The development and pilot randomised controlled trial of a group education programme for promoting walking in people with intermittent claudication

The aim of this study was to develop and pilot a group education programme for promoting walking in people with intermittent claudication. Patient focus groups (n=24) and literature reviews were conducted to inform the development of the education programme, which involves a three-hour group-based education workshop and follow-up telephone support. A pilot study was subsequently conducted in which 23 new patients (Rutherford category 1-3) were randomly assigned to usual care (control) or usual care plus the education programme. Outcomes were assessed at baseline and six weeks including daily steps (tri-axial accelerometer), walking capacity (six-minute walk test and Gardner treadmill test), and quality of life (Intermittent Claudication Questionnaire [ICQ]). Exit interviews were conducted to assess the acceptability and usefulness of the programme. Compared with controls, the intervention group had superior walking capacity and quality of life at six weeks. Mean differences in six-minute walk distance, treadmill maximum walking distance and ICQ score were 44.9 m (95% confidence interval [CI], 6.9 to 82.9), 173 m (95% CI, 23 to 322), and -10.6 (95% CI, -18.9 to -2.3), respectively. The daily step count did not differ between groups. The exit interviews indicated that participants valued attending the programme, that it gave them a greater understanding of their condition, and that they had been walking more for exercise since attending. The results suggest that the education programme is feasible, acceptable, and potentially useful for improving walking capacity and quality of life. A fully-powered trial exploring clinical and cost effectiveness is needed.

TRIAL REGISTRATION NUMBER

ISRCTN06733130 (http://www.controlled-trials.com).

Plasma cytokine and exertional responses in relation to exercise intensity and volume of exercising muscle mass during arm-crank ergometry

This original study investigated the effect of submaximal exercise intensity and volume of contracting muscle mass on plasma inflammation-mediating cytokine and perceived exertional responses to acute arm-crank ergometry (ACE). Twelve recreationally active but upper limb untrained males performed 30 min of (i) low-intensity (40% peak oxygen uptake) ACE (LOW); (ii) moderate-intensity (60% peak oxygen uptake) ACE (MOD); and (iii) concurrent low-intensity (40% peak oxygen uptake) ACE plus lower limb cycle ergometry to match total power output in MOD (HYB). Plasma concentrations of interleukin (IL)-6, IL-10, IL-1ra, adrenaline, and cortisol were determined at rest, immediately postexercise, and 1 h and 2 h postexercise. Heart rate (HR) and differentiated ratings of perceived exertion (RPE) were also recorded. Plasma IL-6 concentrations were elevated (p < 0.05) immediately postexercise and 1 h postexercise (∼ 2.5-fold) in all trials and 2 h postexercise in MOD (3-fold). Plasma IL-1ra concentrations were elevated (p < 0.05) 2 h postexercise in MOD only (2-fold). No plasma IL-10, cortisol, and adrenaline responses were observed. HR and differentiated RPE were significantly higher during MOD than HYB and LOW. Peripheral RPE were significantly higher than central and overall RPE in each trial. Thirty minutes of moderate intensity ACE initiated a plasma cytokine response associated with the protective effect of regular exercise against cardiovascular and metabolic disease risk. Further work is required to establish an optimal intensity and duration of upper limb exercise to maximise the anti-inflammatory potential whilst managing the risk of over-use injury.

Step-monitored home exercise improves ambulation, vascular function, and inflammation in symptomatic patients with peripheral artery disease: a randomized controlled trial

Background

This prospective, randomized, controlled clinical trial compared changes in primary outcome measures of claudication onset time (COT) and peak walking time (PWT), and secondary outcomes of submaximal exercise performance, daily ambulatory activity, vascular function, inflammation, and calf muscle hemoglobin oxygen saturation (StO₂) in patients with symptomatic peripheral artery disease (PAD) following new exercise training using a step watch (NEXT Step) home‐exercise program, a supervised exercise program, and an attention‐control group.

Methods and Results

One hundred eighty patients were randomized. The NEXT Step program and the supervised exercise program consisted of intermittent walking to mild‐to‐moderate claudication pain for 12 weeks, whereas the controls performed light resistance training. Change scores for COT (P<0.001), PWT (P<0.001), 6‐minute walk distance (P=0.028), daily average cadence (P=0.011), time to minimum calf muscle StO₂ during exercise (P=0.025), large‐artery elasticity index (LAEI) (P=0.012), and high‐sensitivity C‐reactive protein (hsCRP) (P=0.041) were significantly different among the 3 groups. Both the NEXT Step home program and the supervised exercise program demonstrated a significant increase from baseline in COT, PWT, 6‐minute walk distance, daily average cadence, and time to minimum calf StO₂. Only the NEXT Step home group had improvements from baseline in LAEI, and hsCRP (P<0.05).

Conclusions

NEXT Step home exercise utilizing minimal staff supervision has low attrition, high adherence, and is efficacious in improving COT and PWT, as well as secondary outcomes of submaximal exercise performance, daily ambulatory activity, vascular function, inflammation, and calf muscle StO₂ in symptomatic patients with PAD.

Clinical Trial Registration

URL: ClinicalTrials.gov. Unique Identifier: NCT00618670.

Exercise for intermittent claudication

BACKGROUND

Exercise programmes are a relatively inexpensive, low-risk option compared with other more invasive therapies for leg pain on walking (intermittent claudication (IC)). This is an update of a review first published in 1998.

OBJECTIVES

The prime objective of this review was to determine whether an exercise programme in people with intermittent claudication was effective in alleviating symptoms and increasing walking treadmill distances and walking times. Secondary objectives were to determine whether exercise was effective in preventing deterioration of underlying disease, reducing cardiovascular events and improving quality of life.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched September 2013) and CENTRAL (2013, Issue 8).

SELECTION CRITERIA

Randomised controlled trials of an exercise regimen versus control or versus medical therapy in people with IC due to peripheral arterial disease. Any exercise programme or regimen used in the treatment of intermittent claudication was included, such as walking, skipping and running. Inclusion of trials was not affected by the duration, frequency or intensity of the exercise programme. Outcome measures collected included treadmill walking distance (time to onset of pain or pain-free walking distance and maximum walking time or maximal walking distance), ankle brachial index (ABI), quality of life, morbidity or amputation; if none of these were reported the trial was not included in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

Eleven additional studies were included in this update making a total of 30 trials which met the inclusion criteria, involving a total of 1816 participants with stable leg pain. The follow-up period ranged from two weeks to two years. The types of exercise varied from strength training to polestriding and upper or lower limb exercises; generally supervised sessions were at least twice a week. Most trials used a treadmill walking test for one of the outcome measures. Quality of the included trials was moderate, mainly due to an absence of relevant information. The majority of trials were small with 20 to 49 participants. Twenty trials compared exercise with usual care or placebo, the remainder of the trials compared exercise to medication (pentoxifylline, iloprost, antiplatelet agents and vitamin E) or pneumatic calf compression; people with various medical conditions or other pre-existing limitations to their exercise capacity were generally excluded.Overall, when taking the first time point reported in each of the studies, exercise significantly improved maximal walking time when compared with usual care or placebo: mean difference (MD) 4.51 minutes (95% confidence interval (CI) 3.11 to 5.92) with an overall improvement in walking ability of approximately 50% to 200%. Walking distances were also significantly improved: pain-free walking distance MD 82.29 metres (95% CI 71.86 to 92.72) and maximum walking distance MD 108.99 metres (95% CI 38.20 to 179.78). Improvements were seen for up to two years, and subgroup analyses were performed at three, six and 12 months where possible. Exercise did not improve the ABI (MD 0.05, 95% CI 0.00 to 0.09). The effect of exercise, when compared with placebo or usual care, was inconclusive on mortality, amputation and peak exercise calf blood flow due to limited data. No data were given on non-fatal cardiovascular events.Quality of life measured using the Short Form (SF)-36 was reported at three and six months. At three months, physical function, vitality and role physical all significantly improved with exercise, however this was a limited finding as this measure was only reported in two trials. At six months five trials reported outcomes of a significantly improved physical summary score and mental summary score secondary to exercise. Only two trials reported improvements in other domains, physical function and general health.Evidence was generally limited for exercise compared with antiplatelet therapy, pentoxifylline, iloprost, vitamin E and pneumatic foot and calf compression due to small numbers of trials and participants.

AUTHORS' CONCLUSIONS

Exercise programmes are of significant benefit compared with placebo or usual care in improving walking time and distance in people with leg pain from IC who were considered to be fit for exercise intervention.

V.O2 Kinetics and clinical factors among patients with peripheral artery disease

PURPOSE

To investigate the association between oxygen uptake (V.O2) kinetics and demographic, behavioral, and clinical factors among patients with peripheral artery disease (PAD).

METHODS

A total of 85 PAD patients with intermittent claudication performed a constant load treadmill test, and breath-by-breath (V.e.)O2 was obtained to assess V.O2 kinetics. Demographic information, anthropometry, cardiovascular risk factors, and comorbid conditions were recorded.

RESULTS

Using univariate analyses, higher values of tau ([τ], i.e., slowed V.O2 kinetics) were associated with female gender, non-Caucasian race, hypertension, dyslipidemia, and age ≤66 years. Smoking, diabetes, obesity, metabolic syndrome, height, and ankle brachial index were not significantly related to V.O2 kinetics. Using multiple regression procedures, the identified predictors of slowed V.O2 kinetics were female gender (4.76 [95% CI: 1.49-8.03] seconds; P = .0049), non-Caucasian race (4.70 [95% CI: 1.29-8.12] seconds; P = .0075), hypertension (12.06 [95% CI: 8.83-15.28] seconds; P < .0001), and age ≤66 years (4.97 [95% CI: 1.95-7.99] seconds; P = .0015).

CONCLUSIONS

In PAD patients, slowed V.O2 kinetics are associated with demographic and clinical factors. The clinical significance is that female, non-Caucasian, and hypertensive PAD patients present central and/or peripheral limitations that may partially account for their walking impairment.

The effect of arm training on thermoregulatory responses and calf volume during upper body exercise

PURPOSE

The smaller muscle mass of the upper body compared to the lower body may elicit a smaller thermoregulatory stimulus during exercise and thus produce novel training-induced thermoregulatory adaptations. Therefore, the principal aim of the study was to examine the effect of arm training on thermoregulatory responses during submaximal exercise.

METHODS

Thirteen healthy male participants (Mean ± SD age 27.8 ± 5.0 years, body mass 74.8 ± 9.5 kg) took part in 8 weeks of arm crank ergometry training. Thermoregulatory and calf blood flow responses were measured during 30 min of arm cranking at 60% peak power (W peak) pre-, and post-training and post-training at the same absolute intensity as pre-training. Core temperature and skin temperatures were measured, along with heat flow at the calf, thigh, upper arm and chest. Calf blood flow using venous occlusion plethysmography was performed pre- and post-exercise and calf volume was determined during exercise.

RESULTS

The upper body training reduced aural temperature (0.1 ± 0.3 °C) and heat storage (0.3 ± 0.2 J g(-1)) at a given power output as a result of increased whole body sweating and heat flow. Arm crank training produced a smaller change in calf volume post-training at the same absolute exercise intensity (-1.2 ± 0.8% compared to -2.2 ± 0.9% pre-training; P < 0.05) suggesting reduced leg vasoconstriction.

CONCLUSION

Training improved the main markers of aerobic fitness. However, the results of this study suggest arm crank training additionally elicits physiological responses specific to the lower body which may aid thermoregulation.

The effect of exercise on fitness and performance-based tests of function in intermittent claudication: a systematic review

BACKGROUND AND OBJECTIVE

Exercise is a widely accepted treatment known to improve walking ability in persons with peripheral arterial disease (PAD); however, it has not been confirmed as to whether exercise improves fitness and performance-based function and, consequently, performance of activities of daily living (ADL). This systematic review aims to identify whether any mode of structured exercise improves physical fitness or performance-based tests of function and whether improvement in walking ability is related to an improvement in these outcomes.

DATA SOURCES AND STUDY SELECTION

Eligible studies included randomized controlled trials (RCTs) using an exercise intervention for the treatment of intermittent claudication with fitness (including the 6-min walk (6MW), aerobic capacity, shuttle and muscle strength) tests and performance-based tests of function as the outcomes. STUDY APPRAISAL AND METHODS: Assessment of study quality was performed using a modified version of the Physiotherapy Evidence Database Scale (PEDro). Relative effect sizes, mean differences (MDs) and 95 % confidence intervals were calculated and adjusted via Hedges' bias-corrected for small sample sizes. Regression analyses were performed to establish relationships between walking ability and fitness outcomes.

RESULTS

Twenty-four RCTs met the inclusion criteria: 19 aerobic training interventions and 5 progressive resistance training (PRT). In total 924 participants (71 % male) were studied; with few participants over 75 years of age and the mean ankle brachial index was mean ± standard deviation (SD) 0.66 ± 0.06. The most common outcome measured was aerobic capacity (52 % of trials), which improved by 8.3 % ± 8.7 % on average. Although there were no significant relationships, up to 16 % of the variance in walking distances can be explained by changes in walking economy. Muscle strength was measured in only five trials, improving by 42 % ± 74 % on average. There was a strong significant relationship between change in plantar flexor muscle strength and change in initial claudication time (r = 0.99; p = 0.001) and absolute claudication time (r = 0.75; p = 0.05) measured on a treadmill across trials measuring this muscle group. The 6MW distance was measured in only 14 % of trials. Walking and PRT significantly improved 6MW initial claudication distance (MD range 52-129 m) and total walking distance (MD range 36-108 m) in studies that measured this outcome. Only one trial assessed performance-based tests of function, and they did not improve significantly.

CONCLUSION

Although data are limited, there is a strong significant relationship between plantar flexor muscle strength and treadmill walking ability. More research is needed to assess improvements in walking economy at specific timepoints and whether this translates to improvements in claudication outcomes and measurements pertaining to muscle strength. Future trials should focus on interventions that improve lower limb muscle strength and assess muscle strength, power and endurance across a variety of lower extremity muscle groups in order to understand these relationships further. The 6MW, muscle strength and performance-based tests of function such as chair stand, balance scale, stair climb and gait speed are understudied in PAD. Future trials should examine the effects of exercise on performance-based tests of function, which may predict actual ADL performance and incident disability.

Effects of exercise on fitness and cognition in progressive MS: a randomized, controlled pilot trial

Background:

Exercise may have beneficial effects on both well-being and walking ability in multiple sclerosis (MS). Exercise is shown to be neuroprotective in rodents and may also enhance cognitive function in humans. It may, therefore, be particularly useful for MS patients with pronounced neurodegeneration.

Objective:

To investigate the potential of standardized exercise as a therapeutic intervention for progressive MS, in a randomized-controlled pilot trial.

Methods:

Patients with progressive MS and moderate disability (Expanded Disability Status Scale (EDSS) of 4–6) were randomized to one of three exercise interventions (arm ergometry, rowing, bicycle ergometry) for 8–10 weeks or a waitlist control group. We analyzed the drop-out rate as a measure of feasibility. The primary endpoint of the study was aerobic fitness. Secondary endpoints were walking ability, cognitive function as measured by a neuropsychological test battery, depression and fatigue.

Results:

A total of 42 patients completed the trial (10.6% drop-out rate). Significant improvements were seen in aerobic fitness. In addition, exercise improved walking ability, depressive symptoms, fatigue and several domains of cognitive function.

Conclusion:

This study indicated that aerobic training is feasible and could be beneficial for patients with progressive MS. Larger exercise studies are needed to confirm the effect on cognition.

Trial Registration:

ISRCTN (trial number 76467492) http://isrctn.org

Supervised exercise therapy versus non-supervised exercise therapy for intermittent claudication

BACKGROUND

Although supervised exercise therapy is considered to be of significant benefit for people with leg pain (peripheral arterial disease (PAD)), implementing supervised exercise programs (SETs) in daily practice has limitations. This is an update of a review first published in 2006.

OBJECTIVES

The main objective of this review was to provide an accurate overview of studies evaluating the effects of supervised versus non-supervised exercise therapy on maximal walking time or distance on a treadmill for people with intermittent claudication.

SEARCH METHODS

For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched September 2012) and CENTRAL (2012, Issue 9). In addition, we handsearched the reference lists of relevant articles for additional trials. No restriction was applied to language of publication.

SELECTION CRITERIA

Randomized clinical trials comparing supervised exercise programs with non-supervised exercise programs (defined as walking advice or a structural home-based exercise program) for people with intermittent claudication. Studies with control groups, which did not receive exercise or walking advice or received usual care (maintained normal physical activity), were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors (HJPF and BLWB) independently selected trials and extracted data. Three review authors (HJPF, BLWB, and GJL) assessed trial quality, and this was confirmed by two other review authors (MHP and JAWT). For all continuous outcomes, we extracted the number of participants, the mean differences, and the standard deviation. The 36-Item Short Form Health Survey (SF-36) outcomes were extracted to assess quality of life. Effect sizes were calculated as the difference in treatment normalized with the standard deviation (standardized mean difference) using a fixed-effect model.

MAIN RESULTS

A total of 14 studies involving a total of 1002 male and female participants with PAD were included in this review. Follow-up ranged from six weeks to 12 months. In general, supervised exercise regimens consisted of three exercise sessions per week. All trials used a treadmill walking test as one of the outcome measures. The overall quality of the included trials was moderate to good, although some trials were small with respect to the number of participants, ranging from 20 to 304.Supervised exercise therapy (SET) showed statistically significant improvement in maximal treadmill walking distance compared with non-supervised exercise therapy regimens, with an overall effect size of 0.69 (95% confidence interval (CI) 0.51 to 0.86) and 0.48 (95% CI 0.32 to 0.64) at three and six months, respectively. This translates to an increase in walking distance of approximately 180 meters that favored the supervised group. SET was still beneficial for maximal and pain-free walking distances at 12 months, but it did not have a significant effect on quality of life parameters.

AUTHORS' CONCLUSIONS

SET has statistically significant benefit on treadmill walking distance (maximal and pain-free) compared with non-supervised regimens. However, the clinical relevance of this has not been demonstrated definitively; additional studies are required that focus on quality of life or other disease-specific functional outcomes, such as walking behavior, patient satisfaction, costs, and long-term follow-up. Professionals in the vascular field should make SET available for all patients with intermittent claudication.

[Vascular rehabilitation in patients with peripheral arterial disease]

Lower limb peripheral arterial disease (PAD) is a frequent debilitating disease associated with a high morbidity and mortality rate. The benefit of rehabilitation in PAD patients has been largely demonstrated, both for patients that undergo amputation, and for patients with claudication. In these latter patients, rehabilitation programs rely on a variety of additional techniques or tools, among which: stretching, specific muscle proprioception, walking and a variety of other physical activities, exercise or situations adapted to community life, lower limb and respiratory physiotherapy, patient's education, support for smoking cessation and healthy nutrition, social support, etc. Whether rehabilitation is performed in specialised integrated structures or performed on a home-based basis, various clinicians are involved. Despite evidence-based proof of efficacy, rehabilitation of PAD patients with claudication is still under-used.

Exercise therapy for claudication: latest advances

OPINION STATEMENT

Peripheral artery disease (PAD) creates a significant national and international healthcare burden. A first line treatment for PAD is supervised walking exercise in hospitals and clinics. Specifically, supervised walking exercise seeks to improve the classic symptom associated with PAD, intermittent claudication (IC), which is characterized by cramping, aching, and pain of the muscles in the lower extremities during walking. While effective, supervised walking exercise is often not prescribed or utilized due to a number of treatment barriers such as lack of transportation to clinical centers and lack of insurance reimbursement. Walking exercise in community settings is an option that has gained attention due to the limitations of supervised walking exercise, as community walking is generally more convenient in terms of a patient's schedule and may circumvent potential barriers such as treatment cost and transportation difficulties. However, more research is needed to improve the effectiveness of community-based walking programs since far less is known about the optimal structure of such programs. Other exercise therapy options are becoming available for PAD patients in addition to walking exercise. These modalities include but are not limited to leg and arm ergometry, polestriding and resistance training. These exercise therapy options have not to date been as well validated as supervised walking exercise. However, they may potentially be used in the event supervised walking exercise is not feasible or patient preference warrants an alternative exercise strategy.

The Effects of Walking or Walking-with-Poles Training on Tissue Oxygenation in Patients with Peripheral Arterial Disease

This randomized trial proposed to determine if there were differences in calf muscle StO₂ parameters in patients before and after 12 weeks of a traditional walking or walking-with-poles exercise program. Data were collected on 85 patients who were randomized to a traditional walking program (n = 40) or walking-with-poles program (n = 45) of exercise training. Patients walked for 3 times weekly for 12 weeks. Seventy-one patients completed both the baseline and the 12-week follow-up progressive treadmill tests (n = 36 traditional walking and n = 35 walking-with-poles). Using the near-infrared spectroscopy measures, StO₂ was measured prior to, during, and after exercise. At baseline, calf muscle oxygenation decreased from 56 ± 17% prior to the treadmill test to 16 ± 18% at peak exercise. The time elapsed prior to reaching nadir StO₂ values increased more in the traditional walking group when compared to the walking-with-poles group. Likewise, absolute walking time increased more in the traditional walking group than in the walking-with-poles group. Tissue oxygenation decline during treadmill testing was less for patients assigned to a 12-week traditional walking program when compared to those assigned to a 12-week walking-with-poles program. In conclusion, the 12-week traditional walking program was superior to walking-with-poles in improving tissue deoxygenation in patients with PAD.

Clinical significance of ankle systolic blood pressure following exercise in assessing calf muscle tissue ischemia in peripheral artery disease

Our primary objective assessed whether a decline in ankle systolic blood pressure (SBP) to less than 50 mm Hg after treadmill exercise is associated with lower extremity ischemia, as measured by calf muscle hemoglobin oxygen saturation (StO(2)). Eighty-four patients with peripheral artery disease (PAD) completed a treadmill test. Ankle SBP <50 mm Hg following exercise was observed in only 49% (group 1), whereas 51% had ankle SBP ≥50 mm Hg (group 2). No group differences were observed for the decline in calf muscle StO(2) to a minimum value (group 1: 18 ± 21%, group 2: 20 ± 20%; P = .60) and for the time to reach minimum StO(2) (group 1: 224 ± 251 seconds, group 2: 284 ± 283 seconds; P = .30). Requirement of ankle SBP to decrease below 50 mm Hg after exercise has little clinical significance for assessing ischemia in calf muscle of patients with PAD limited by intermittent claudication.

Optimal exercise program length for patients with claudication

BACKGROUND

This prospective, randomized controlled clinical trial determined whether an optimal exercise program length exists to efficaciously change claudication onset time (COT) and peak walking time (PWT) in patients with peripheral artery disease and claudication.

METHODS

The study randomized 142 patients to supervised exercise (n = 106) or a usual care control group (n = 36), with 80 completing the exercise program and 27 completing the control intervention. The exercise program consisted of intermittent walking to nearly maximal claudication pain 3 days per week. COT and PWT were the primary outcomes obtained from a treadmill exercise test at baseline and bimonthly during the study.

RESULTS

After exercise, changes in COT (P < .001) and PWT (P < .001) were consistently greater than changes after the control intervention. In the exercise program, COT and PWT increased from baseline to month 2 (P < .05) and from months 2 to 4 (P < .05) but did not significantly change from months 4 to 6 (P > .05). When changes were expressed per mile walked during the first 2 months, middle 2 months, and final 2 months of exercise, COT and PWT only increased during the first 2 months (P < .05).

CONCLUSIONS

Exercise-mediated gains in COT and PWT occur rapidly within the first 2 months of exercise rehabilitation and are maintained with further training. The clinical significance is that a relatively short 2-month exercise program may be preferred to a longer program to treat claudication because adherence is higher, costs associated with personnel and use of facilities are lower per patient, and more patients can be trained for a given amount of personnel time and resource utilization.

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease

The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal–Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.

Muscle perfusion of posterior trunk and lower-limb muscles at rest and during upper-limb exercise in spinal cord-injured and able-bodied individuals

STUDY DESIGN

Nonrandomized-controlled trial.

OBJECTIVES

To assess muscle perfusion at rest and during arm-cranking exercise (ACE) in upper and lower posterior trunk and vastus lateralis (VL) muscles in individuals with spinal cord injury (SCI) and controls (C).

SETTING

Exercise Physiology-Biochemistry Laboratory.

METHODS

Eight SCI with thoracic lesion and eight C received injections of radioactive tracer to trapezius (TRAP), latissimus dorsi (LAT) and VL. Radioactive counts were recorded with a γ-camera for 10 min at rest and during ACE (60% VO(2max) for 20 min). Time-count curves were generated and the isotope clearance rate, expressed as half-life time (T(1/2),min), was calculated to assess muscle perfusion.

RESULTS

Resting T(1/2) was lower in TRAP and LAT vs VL (P<0.05) in SCI, however, there were no differences among muscles in C. Arm-cranking increased (P<0.001) the isotope clearance in TRAP and LAT in SCI and C, whereas no effect was found on T(1/2) in VL in both groups. T(1/2) was longer (P<0.05) in SCI vs C in VL at rest and during ACE, whereas there were no differences between groups in posterior trunk muscles.

CONCLUSIONS

Resting muscle perfusion was reduced in the paralyzed limbs of SCI compared with C, whereas there was no evidence of impaired microcirculation in upper and lower back muscles in SCI. Although ACE did not induce a hyperemic response in VL, it increased hyperemia in upper and lower posterior trunk muscles in SCI, suggesting beneficial effects of this type of activity on muscle microvasculature in this region.

Comparison of the effect of upper body-ergometry aerobic training vs treadmill training on central cardiorespiratory improvement and walking distance in patients with claudication

BACKGROUND

Supervised treadmill-walking exercise programs have been proven to be a highly effective in improving walking distance in peripheral arterial disease (PAD) patients with lifestyle-limiting claudication. Limited information is available on the contributions of central cardiorespiratory functions for improving these patients' walking capacity with exercise training.

METHODS

This study randomized 28 participants (21 men; age, 65.6 years; 92.7% smoking history, 36.6% with diabetes) with lifestyle-limiting PAD-related claudication to 3 hours/week of supervised exercise training for 12 weeks, using arm-ergometry (n = 10) or treadmill-walking (n = 10) vs a usual-care control group (n = 8). Cardiorespiratory function measurements were assessed before and after training at a submaximal workload and at the onset of claudication (pain-free walking distance [PFWD]) and at maximal walking distance [(MWD]). Changes in these functions from baseline were analyzed among the groups with analysis of covariance. Associations between variables were determined by Pearson's partial correlations.

RESULTS

The mean baseline demographic, medical, and exercise variables were similar among the groups. There were similar significant differences in the submaximal double product (heart rate × systolic blood pressure) and at MWD, ventilatory threshold, ventilatory oxygen uptake (VO(2)) at onset of claudication, and VO(2) peak in response to training in both exercise groups vs the control group. Statistically significant, moderate correlations (r = 0.60-0.68) were found between changes in all cardiorespiratory variables and changes in PFWD or MWD.

CONCLUSION

Improvements in cardiorespiratory function after arm-ergometry or treadmill-training were significantly associated with improvements in both PFWD and MWD, providing supporting evidence of systemic contributions to exercise training-related improvements in walking capacity seen in patients with claudication.

The effects of an increasing versus constant crank rate on peak physiological responses during incremental arm crank ergometry

We examined the effects of concomitant increases in crank rate and power output on incremental arm crank ergometry. Ten healthy males undertook three incremental upper body exercise tests to volitional exhaustion. The first test determined peak minute power. The subsequent tests involved arm cranking at an initial workload of 40% peak minute power with further increases of 10% peak minute power every 2 min. One involved a constant crank rate of 70 rev · min(-1), the other an initial crank rate of 50 rev · min(-1) increasing by 10 rev · min(-1) every 2 min. Fingertip capillary blood samples were analysed for blood lactate at rest and exhaustion. Local (working muscles) and cardiorespiratory ratings of perceived exertion (RPE) were recorded at the end of each exercise stage. Heart rate and expired gas were monitored continuously. No differences were observed in peak physiological responses or peak minute power achieved during either protocol. Blood lactate concentration tended to be greater for the constant crank rate protocol (P = 0.06). Test duration was shorter for the increasing than for the constant crank rate protocol. The relationship between local RPE and heart rate differed between tests. The results of this study show that increasing cadence during incremental arm crank ergometry provides a valid assessment of peak responses over a shorter duration but alters the heart rate-local RPE relationship.

Effects of upper-limb exercise on lower-limb cutaneous microvascular function in post-surgical varicose-vein patients

Regular walking exercise attenuates lower-limb cutaneous microvascular endothelial dysfunction in post-surgical varicose-vein patients. This study assessed the effects of upper-limb exercise training on lower-limb cutaneous microvascular function in this patient group. Six post-surgical (4-5 weeks) varicose-vein patients completed an 8-week arm-crank exercise training programme. Changes in cutaneous microvascular function of the lower leg were assessed using laser Doppler flowmetry and iontophoretic administration of endothelial-dependent and -independent agonists [acetylcholine (ACh) and sodium nitroprusside (SNP), respectively]. At 8 weeks, median lower-limb cutaneous vasodilator responsives to ACh and SNP remained unchanged relative to baseline (e.g. 6 mC: 37 (interquartile range 24-63) vs. 40 (20-71) PU and 35 (23-48) vs. 38 (21-64) PU, respectively for the supine position). Upper-limb exercise appears ineffective for improving lower-limb cutaneous microvascular function in post-surgical varicose-vein patients. Therefore, limb specificity appears an important factor in optimal exercise prescription for these patients.