 male and 15 female young adults with a mean age of 20.87±1.43 years participated in the study. The male and female participants had similar ages (p =0.56) and body mass indexes (p = 0.1). There was a higher HR (129.16±2.67 versus 150.87±3.23, p<0.0001) and systolic BP (127.29±2.34 versus 144.9±4.16, p<0.0001) and lower diastolic BP (68.97±2.41 versus 62.97±2.31, p<0.0001) in whole body exercise on treadmill compared to lower body exercise in bicycle ergometer. The effect size was large enough as Cohen's d was 7.33, 5.13, and 2.54 for HR, systolic BP, and diastolic BP, respectively. Conclusion In sedentary young adults, treadmill exercise led to higher HR, systolic BP, and lower diastolic BP than bicycle ergometer exercise. Increased muscle recruitment might result in higher energy expenditure, increasing the HR and systolic BP to deliver oxygen and nutrients to the working muscles. Further research is needed to understand the mechanisms and long-term implications for precise exercise recommendations and better cardiovascular health management.

Effects of Cycle Ergometer Training on Heart Rate Recovery and Mind Fullness in NYHA class I, II Heart Failure Patients

Aim: To determine effect of Cycle ergometer on heart rate recovery and mindfulness in NYHA Class I and II heart failure pts. Study design: The study was a randomized controlled trial. Place and duration: Total study duration was 6 months, carried out at Rawal general and dental hospital Islamabad. Methodology: 38 patients were divided into the Control and experimental group. The control group received only conventional Therapy at home and the hospital on the third and 6th weeks for a supervised conventional therapy session. The experimental group received conventional therapy and cycle ergometer training thrice weekly for six weeks. Baseline demographic data, Vitals, HRR1, HRR2, and MAAS scores were gathered from both groups and compared after six weeks. Results: The mean age of the control group was (46.37±4.43) and of the experimental group (was 50.47±9.22). The MAAS score was significant with a p-value (&lt; 0.05). HRR1 and HRR2 were also significant, with a p-value (&lt;0.05). Conclusion: This study showed that cycle ergometer exercise training significantly improved heart rate recovery in NYHA Class I and II heart failure patients and improved mindfulness. Keywords: Heart failure, Heart Rate Recovery 1(HRR1), Heart Rate Recovery 2 (HRR2), Mindful Attention Aware Scale

A Physiological Anchor for the Perception of Effort.

This is a two-part study to determine one or more reliable physiological anchors for perception of effort. The purpose of Study 1 was to compare ratings of perceived exertion (RPE) at the ventilatory threshold (VT) in running, cycling, and upper body exercise with the premise that if RPE at VT did not differ across exercise modes, VT might provide a unique set of physiological inputs for perception of effort. For 27 participants, values for VT and for RPE at VT (Borg 6 to 20 scale) averaged 9.4km⋅h-1 (SD = 0.7) and 11.9km⋅h-1 (SD = 1.4) respectively in running, 135W (SD = 24) and 12.1W (SD = 1.6) in cycling, and 46W (SD = 5) and 12.0W (SD = 1.7) in upper body exercise. RPE did not differ, suggesting that VT may anchor effort perception. In Study 2, 10 participants performed cycle ergometer exercise for 30 minutes at their VT (M = 101W, SD = 21), at their maximal lactate steady state (M = 143W, SD = 22), and at their critical power (CP; M = 167W, SD = 23). Mean end-exercise RPE were 12.1 (SD = 2.1), 15.0 (SD = 1.9), and 19.0 (SD = 0.5), respectively. The very close clustering of RPE during exercise at CP hints that the confluence of physiological responses at CP may (also) serve as a determinant in perception of effort.

Prognostic value of peak work rate indexed by left ventricular diameter

Left ventricular diameter (LVEDD) increases with systematic endurance training but also in various cardiac diseases. High exercise capacity associates with favorable outcomes. We hypothesized that peak work rate (Wpeak) indexed to LVEDD would carry prognostic information and aimed to evaluate the association between Wpeak/LVEDDrest and cardiovascular mortality. Wpeak/LVEDDrest (W/mm) was calculated in patients with an echocardiographic examination within 3 months of a maximal cycle ergometer exercise test. Low Wpeak/LVEDDrest was defined as a value below the sex- and age-specific 5th percentile among lower-risk subjects. The association with cardiovascular mortality was evaluated using Cox regression. In total, 3083 patients were included (8.0 [5.4–11.1] years of follow-up, 249 (8%) cardiovascular deaths). Wpeak/LVEDDrest (W/mm) was associated with cardiovascular mortality (adjusted hazard ratio (HR) 0.28 [0.22–0.36]), similar to Wpeak in % of predicted, with identical prognostic strength when adjusted for age and sex (C-statistics 0.87 for both). A combination of low Wpeak/LVEDDrest and low Wpeak was associated with a particularly poor prognosis (adjusted HR 6.4 [4.0–10.3]). Wpeak/LVEDDrest was associated with cardiovascular mortality but did not provide incremental prognostic value to Wpeak alone. The combination of a low Wpeak/LVEDDrest and low Wpeak was associated with a particularly poor prognosis.

Pattern of the heart rate performance curve in maximal graded treadmill running from 1100 healthy 18-65 Years old men and women: the 4HAIE study.

Introduction: The heart rate performance curve (HRPC) in maximal incremental cycle ergometer exercise demonstrated three different patterns such as downward, linear or inverse versions. The downward pattern was found to be the most common and therefore termed regular. These patterns were shown to differently influence exercise prescription, but no data are available for running. This study investigated the deflection of the HRPC in maximal graded treadmill tests (GXT) of the 4HAIE study. Methods: Additional to maximal values, the first and second ventilatory thresholds as well as the degree and the direction of the HRPC deflection (kHR) were determined from 1,100 individuals (489 women) GXTs. HRPC deflection was categorized as downward (kHR < -0.1), linear (-0.1 ≤ kHR ≤ 0.1) or inverse (kHR > 0.1) curves. Four (even split) age- and two (median split) performance-groups were used to investigate the effects of age and performance on the distribution of regular (= downward deflection) and non-regular (= linear or inverse course) HR curves for male and female subjects. Results: Men (age: 36.8 ± 11.9 years, BMI: 25.0 ± 3.3 kg m-2, VO2max: 46.4 ± 9.4 mL min-1. kg-1) and women (age: 36.2 ± 11.9 years, BMI: 23.3 ± 3.7 kg m-2, VO2max: 37.4 ± 7.8 mL min-1. kg-1) presented 556/449 (91/92%) downward deflecting, 10/8 (2/2%) linear and 45/32 (7/6%) inverse HRPC´s. Chi-squared analysis revealed a significantly higher number of non-regular HRPC´s in the low-performance group and with increasing age. Binary logistic regression revealed that the odds ratio (OR) to show a non-regular HRPC is significantly affected by maximum performance (OR = 0.840, 95% CI = 0.754-0.936, p = 0.002) and age (OR = 1.042, 95% CI = 1.020-1.064, p < 0.001) but not sex. Discussion: As in cycle ergometer exercise, three different patterns for the HRPC were identified from the maximal graded treadmill exercise with the highest frequency of regular downward deflecting curves. Older subjects and subjects with a lower performance level had a higher probability to show a non-regular linear or inverted curve which needs to be considered for exercise prescription.

Retrospective cohort study at two centers, systolic blood pressure response during exercise testing

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Palacky University Olomouc Faculty of Medicine Czechia. Introduction Measurement of blood pressure (BP) is a standard part of the exercise testing protocol in the general population and in athletes, however, we do not have a sufficient definition of normal and abnormal blood pressure response to exercise and we don´t know the prognostic impact of exercise systolic blood pressure. Purpose To present systolic blood pressure values during exercise in athletes examined by an exercise test. Methods Retrospective analysis of blood pressure response to exercise in a selected cohort of athletes who performed a bicycle ergometer exercise test at two centers. We excluded individuals with prevalent cardiovascular disease. An individual ramp protocol to maximum was used and blood pressure was measured by auscultation method. Resting BP and the highest systolic blood pressure during exercise (SPBmax), maximum heart rate (TF), and maximum workload were recorded for each individual. The SBP/Watt-slope and the SBP/Watt-ratio at peak exercise were calculated. The SBP/Watt-slope was calculated as the ratio of the difference in the rest SPB and peak SPB measurement over the increment of workload. The SBP/Watt-ratio at peak exercise was calculated as the ratio of peak SBD over the peak workload. Sex-specific mean values, standard deviations, and 5th, 25th, 75th and 95th percentiles were determined. Results Between the years 2015 and 2021, 14 702 individuals – 3821 females (27,2 %) and 10 251 males (72,8 %) – underwent the exercise test, with an average age of 19 years (±14). The average Body Mass Index (BMI) was 21,1. The average maximum heart rate achieved was 183/min (±16) and the average peak workload achieved was 3,9 W/kg regardless of gender. The following values were calculated for the whole cohort: peak SBP/Watt-ratio and SBP/Watt-slope. More detailed results are in Table 1. Sex-specific values can be seen in Table 2. Conclusion The values of BP response during exercise testing in our cohort are comparable to recently published data. These data can change the interpretation of SPB response to exercise in the future. There is also a strong need for further research-the multivariate analysis of factors associated with a higher blood pressure response to exercise and determination of sex and age-specific values.

Exercise systolic blood pressure indexed to work rate predicts future risk of incident stroke

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): 1) The CircM network, Linköping University 2) The Swedish Stroke Association. Background Hypertension is a major risk factor for stroke. Exaggerated peak systolic blood pressure (SBP) during exercise is associated with increased risk of hypertension in normotensive subjects, whereas low, rather than high, peak exercise SBP predicts cardiovascular and all-cause mortality. Purpose We aimed to study the risk of incident fatal and non-fatal stroke in relation to absolute and work rate indexed exercise SBP, in patients referred for exercise testing. Methods We cross-linked clinical data from 14,428 bicycle ergometer exercise tests with data from the National Patient Registry and the Registry of Prescribed Medications up until December 2019. Subjects with a history of cerebrovascular disease were excluded, as well as subjects with submaximal tests, a drop in SBP during exercise, or with missing SBP data at the end of exercise. Baseline comorbidity was defined as diagnosis of, or treatment for, hypertension, diabetes, hyperlipidemia, and coronary artery disease (CAD). Work rate indexed SBP response (SBP/Watt-slope) was calculated as the increase in SBP during exercise divided by the increase in work rate. We applied Cox regression to calculate hazard ratios (HR) with 95% confidence intervals (95% CI) for the risk of incident stroke in association to peak SBP and the SBP/Watt-slope. We used absolute values as well the upper limit of normal (≥2 Z scores) of a recently published reference population, with reference equation including age, sex, SBP at rest, Wmax (for SBP peak only) and height (for SBP/W-slope only). Analyses were adjusted for age, sex, and baseline comorbidity. Results In total, 7,946 subjects (54% male, age 55±13 years) were included, with baseline comorbidity of hypertension (28%), diabetes (7%), hyperlipidemia (16%), and CAD (13%). During a median follow-up of 8.4 years (inter quartile range 5.8-11.5), 3.1% developed ischemic (2.2%) or hemorrhagic (1.0%) stroke. There were positive associations to future stroke with absolute peak exercise SBP (HR: 1.08 [1.03 – 1.13] per 10 mmHg increase) and with SBP/Watt-slope (HR: 1.09 [1.05 – 1.14] per 1 mmHg/10 Watt increase), but not after adjustment for sex, age and baseline comorbidity. However, having a SBP/Watt-slope ≥2 Z scores was associated with an increased risk for stroke (HR: 1.56 [1.08 – 2.25)] after adjustment for baseline comorbidity, whereas an adjusted SBP peak ≥2 Z scores was not (HR: 0.62 [0.32 – 1.21]). Conclusion A workload-indexed SBP response (SBP/Watt-slope) above the upper limit of normal may help to identify subjects with no history of cerebrovascular disease at risk of future stroke. In contrast, the absolute exercise SBP response to exercise does not add substantial information to the risk estimation above age, sex, and baseline comorbidity.

Hyperoxia-induced stepwise reduction in blood flow through intrapulmonary, but not intracardiac, shunt during exercise.

Blood flow through intrapulmonary arteriovenous anastomoses (IPAVA) (QIPAVA) increases during exercise breathing air, but it has been proposed that QIPAVA is reduced during exercise while breathing a fraction of inspired oxygen ([Formula: see text]) of 1.00. It has been argued that the reduction in saline contrast bubbles through IPAVA is due to altered in vivo microbubble dynamics with hyperoxia reducing bubble stability, rather than closure of IPAVA. To definitively determine whether breathing hyperoxia decreases saline contrast bubble stability in vivo, the present study included individuals with and without patent foramen ovale (PFO) to determine if hyperoxia also eliminates left heart contrast in people with an intracardiac right-to-left shunt. Thirty-two participants consisted of 16 without a PFO; 8 females, 8 with a PFO; 4 females, and 8 with late-appearing left-sided contrast (4 females) completed five, 4-min bouts of constant-load cycle ergometer exercise (males: 250 W, females: 175 W), breathing an [Formula: see text] = 0.21, 0.40, 0.60, 0.80, and 1.00 in a balanced Latin Squares design. QIPAVA was assessed at rest and 3 min into each exercise bout via transthoracic saline contrast echocardiography and our previously used bubble scoring system. Bubble scores at [Formula: see text]= 0.21, 0.40, and 0.60 were unchanged and significantly greater than at [Formula: see text]= 0.80 and 1.00 in those without a PFO. Participants with a PFO had greater bubble scores at [Formula: see text]= 1.00 than those without a PFO. These data suggest that hyperoxia-induced decreases in QIPAVA during exercise occur when [Formula: see text] ≥ 0.80 and is not a result of altered in vivo microbubble dynamics supporting the idea that hyperoxia closes QIPAVA.

THE INFLUENCE OF DOSED PHYSICAL EXERCISE ON INDICATORS OF THE CARDIOVASCULAR SYSTEM OF PERSONS WHO HAVE LOST LIMBS

The study of the reaction of the cardiovascular system of persons with amputation of the lower limbs at different levels at the initial stage of the application of physical rehabilitation and dosed veloergometric load with the execution of pedal rotation with the upper limbs. Material. In the course of the study, theoretical analysis and generalization of data from the scientific and methodological literature on issues related to the use of physical therapy in people after amputation of the lower limbs, variation pulsometry, determination of maximum oxygen absorption, measurement of blood pressure, dosed veloergometric load with the execution of pedal rotation of the upper limbs were used. Results. The analysis of modern scientific and methodological literature made it possible to consider the actual problem of scientifically based selection of rehabilitation measures to determine the amount of physical exertion for persons at the initial stage (post-hospital period) of the use of physical therapy means, depending on the level of amputation of the lower limbs and the reaction of the cardiovascular system to the performance of dosed cycle ergometric exercise load and control of their influence on hemodynamic indicators. The level of physical working capacity, the reaction of the cardiovascular system and the level of physical working capacity of persons with amputation of the lower limbs at different levels by means of dosed veloergometric load with the use of the upper limbs at the initial stage (post-hospital period) were studied, which are decisive in the individual appointment of the movement regime, the formation of the volume and intensity of physical exertion, selection of appropriate forms, methods and means of physical therapy. Conclusions. The applied adequate research methods made it possible to reveal the dependence of the reaction of the indicators of heart rate, blood pressure and maximum oxygen absorption on the amount of dosed veloergometric load depending on the localization, volume and level of amputation of the lower limbs, which will allow the application of a motor mode adequate to the functional state, the intensity of physical exercises, forms, methods and means of physical therapy for persons with different levels of amputation of the lower limbs.

Heart Rate Responses at Rest, during Exercise and after Exercise Periods in Relation to Adiposity Levels among Young Nigerian Adults.

There is a dearth of comparative studies on heart rate (HR) abnormalities at rest, chronotropic responses during submaximal exercise, and such responses during recovery from submaximal exercise between healthy-weight and overweight/obese young adults. Eighty healthy young adults (30 men and 50 women) aged 19 to 33 years participated in the present study. A symptom-limited, submaximal, cycle ergometer exercise test of intensity targeted at 60% to 70% of the subject's age-predicted maximum HR was performed. The HR, blood pressure, and minute ventilation were measured at rest and during exercise. Post-exercise, HR was first measured at 1 minute of recovery and then every 2 minutes until the 5th minute. Our results showed significantly higher resting HR (P<0.001), lower percentage HR reserve during exercise (P<0.001), and slower HR recovery after exercise (P<0.05, P<0.01, or P<0.001) in overweight/obese men and women than in the non-overweight/obese controls. The prevalence of high resting HR, submaximal chronotropic incompetence, and blunted HR recovery were more common in the overweight/obese individuals than in the healthy-weight controls. Peak VO2 and ventilatory equivalent for oxygen were associated with resting HR, exercise HR parameters, and post-exercise HR recovery indices in both men and women. High resting HR, submaximal chronotropic incompetence, and blunted HR recovery in overweight/obese individuals in this study may be attributed to poor cardiorespiratory fitness and low respiratory efficiency.

The influence of exercise volume and posture on exercise-induced plasma volume expansion.

Acute high-intensity interval exercise is known to expand plasma volume 24 h after exercise. Upright exercise posture plays a role in expanding plasma volume by influencing lymphatic outflow and redistributing albumin while supine exercise does not. We examined if further upright and weight-bearing exercises could further promote plasma volume expansion. We also tested the volume of intervals needed to induce plasma volume expansion. To test the first hypothesis, 10 subjects performed intermittent high-intensity exercise (4min at 85% V̇O2max , 5min at 40% V̇O2max repeated 8 times) on separate days on the treadmill and cycle ergometer. For the second study, 10 subjects performed four, six, and eight intervals of the same interval protocol on separate days. Changes in plasma volume were calculated from changes in hematocrit and hemoglobin. Transthoracic impedance (Z0 ) and plasma albumin were assessed while seated before and postexercise. Plasma volume increased 7.3% ± 4.4% and 6.3% ± 3.5% following treadmill and cycle ergometer exercise, respectively. For four, six, and eight intervals, plasma volume increased by 6.6% ± 4.0%, 4.7% ± 2.6%, and 4.2% ± 5.6%, respectively. The increases in plasma volume were similar for both exercise modes and all three exercise volumes. There were no differences in Z0 or plasma albumin content between trials. In conclusion, rapid plasma volume expansion following eight bouts of high-intensity intervals appears to be independent of upright exercise posture (treadmill versus cycle ergometer). Meanwhile, plasma volume expansion was similar after four, six, and eight intervals of cycle ergometry.

Caffeine Augments the Lactate and Interleukin-6 Response to Moderate-Intensity Exercise.

The release of interleukin (IL)-6 from contracting skeletal muscle is thought to contribute to some of the health benefits bestowed by exercise. This IL-6 response seems proportional to exercise volume and to lactate production. Unfortunately, high volumes of exercise are not feasible for all people. Caffeine augments the magnitude of increase in circulating IL-6 in response to high-intensity and long-duration exercise. Caffeine also increases circulating concentrations of lactate during exercise. We hypothesized that caffeine, ingested before short-duration, moderate-intensity exercise, would lead to greater circulating concentrations of lactate and IL-6 in a study population comprising both male and female individuals. Twenty healthy adults (10 men and 10 women age 25 ± 7 yr (mean ± SD)) completed 30 min of moderate-intensity cycle ergometer exercise, at an intensity corresponding to 60% peak oxygen uptake, after ingesting either caffeine (6 mg·kg -1 ) or placebo. Arterialized-venous blood was collected throughout each of the exercise sessions. Compared with placebo, caffeine increased circulating concentrations of lactate at the end of exercise (5.12 ± 3.67 vs 6.45 ± 4.40 mmol·L -1 , P < 0.001) and after 30 min of inactive recovery (1.83 ± 1.59 vs 2.32 ± 2.09 mmol·L -1 , P = 0.006). Circulating IL-6 concentrations were greatest after 30 min of inactive recovery ( P < 0.001) and higher with caffeine (2.88 ± 2.05 vs 4.18 ± 2.97, pg·mL -1 , P < 0.001). Secondary analysis indicated sex differences; caffeine increased the IL-6 response to exercise in men ( P = 0.035) but not in women ( P = 0.358). In response to moderate-intensity exercise, caffeine evoked greater circulating lactate concentrations in men and women but only increased the IL-6 response to exercise in men. These novel findings suggest that for men unwilling or unable to perform high-intensity and/or long-duration exercise, caffeine may augment the health benefits of relatively short, moderate-intensity exercise.

Quantification of Physical Activities Simulated Exercise Therapy in Ambulatory Inpatients Using Surface Electromyogram from the Vastus Medialis

The present study aimed to assess whether surface electromyogram (sEMG) signal from the vastus medialis could be a candidate method to quantify physical activities during combined activities in ambulatory persons (ergometer exercise, treadmill walking, and squatting). In the first trial, eleven healthy men performed a graded cycle ergometer exercise at 0%, 30%, 60%, and 80% of peak oxygen consumption rate (VO2peak), followed by treadmill walking at 0, 2, 4, and 6 km/h for 3 min of each, and each exercise was intermitted by 3 min of rest. sEMG from the Vastus Medialis Oblique Longus (VML) was collected, and the integrated amplitude of spikes (sEMGAMP) were calculated every minute. Positive correlations were observed between ΔVO2 and ΣsEMGAMP; data at sampling frequency of 250Hz in both exercise types were plotted (r=0.888; P<0.0001; y=339.04x+4.0267). In the second trial, thirteen healthy participants (three women) performed the combined exercise comprising 3 min each for optimal walking (3 km/h), fast walking (5 km/h and 6 km/h for women and men, respectively), squatting, second optimal walking, and ergometer exercise at 30% VO2peak, which were intermitted by 30 sec. Finally, they performed ergometer exercise at 100% VO2peak for 1 min followed by 3-min cool-down (0W). Changes (Δ) in VO2 from the resting value and sEMGAMP during exercise were summed throughout the exercise period (ΣΔVO2 and ΣsEMGAMP). ΣΔsEMGAMP was positively correlated with ΣΔVO2 (r=0.68, p=0.011, @250Hz). Monitoring sEMG from VML may be a candidate method for the evaluation of physical activities for exercise therapy in ambulatory persons.

Multiple Sessions of One-Legged Recumbent Cycle Ergometer Exercise Improved Pedaling Rate and Knee Range of Motion in a Middle-Aged Man after Hip Disarticulation: A Clinical Case

Background: This case evaluates the short-term training effects with alterations in pedaling rate (PR) and its relationship to knee range of motion (KROM) after multiple sessions of one-legged recumbent cycle ergometer exercise (1LREx) in a patient after hip disarticulation (HD). Case: A 44-year-old male patient had left HD due to osteosarcoma. He performed unilateral right 1LREx at 10 W with a self-controlled freely chosen PR until exhaustion. Multiple 1LREx sessions (maximum 4-5 sessions/day) were performed over 6 consecutive days from day 15 post-HD. PR and right KROM in the downstroke (pushing) and upstroke (pulling) pedal phases were determined continuously using a goniometer placed between the thigh and lower leg. The PR time-course during 1LREx indicated differences among multiple daily sessions but tended to be higher and more stable at steady-state over the study period (average ± SD PR and its coefficients of variability, 33.2 ± 5.3 revolution per minute (rpm) and 28.0% on Day 1 versus 43.0 ± 3.0 rpm and 12.5% on Day 6). The time-course of KROM was similar among multiple sessions during each day; however, the average KROM over all sessions in a day tended to increase over the study period (51.0 ± 1.2° on Day 1 vs. 78.0 ± 2.3° on Day 6). Mean KROM in the downstroke or upstroke pedal phases during each session showed a significant positive linear correlation (total of 27 sessions, p &lt; 0.05) with mean PR. Conclusion: After HD, short-term one-legged trainability with multiple 1LREx resulted in increased KROM and PR with uniformly faster PR with whole leg exercising in the sagittal plane

Edible marijuana and cycle ergometer exercise.

Purpose: There is extensive public and scientific interest in the influence of cannabis and the psychoactive cannabinoid, delta-9-tetrahydrocannabinol (THC), on exercise performance. Unfortunately, recent, up-to-date studies are lacking. The aim of the current study was to address the hypothesis that ingestion of edible marijuana, prior to exercise, would have unfavorable effects on the physiological response to exercise and on exercise performance. Methods: 17 Healthy adult male and female habitual exercisers, who were regular users of cannabis products, were screened for study participation. 10 were enrolled, and data from 9 [8 males, 1 female, aged 25±3years, with peak oxygen uptake of 56.5±11.7ml/kg/min (mean ± SD)] were retained. Participation included two exercise sessions, each preceded by self-administration and ingestion of either edible marijuana (containing 10mg THC) or placebo. Cardio-respiratory responses (via indirect calorimetry) to stationary cycle ergometer exercise (8min at 50, 100 and 150 W) were recorded before completion of a 20-min Functional Threshold Power test (FTP20) and a sprint test involving maximal effort until volitional fatigue. Results: Edible marijuana increased the concentration of circulating THC and THC metabolites, and evoked sensations of intoxication and altered psychoactive state. Cardio-respiratory responses to staged cycle ergometer exercise were normal and were unaffected by edible marijuana. Compared with placebo, edible marijuana did not influence FTP20 (Placebo 253±75 vs THC: 251±72W (mean±SD); p > 0.45) or peak power output during the sprint test (Placebo: 710±201 vs. THC: 732±136W; p = 0.864). Conclusion: 10mg of THC, when ingested prior to exercise by regular exercisers and habitual users of cannabis, had little effect on the physiological response to standardized cycle ergometer exercise, and was neither ergogenic nor ergolytic.

Glucose and Fructose Supplementation and Their Acute Effects on Anaerobic Endurance and Resistance Exercise Performance in Healthy Individuals: A Double-Blind Randomized Placebo-Controlled Crossover Trial.

The effects of glucose, fructose and a combination of these on physical performance have been subject of investigation, resulting in diverse findings. The aim of this study was to investigate how an individualized amount of glucose, fructose, and a combination of these compared to placebo (sucralose) alter endurance performance on a cycle ergometer, lower and upper body resistance exercise performance at individualized thresholds in healthy young individuals. A total of 16 healthy adults (9 females) with an age of 23.8 ± 1.6 years and a BMI of 22.6 ± 1.8 kg/m2 (body mass (BM) 70.9 ± 10.8 kg, height 1.76 ± 0.08 m) participated in this study. During the screening visit, the lactate turn point 2 (LTP2) was defined and the weights for chest-press and leg-press were determined. Furthermore, 30 min prior to each exercise session, participants received either 1 g/kg BM of glucose (Glu), 1 g/kg BM of fructose (Fru), 0.5 g/kg BM of glucose/fructose (GluFru) (each), or 0.2 g sucralose (placebo), respectively, which were dissolved in 300 mL of water. All exercises were performed until volitional exhaustion. Time until exhaustion (TTE) and cardio-pulmonary variables were determined for all cycling visits; during resistance exercise, repetitions until muscular failure were counted and time was measured. During all visits, capillary blood glucose and blood lactate concentrations as well as venous insulin levels were measured. TTE in cycling was 449 ± 163 s (s) (Glu), 443 ± 156 s (Fru), 429 ± 160 s (GluFru) and 466 ± 162 s (Pla) (p = 0.48). TTE during chest-press sessions was 180 ± 95 s (Glu), 180 ± 92 s (Fru), 172 ± 78 s (GluFru) and 162 ± 66 s (Pla) (p = 0.25), respectively. Pre-exercise supplementation of Glu, Fru and a combination of these did not have an ergogenic effect on high-intensity anaerobic endurance performance and on upper and lower body moderate resistance exercise in comparison to placebo.

Impact of Exercise Training at Different Intensity Levels on Cardiac Function and Exercise Capacity in Patients with Chronic Heart Failure: A Prospective Cohort Study.

To investigate training at different intensity levels on cardiac function, exercise capacity, and health-related quality of life in patients with chronic heart failure. This prospective cohort study enrolled patients with chronic heart failure at Beijing Rehabilitation Hospital, Beijing, China from January 2018 to January 2020. Participants received conventional therapy (non-exercise group) or therapy plus cycle ergometer exercises at an intensity of 80% anaerobic threshold (EA group) and Δ50% power above anaerobic threshold (EB group) for 12 weeks. The primary outcome was peak oxygen uptake. Forty-five patients (15/group) completed the study without serious complications. Exercise training at an intensity of Δ50% power above anaerobic threshold had better effects on exercise capacity than exercise at an intensity of 80% anaerobic threshold, as shown by a greater improvement in peak oxygen uptake (20.3 ± 4.1 vs 16.8 ± 3.2 mL/min/kg), peak O2 pulse (12.5 ± 2.3 vs 10.1 ± 2.1 mL/beat), and peak workload (123.1 ± 26.9 vs 102.8 ± 29.5 W) in patients with chronic heart failure (all p < 0.001). Exercise improved the 6-min walk test distance (control: 394.0 ± 74.1; EA: 481.4 ± 89.4; EB: 508.9 ± 92.5 m; p < 0.001) and health-related quality of life (control: 40.7 ± 12.3; EA: 16.2 ± 8.6; EB: 11.5 ± 6.4; p < 0.001). Compared with an intensity of 80% anaerobic threshold, exercise training at an intensity of Δ 50% power above anaerobic threshold was safe and had better effects on cardiac function, exercise capacity, and health-related quality of life.