Comparison of Peak Aerobic Capacity Between the Treadmill and a Skiing Ergometer

Introduction: The Concept2 SkiErg is increasing in popularity and is widely used to provide a low impact total body workout. Because of these benefits, the SkiErg could be an ideal tool for fitness testing. Therefore, the purpose of this study was to compare VO2peak values elicited from a treadmill (TM) and SkiErg (SE) graded exercise test (GXT). Methods: Twenty-two averagely fit females completed 2 GXT protocols to volitional exhaustion on a TM and SE. Peak VO2, HR, VE, TTE, and RER were compared using paired-samples t-tests with significant differences at p≤0.05. Max RPE was compared using a Wilcoxon Signed Rank Test. Results: TM was significantly greater than SE for VO2peak (43.82±1.07 vs 33.97±5.01 ml/kg/min, p<0.01), HR (189±8 vs 182±11 bpm, p<0.01), RPE (18.91+1.11vs 17.26+2.03, p=0.02), VE (95.44±11.26 vs 86.21±2.90 L/min, p=0.015), and TTE (550.16+137.56 vs 391.86±81.20 sec, p<0.01). RER was significantly greater on the SE (1.16±0.08 vs 1.12±0.06, p=0.024). Conclusion: Results suggest that TM elicits higher max values for VO2, HR, TTE, VE, and RPE compared to SE, while SE elicits a higher RER in the current population. SE could be used as an alternative mode of testing in averagely-fit females but does not directly compare to TM values.

Cardiac baroreflex dysfunction in patients with pulmonary arterial hypertension at rest and during orthostatic stress: Role of the peripheral chemoreflex

The baroreflex integrity in early-stage pulmonary arterial hypertension (PAH) remains uninvestigated. A potential baroreflex impairment could be functionally relevant and possibly mediated by enhanced peripheral chemoreflex activity. Thus, we investigated 1) the cardiac baroreflex in non-hypoxemic PAH; 2) the association between baroreflex indexes and peak aerobic capacity (i.e., V̇O2peak); and 3) the peripheral chemoreflex contribution to the cardiac baroreflex. Nineteen patients and 13 age- and sex-matched healthy adults (HA) randomly inhaled either 100% O2 (peripheral chemoreceptors inhibition) or 21% O2 (control session), while at rest and during a repeated sit-to-stand maneuver. Beat-by-beat analysis of R-R intervals and systolic blood pressure provided indexes of cardiac baroreflex sensitivity (cBRS) and effectiveness (cBEI). The PAH group had lower cBEIALL at rest (mean ± SD: PAH = 0.5 ± 0.2 vs HA = 0.7 ± 0.1 a.u., P = 0.02) and lower cBRSALL (PAH = 6.8 ± 7.0 vs HA = 9.7 ± 5.0 ms mmHg-1, P < 0.01) and cBEIALL (PAH = 0.4 ± 0.2 vs HA= 0.6 ± 0.1 a.u., P < 0.01) during the sit-to-stand maneuver versus the HA group. The cBEI during the sit-to-stand maneuver was independently correlated to V̇O2peak (partial r = 0.45, P < 0.01). Hyperoxia increased cBRS and cBEI similarly in both groups at rest and during the sit-to-stand maneuver. Therefore, cardiac baroreflex dysfunction was observed under spontaneous and, most notably, provoked blood pressure fluctuations in non-hypoxemic PAH, was not influenced by the peripheral chemoreflex, and was associated with lower V̇O2peak suggesting it could be functionally relevant.

The correlation between quadriceps muscle strength and endurance and exercise performance in patients with COPD

Purpose To determine the association between quadriceps muscle strength (QMS) and endurance (QME) and exercise capacity in COPD patients after stratification for sex and resting lung function (LF). Methods Data were collected in 3246 COPD patients (60% men, 64±9 years), including measures of exercise capacity (peak aerobic capacity (peakVO2)), six-minute walk distance (6MWD)) and isokinetic QMS and QME. Patients were stratified for sex, forced expiratory volume in 1 s (>50/≤50% predicted), single breath carbon monoxide diffusing capacity (>50/≤50% predicted) and residual volume (>140/≤140% predicted). Results After stratification for resting LF, QMS and QME were significantly associated with peakVO2 (r range: 0.47-0.61 and 0.49-0.65 for men; and 0.53-0.66 and 0.48-0.67 for women, respectively)and 6MWD (r range: 0.29-0.42 and 0.44-0.55 for men; and 0.25-0.54 and 0.34-0.55 for women, respectively) (p<0.001). Regression models demonstrated that QMS and QME were significant determinants of peakVO2 (explained variance R2 range: 35.6-48.8% for men; and 36.8-49.0% for women) and 6MWD (R2 range: 24.3-43.3% for men; and 28.4-40.3% for women), independent of age and fat-free mass. Conclusion Quadriceps muscle function was significantly associated with peakVO2 and 6MWD in male and female COPD patients after stratification for resting LF, in which QME appear to be a more important determinant than QMS. This underlines the importance of systematically evaluating both quadriceps muscle strength and endurance in in all COPD patients.

Observations of Performance and Body Composition Following 8-weeks of Progressive Resistance Training in Participants With Cerebral Palsy

Purpose: To observe the effects of progressive resistance training on performance and body composition in participants with cerebral palsy. Methods: Four quadriplegic (3 male, 1 female) and two hemiplegic (2 female) participants (22 ± 5 yr, mean ± SD) completed moderate to high intensity resistance training 2-3 days a week for 8-weeks. Strength training programs were developed for each participant based on their physical ability. Measurements of exercise performance and body composition (InBody 270 & S10) were collected prior to and following training. Data from all participants was pooled, and samples with 5-6 subjects were analyzed using a paired t-test with significance set at p < 0.05. Results: Measurements of muscular fitness improved, including plank performance (pre: 64 ± 40, post: 95 ± 61 s, n = 6), supine sled leg press 1RM (pre: 225 ± 69, post: 378 ± 124 lb, n = 6) and bench/sled press 1RM (pre: 92 ± 54, post: 115 ± 58 lb, n = 5). There was no change in peak sprint capacity (pre: 89 ± 32, post: 96 ± 29 W, n = 5) or peak aerobic capacity (pre: 303 ± 136, post: 370 ± 246 s, n = 4). Measurements of body weight (pre: 151 ± 40, post: 151 ± 42 lb, n = 6) and skeletal muscle mass (pre: 53 ± 8, post: 54 ± 9 lb, n = 6) were unchanged following training. Conclusion: Preliminary data is encouraging that the unique and challenging strength training program employed with these participants can be utilized to gain meaningful improvements in muscular fitness. However, a larger sample size and longer training period may be necessary to significantly increase muscle mass.

Abstract 15911: Is There a Relationship Between Sports Participation and Peak Aerobic Capacity in Children With Congenital Heart Disease?

Introduction: Underlying structural lesions in congenital heart disease (CHD) result in differences in anatomy and physiology that may affect peak aerobic capacity (VO 2peak ). The relationship between sports participation and VO 2peak is unclear in these patients. The aim of this study was to determine if children with CHD who participated in sports had a higher VO 2peak than those who did not. Methods: Two-year, single-centre, retrospective review (May 2016-November 2018). Fifty-eight CHD patients were included: 9 aortic valve disease; 13 coarctation; 6 Ross procedure for aortic stenosis; 20 tetralogy of Fallot, and 10 transposition of the great arteries. Sports participation was categorized into 3 groups: 0-1 days/week; 2-3 days/week; and ≥4 days/week. A validated institutional treadmill protocol (BCCH) was used. Criteria for a maximal test included: VO 2 plateau, respiratory exchange ratio>1.0, and/or a peak heart rate >200 bpm. VO 2peak z-scores, % VO 2 at ventilatory threshold, and O 2 Pulse were calculated. Medians and interquartile ranges are reported. P<0.05 was considered statistically significant. Results: Those who participated in sports ≥2-3 days/week had a significantly higher VO 2peak [39.9 (34.6, 48.1) vs 30.3 (27.8, 39.6) mL/min/kg; p<0.001], VO 2peak z-score [-0.84 (-1.28,-0.30) vs -1.89 (-2.37, -1.16); p=0.002], and O 2 Pulse [0.20 (0.19, 0.25) vs 0.16 (0.14, 0.21) mL/beat/kg; p=0.004] compared to those who participated 0-1 day/week, respectively. There were no differences between those who participated in sports 2-3 days/week and ≥4 days/week. VO 2peak was similar between CHD lesions (p=0.21). Conclusions: VO 2peak is higher in those who participate in sports compared to those who do not. It is unclear whether those who have a higher VO 2peak are more inclined to participate in sports or whether sports participation leads to a higher VO 2peak . The role of exercise rehabilitation in the 0-1 day/week group needs to be explored.

Type 2 diabetes is an independent predictor of lowered peak aerobic capacity in heart failure patients with non-reduced or reduced left ventricular ejection fraction

Background Although type 2 diabetes mellitus (T2DM) is one of the most frequent comorbidities in patients with chronic heart failure (CHF), the effects of T2DM on the exercise capacity of CHF patients are fully unknown. Here, we tested the hypothesis that the coexistence of T2DM lowers CHF patients’ peak aerobic capacity. Methods We retrospectively analyzed the cases of 275 Japanese CHF patients with non-reduced ejection fraction (left ventricular ejection fraction [LVEF] ≥ 40%) or reduced EF (LVEF < 40%) who underwent cardiopulmonary exercise testing. We divided them into diabetic and nondiabetic groups in each CHF cohort. Results The mean peak oxygen uptake (VO2) value was 16.87 mL/kg/min in the non-reduced LVEF cohort and 15.52 mL/kg/min in the reduced LVEF cohort. The peak VO2 was lower in the diabetics versus the nondiabetics in the non-reduced LVEF cohort with the mean difference (95% confidence interval [95% CI]) of − 0.93 (− 1.82 to − 0.04) mL/kg/min and in the reduced LVEF cohort with the mean difference of − 1.05 (− 1.96 to − 0.15) mL/kg/min, after adjustment for age-squared, gender, anemia, renal function, LVEF, and log B-type natriuretic peptide (BNP). The adjusted VO2 at anaerobic threshold (AT), a submaximal aerobic capacity, was also decreased in the diabetic patients with both non-reduced and reduced LVEFs. Intriguingly, the diabetic patients had a lower adjusted peak O2 pulse than the nondiabetic patients in the reduced LVEF cohort, but not in the non-reduced LVEF cohort. A multivariate analysis showed that the presence of T2DM was an independent predictor of lowered peak VO2 in CHF patients with non-reduced LVEF and those with reduced LVEF. Conclusions T2DM was associated with lowered peak VO2 in CHF patients with non-reduced or reduced LVEF. The presence of T2DM has a negative impact on CHF patients’ exercise capacity, and the degree of impact is partly dependent on their LV systolic function.

Multiple Sclerosis: Treadmill Versus Cycle Ergometry Maximal Exercise Test Responses

ABSTRACT Background: Multiple sclerosis (MS) is an autoimmune disease that impacts the central nervous system. MS generally results in decreased mobility and work capacity. Our objective was to determine exercise testing responses on both a treadmill and cycle ergometer among individuals with MS who were able to ambulate freely. Methods: Twenty-six individuals with MS participated in a cross-sectional study (44 ± 11 years; body mass index 26.8 ± 6.2 kg·m−2; expanded disability scale score 3.1 ± 0.9), with 24 individuals with complete test data for both treadmill and cycle ergometry tests. Peak aerobic capacity (VO2peak) for both treadmill and cycle ergometry tests were measured with indirect calorimetry. Results: Participants safely completed both treadmill and cycle ergometry tests, and treadmill testing yielded higher values (26.7 ± 6.4 mL·kg−1·min−1) compared with cycle ergometry (23.7 ± 5.7 mL·kg−1·min−1), with values ~12% greater for treadmill. When comparing tests to their respected predicted values within modality, treadmill tests were 8% lower and cycle ergometry tests were 10% lower than predicted. Conclusions: While peak aerobic capacity was very low for this population, treadmill tests were still higher than cycle ergometry data, with this difference between modes being similar to that observed in healthy adult populations. Additional research is required to determine if these findings are impacted by participation in physical activity or regular exercise.

A Comparison of Two Commercial Swim Bench Ergometers in Determining Maximal Aerobic Power and Correlation to a Paddle Test in a Recreational Surfing Cohort

The recent addition of surfing to the Tokyo 2020 Olympic Games has fueled a surge in commercial and research interest in understanding the physiological demands of the sport. However, studies specific to maximal aerobic testing of surfers are scarce. Therefore, the primary aim of this study was to compare two commercially available swim bench (SWB) ergometers in the determination of maximal aerobic capacity in recreational surfers. A secondary aim was to correlate (independent of one another) the two ergometer findings of VO2peak to the time taken to complete a water-based 400-m paddle test. This cross-sectional study consisted of 17 recreational surfers aged between 18–58 years. Participants were randomized to either the SwimFast ergometer or VASA ergometer and tested for maximal aerobic capacity, followed by a 400-m paddle test. There were no significant differences between the two SWB ergometers in the determination of relative VO2peak (mean difference 0.33 mL/kg/min; 95% CI −1.24–1.90; p = 0.66). Correlations between VO2peak obtained from maximal paddling effort on the SwimFast and the VASA and the 400-m paddle test (total time (s)) showed a negative significant correlation r = −0.819, p = 0.024; r = −0.818, p = 0.024, respectively. Results suggest that either ergometer (SwimFast or VASA) can be used to determine peak aerobic capacity within a recreational surfing cohort. The significant correlation of the two SWB ergometers and the 400-m paddle test suggest that the 400-m paddle test may be a suitable field-based method of determining aerobic capability. Collectively, these preliminary findings provide initial evidence for similarities in VO2peak on two commercial ergometers and their correlations with a field-based test. However, further research is needed with a larger sample size and inclusive of competitive surfers to provide robust findings which can be generalized to the surfing population.