Different ventilatory responses to progressive maximal exercise test performed with either the arms or legs

The effect of age and sex on peak oxygen uptake during upper and lower body exercise: A systematic review

BACKGROUND

Large scale population norms for peak oxygen uptake (VO2peak) during cycle ergometry (CE) have been published for men and women across a wide range of ages. Although upper body functional capacity has an important role in activities of daily living far less is known regarding the effect of age and sex on upper body functional capacity (i.e. arm crank ergometry; ACE). The aim of this review was to determine the effect of age and sex on VO2peak obtained during ACE and CE in the same participants.

METHOD

The review was pre-registered with PROSEPERO (Ref: CRD42022349566). A database search using Academic Search Complete including CINAHL complete, CINHAL Ultimate, Medline, PubMed, SPORTDiscus was undertaken.

RESULTS

The initial search yielded 460 articles which was reduced to 243 articles following removal of duplicates. Twenty-five articles were subsequently excluded based on title resulting in 218 articles considered for retrieval. Following review of the abstracts, 78 further articles were excluded leaving 140 to be assessed for eligibility. Eighty-five articles were subsequently excluded, resulting in 55 articles being included. The decrease in VO2peak with age during CE was consistent with previous studies. Decreases in VO2peak during ACE with age, although paralleling those of CE, appeared to be of greater functional importance. When changes in VO2peak were considered below the age of 50 years little change was observed for absolute VO2peak during ACE and CE. In contrast, relative VO2peak demonstrated decreases in VO2peak for both ACE and CE likely reflecting increases in body mass and body fat percentage with age. After 50 years of age absolute and relative VO2peak demonstrated more similar and subtle responses. Heterogeneity across studies for both absolute and relative VO2peak between ACE and CE was large. Although strict inclusion criteria were applied, the inter-individual variation in sample populations was likely the main source of heterogeneity. There was a considerable lack data sets available for ages above 40 years of age.

CONCLUSIONS

These responses suggest that upper body VO2peak decreases in line with that of the lower body but, due to the lower peak values achieved during ACE, decreases in VO2peak may have more profound functional impact compared to that for the lower body. Using absolute and relative measures of VO2peak results in different age-related profiles when considered below 50 years of age. To further our understanding of whole body ageing more data is required for participants in mid and later life. The association between VO2peak and underlying physiological factors with age needs to be studied further, particularly in conjunction with activities of daily living and independent living.

A Reappraisal of Ventilatory Thresholds in Wheelchair Athletes With a Spinal Cord Injury: Do They Really Exist?

The ventilatory threshold (VT) separates low- from moderate-intensity exercise, the respiratory compensation point (RCP) moderate- from high-intensity exercise. Both concepts assume breakpoints in respiratory data. However, the objective determination of the VT and RCP using breakpoint models during upper-body modality exercise in wheelchair athletes with spinal cord injury (SCI) has received little attention. Therefore, the aim of this study was to compare the fit of breakpoint models (i.e., two linear regression lines) with continuous no-breakpoint models (i.e., exponential curve/second-order polynomial) to respiratory data obtained during a graded wheelchair exercise test to exhaustion. These fits were compared employing adjusted R², and blocked bootstrapping was used to derive estimates of a median and 95% confidence intervals (CI). V̇O₂-V̇CO₂ and V̇E/V̇O₂-time data were assessed for the determination of the VT, and V̇CO₂-V̇E and V̇E/V̇CO₂-time data for the determination of the RCP. Data of 9 wheelchair athletes with tetraplegia and 8 with paraplegia were evaluated. On an overall group-level, there was an overlap in the adjusted R² median ± 95% CI between the breakpoint and the no-breakpoint models for determining the VT (V̇O₂-V̇CO₂: 0.991 ± 0.003 vs. 0.990 ± 0.003; V̇E/V̇O₂-time: 0.792 ± 0.101 vs. 0.782 ± 0.104, respectively) and RCP (V̇E-V̇CO₂: 0.984 ± 0.004 vs. 0.984 ± 0.004; V̇E/V̇CO₂-time: 0.729 ± 0.064 vs. 0.691 ± 0.063, respectively), indicating similar model fit. We offer two lines of reasoning: (1) breakpoints in these respiratory data exist but are too subtle to result in a significant difference in adjusted R² between the investigated breakpoint and no-breakpoint models; (2) breakpoints do not exist, as has been argued previously.

Lifestyle interventions reduce exercise ventilatory variability in healthy individuals: a randomized intervention study

Aim: Variation of exercise ventilation confers poor prognosis in heart failure. Sedentary men have higher exercise ventilatory variability than athletes. However, the impact of lifestyle intervention on exercise ventilatory variability in sedentary people is unknown and this is the aim of this study. Materials & methods: Prospective controlled single-blinded interventional study that randomly assigned healthy sedentary individuals to diet and exercise (intervention group, n = 12) or no intervention (control group, n = 12) for 12 weeks. Exercise ventilatory variability was accessed before and after intervention. Results: Despite similar values at baseline, there was a 15% reduction in respiratory rate variability (root mean square of the successive differences/n) in intervention group. Conclusion: Diet and exercise training reduced exercise ventilatory variability.

A SYSTEMATIC REVIEW AND META-ANALYSIS COMPARING CARDIOPULMONARY EXERCISE TEST VALUES OBTAINED FROM THE ARM CYCLE AND THE LEG CYCLE RESPECTIVELY IN HEALTHY ADULTS

INTRODUCTION

The cardiopulmonary exercise test (CPET) assesses maximal oxygen uptake (VO_2max) and is commonly performed on a leg cycle ergometer (LC). However, some individuals would rather perform the CPET on an arm cycle ergometer (AC).

OBJECTIVE

The objectives of this study were to undertake a systematic review and meta-analysis of the difference in VO_2max achieved by AC compared to LC in healthy adults and to explore factors that may be predictive of this difference.

METHODS

MEDLINE, EMBASE, CINAHL, and PEDro were searched in April 2015. The differences in VO_2max (ACLC_diff) were pooled across studies using random effects meta-analysis and three different methods were used to estimate the ratio between the values obtained from the tests (ACLC_ratio).

RESULTS

This paper included 41 studies with a total of 581 participants. The mean ACLC_diff across studies was 12.5 ml/kg/min and 0.89 l/min with a mean ACLC_ratio of 0.70. The ACLC_diff was lower in studies with higher mean age and lower aerobic capacity.

CONCLUSION

There is linear association between the AC and LC values in healthy adults. The AC values were on average 70% of the LC values. The magnitude of this difference appeared to be reduced in studies on older and less active populations.

LEVEL OF EVIDENCE

3a.

Robotically assisted treadmill exercise training for improving peak fitness in chronic motor incomplete spinal cord injury: A randomized controlled trial

OBJECTIVE

To assess the effectiveness of robotically assisted body weight supported treadmill training (RABWSTT) for improving cardiovascular fitness in chronic motor incomplete spinal cord injury (CMISCI).

DESIGN

Pilot prospective randomized, controlled clinical trial.

SETTING

Outpatient rehabilitation specialty hospital.

PARTICIPANTS

Eighteen individuals with CMISCI with American Spinal Injury Association (ASIA) level between C4 and L2 and at least one-year post injury. Interventions CMISCI participants were randomized to RABWSTT or a home stretching program (HSP) three times per week for three months. Those in the home stretching group were crossed over to three months of RABWSTT following completion of the initial three month phase.

OUTCOME MEASURES

Peak oxygen consumption (peak VO(2)) was measured during both robotic treadmill walking and arm cycle ergometry: twice at baseline, once at six weeks (mid-training) and twice at three months (post-training). Peak VO(2) values were normalized for body mass.

RESULTS

The RABWSTT group improved peak VO(2) by 12.3% during robotic treadmill walking (20.2 ± 7.4 to 22.7 ± 7.5 ml/kg/min, P = 0.018), compared to a non-significant 3.9% within group change observed in HSP controls (P = 0.37). Neither group displayed a significant change in peak VO2 during arm cycle ergometry (RABWSTT, 8.5% (P = 0.25); HSP, 1.76% (P = 0.72)). A repeated measures analysis showed statistically significant differences between treatments for peak VO(2) during both robotic treadmill walking (P = 0.002) and arm cycle ergometry (P = 0.001).

CONCLUSION

RABWSTT is an effective intervention model for improving peak fitness levels assessed during robotic treadmill walking in persons with CMISCI.

Exercise and its interactions with various aspects of man and animal lives

To review recently published papers in the Brazilian Scientific press on the general subject of physical exercise. All articles published in 2010/2011 found through the keyword exercise were collected from 11 Brazilian Journals. They were hand filtered to exclude all but original research papers. They were grouped according to subject categories and subcategories. A brief summary of all included articles was produced, comparing similar articles between them. The most commonly found interactions refer to exercise vs. the cardiovascular system, metabolism and the locomotor system, in this order. The volume of scientific research in the field is high and of sufficient quality to justify highlighting.

Pulmonary research recently published in Brazilian journals

We reviewed original articles in the field of pulmonary medicine that had been recently published in 12 Brazilian journals--general or specialty journals--excluding the Brazilian Journal of Pulmonology. All were journals indexed for the Institute for Scientific Information Web of Knowledge. The selection of articles was based on the "continuously variable rating" concept. We have organized the articles by category.