Exploring adaptations to the modified shuttle walking test

Is an 8-Week Regimen of Nordic Walking Training Sufficient to Benefit Cognitive Performance in Healthy Older Adults? A Pilot Study

Nordic walking requires the association of walking and coordination of limbs while orienteering in a natural environment. It has been shown to improve functional capacities more than normal walking. However, its cognitive benefits are less clear. The main hypothesis was that this training improves visuospatial capacities and inhibition functions. A total of 14 healthy older adults were included. The training was performed in three sessions of 75 min a week for 8 weeks. Pre-, intermediate, and post-tests were carried out. Cognitive functions including global cognition (MoCA), executive functions (Color-Word Stroop test), speed of information processing, switching capacities (Trail Making Test A and B), and visuospatial capacities (Rey Complex Figure Copy Task) were assessed. Motor functions including balance control (Unipedal Balance Test), functional mobility (Timed Up and Go), hamstring flexibility (Chair Sit and Reach test), and motor coordination (Four-Square Stepping Test) were evaluated. Physical function, including lower limb strength (Timed Sit-To-Stand) and cardiovascular capacities (Incremental Shuttle Walking Test), was measured. Cardiovascular capacity, strength of lower limbs, and motor coordination were positively affected by training. With respect to cognition, training improved visuospatial capacities, while switching capacities, information processing speed, and executive functions did not improve. A possible explanation is that they needed a longer program duration to show benefits. However, analyses of responders suggested that NW positively affected cognitive functioning in a subset of participants. Eight weeks of NW training produced physical, motor, and cognitive improvements. A longer training duration could be necessary to extend the benefits to executive functions in all participants.

Shuttle walk test categorization according to the qualifiers of the International Classification of Functioning, Disability, and Health: proposal for use in patients with difficult-to-treat asthma, a cross-sectional study

AIM

To classify functional capacity of people with difficult-to-treat asthma based on the International Classification of Functioning, Disability and Health (ICF).

METHODS

Fifty-seven patients underwent the Incremental Shuttle Walk Test (ISWT) to assess functional capacity, in order to categorize them functionally we used the ICF qualifiers. To qualify ISWT results the individual's impairment (i.e. percentage of distance walked in relation to the percentage of predicted) was analyzed. Additionally, body mass index (BMI); physical activity level (IPAQ); and pulmonary function were evaluated. In order to analyze the difference between functional capacity levels, two groups were compared (i.e. mild/moderate vs. severe impairment); therefore, the participants were matched according to age and BMI and the unpaired Student t test was used.

RESULTS

Among the fifty-seven included individuals, only one (1.8%) presented mild functional capacity limitation, 12 (21.1%) moderate limitation and 44 (77.2%) severe limitation. There was a significant difference between the ISWT distance between groups (F = 0.217, p < .001). The other variables did not present differences between the mild/moderate and severe groups.

CONCLUSION

The ICF qualifiers were able to categorize the ISWT and classified the functional capacity limitation as mild, moderate and severe. Therefore, it has proved to be a useful clinical tool for evaluation, follow-up and clinical decision-making.

Comparison of Three Physical-Cognitive Training Programs in Healthy Older Adults: A Study Protocol for a Monocentric Randomized Trial

(1) Combining aerobic, coordination and cognitive training allows for more improved physical and cognitive performance than when performed separately. A Nordic walking (NW) and two cognitive-motor circuit training programs (CT-c and CT-fit) are compared. CT-c and CT-fit stimulate cognition differently: CT-c, is through conventional complex coordination training performed in single and dual-task conditions; CT-fit, incorporates it into complex goal-directed actions, implemented by fitness gaming technology (2) The aim is to determine whether CT-fit brings additional benefits to cognition compared to more traditional training. (3) Forty-five healthy independent living community dwellers participants (65–80 years) will be included after a general medical examination. The main exclusion criteria are signs of cognitive impairments (Mini–Mental State Examination < 26/30) and physical impairments. Pre and post-tests will be performed to assess: cognitive functions (Montreal Cognitive Assessment; Trail Making Test; Stroop task, working memory test, Rey Complex Figure copy task, Oral Trail Making Test, and dual-task); motor fitness (Bipedal and unipedal balance test, gait assessments, Time Up and Go, chair sit and reach test and four-square stepping test); and physical fitness (10 m incremental shuttle walking test, maximal handgrip force, Timed-Stands test). (4) Incorporating cognitive demands into complex, goal-directed actions using fitness gaming technology should be the best solution to optimize training benefits.

Predicting the rate of oxygen consumption during the 3-minute constant-rate stair stepping and shuttle tests in people with chronic obstructive pulmonary disease

Background

The 3-minute constant-rate stair stepping (3-min CRSST) and constant-speed shuttle tests (3-min CSST) were developed to assess breathlessness in response to a standardized exercise stimulus. Estimating the rate of oxygen consumption (V’O₂) during these tests would assist clinicians to relate the stepping/shuttle speeds that elicit breathlessness to daily physical activities with a similar metabolic demand. This study: (I) developed equations to estimate the V’O₂ of these tests in people with chronic obstructive pulmonary disease (COPD); and (II) compared the newly developed and American College of Sports Medicine (ACSM) metabolic equations for estimating the V’O₂ of these tests.

Methods

This study was a retrospective analysis of people with COPD who completed a 3-min CRSST (n=98) or 3-min CSST (n=69). Multivariate linear regression estimated predictors (alpha <0.05) of V’O₂ to construct COPD-specific metabolic equations. The mean squared error (MSE) of the COPD-specific and ACSM equations was calculated and compared. Bland-Altman analyses evaluated level of agreement between measured and predicted V’O₂ using each equation; limits of agreement (LoA) and patterns of bias were compared.

Results

Stepping rate/shuttle speed and body mass were identified as significant predictors of V’O₂. The MSE of the COPD-specific equations was 0.05 L·min⁻¹ for both tests. Mean difference between measured and predicted V’O₂ was 0.00 L·min⁻¹ (95% LoA −0.46, 0.46) and 0.00 L·min⁻¹ (95% LoA −0.44, 0.44) for the 3-min CRSST and 3-min CSST, respectively. For the ACSM metabolic equations, the MSE was 0.10 L·min⁻¹ and 0.18 L·min⁻¹ for the 3-min CRSST and 3-min CSST, respectively. The ACSM metabolic equations underestimated V’O₂ of the 3-min CRSST by −0.18 L·min⁻¹ (95% LoA −0.68, 0.32), and overestimated V’O₂ of the 3-min CSST by 0.35 L·min⁻¹ (95% LoA −0.14, 0.84).

Conclusions

This study presents metabolic equations to predict V’O2 of the 3-min CRSST and 3-min CSST for people with COPD that are more accurate than the ACSM metabolic equations.

Metabolic equivalents fail to indicate metabolic load in post-myocardial infarction patients during the modified Bruce treadmill walking test

AIM

To investigate the suitability of metabolic equivalents (METs) for determining exercise intensity in phase-IV post-myocardial infarction (MI) men during the modified Bruce treadmill walking test (MBWT).

METHODS

Twenty phase-IV post-MI men (mean±SD, aged 64.4±5.8 years) and 20 healthy non-cardiac male controls (59.8±7.6 years) participated. Participants performed a MBWT. Throughout the participants' heart rate (HR), heart rhythm, expired air parameters and ratings of perceived exertion (RPEs) were measured. MET values were compared between groups and those currently ascribed to each stage of the MBWT.

RESULTS

General linear model analysis found no significant differences between groups during the MBWT for VO2, VCO2, HR, METs or RPEs (Borg 6-20 scale). Ascribed METs did not differ from mean METs of post-MIs or controls other than at stage 5 where post-MI METs were significantly lower. Irrespective, the post-MI group worked at a higher percentage of their anaerobic threshold (AT) (respiratory exchange ratio, RER=1.0) (F(2,5)=7.22, p<0.008), higher RER (F(2,5)=11.25, p<0.001) with increased breathing frequency (F(2,5)=7.22, p<0.001). Regression analysis revealed AT to be VO2 25.6 (mL/kg/min) for post-MI versus VO2 31.1 (mL/kg/min) for controls. Gross energy expenditure (kcal/min) was greater for the post-MI group compared with controls (F(2,5)=11.22, p<0.001). Throughout the MBWT, post-MI group worked at a higher %AT/MET than controls (F(2,196)=211.76, p<0.01). Body composition did not strongly influence %AT/MET, parameters of VO2, METs or RPE.

CONCLUSION

During the MBWT, post-MI men worked more anaerobically per MET (%AT/MET) than controls. Therefore, current METs based on non-cardiac individuals appear unsuitable in determining the full metabolic load of the exercise intensity for cardiac patients during the MBWT.

Appropriateness of the metabolic equivalent (MET) as an estimate of exercise intensity for post-myocardial infarction patients

AIMS

To explore: (1) whether during exercise metabolic equivalents (METs) appropriately indicate the intensity and/or metabolic cost for post-myocardial infarction (MI) males and (2) whether post-exercise VO2 parameters provide insight into the intensity and/or metabolic cost of the prior exercise.

METHODS

15 male phase-IV post-MIs (64.4±6.5 years) and 16 apparently healthy males (63.0±6.4 years) participated. Participants performed a graded cycle ergometer test (CET) of 50, 75 and 100 W, followed by 10 min active recovery (at 50 W) and 22 min seated recovery. Participants' heart rate (HR, bpm), expired air parameters and ratings of perceived exertion (exercise only) were measured.

RESULTS

General linear model analysis showed throughout significantly lower HR values in post-MI participants that were related to β-blocker medication (F(2,5)=18.47, p<0.01), with significantly higher VCO2/VO2 (F(2,5)=11.25, p<0.001) and gross kcals/LO2/min (F(2,5)=11.25, p<0.001). Analysis comparing lines of regression showed, during the CET: post-MI participants worked at higher percentage of their anaerobic threshold (%AT)/MET than controls (F(2,90)=18.98, p<0.001), as well as during active recovery (100-50 W) (F(2,56)=20.81, p<0.001); during seated recovery: GLM analysis showed significantly higher values of VCO2/VO2 for post-MI participants compared with controls (F(2,3)=21.48, p=0.001) as well as gross kcals/LO2/min (F(2,3)=21.48, p=0.001).

CONCLUSION

Since METs take no consideration of any anaerobic component, they failed to reflect the significantly greater anaerobic contribution during exercise per MET for phase-IV post-MI patients. Given the anaerobic component will be greater for those with more severe forms of cardiac disease, current METs should be used with caution when determining exercise intensity in any patient with cardiac disease.

Effect of Yoga Practice on Levels of Inflammatory Markers After Moderate and Strenuous Exercise

BACKGROUND AND OBJECTIVES

To evaluate the effect of yoga practice and exercise challenge on Tumour Necrosis Factor alpha (TNF-α), Interleukin-6 (IL-6) levels and lipid profile.

MATERIALS AND METHODS

Two hundred and eighteen subjects participated in the study. One hundred and nine volunteers (51 males and 58 females) in the age group of 20 to 60 years, who practiced yoga regularly for over five years for a period of one hour daily, performed a bout of moderate exercise and a bout of strenuous exercise as per Standardized Shuttle Walk test protocol. Anthropometrically matched, age matched and gender matched subjects, who did not practice yoga (non-yoga group) were chosen as controls (non-yoga, n=109). The non-yoga group also performed similar exercises. The blood samples of both the groups were collected before and after the exercises. TNF-α and IL-6 was analysed before and after the exercise by Sandwich ELISA (Enzyme Linked Immunosorbent Assay).

RESULTS

Resting plasma TNF-α concentration was significantly higher in non-yoga group when compared to yoga group (p<0.05). There was an increase in TNF-α levels in both the groups in response to strenuous exercise. There was no gender difference in TNF-α and IL-6 levels before and after exercise in yoga and non-yoga groups.

CONCLUSION

Regular practice of yoga lowers basal TNF-α and IL-6 levels. It also reduces the extent of increase of TNF-α and IL-6 to a physical challenge of moderate exercise and strenuous exercise. There is no significant gender difference in the TNF-α and IL-6 levels. Regular practice of yoga can protect the individual against inflammatory diseases by favourably altering pro-inflammatory cytokine levels.

Pilot investigation of the oxygen demands and metabolic cost of incremental shuttle walking and treadmill walking in patients with cardiovascular disease

OBJECTIVE

To determine if the metabolic cost of the incremental shuttle-walking test protocol is the same as treadmill walking or predicted values of walking-speed equations.

SETTING

Primary care (community-based cardiac rehabilitation).

PARTICIPANTS

Eight Caucasian cardiac rehabilitation patients (7 males) with a mean age of 67±5.2 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Oxygen consumption, metabolic power and energy cost of walking during treadmill and shuttle walking performed in a balanced order with 1 week between trials.

RESULTS

Average overall energy cost per metre was higher during treadmill walking (3.22±0.55 J kg/m) than during shuttle walking (3.00±0.41 J kg/m). There were significant post hoc effects at 0.67 m/s (p<0.004) and 0.84 m/s (p<0.001), where the energy cost of treadmill walking was significantly higher than that of shuttle walking. This pattern was reversed at walking speeds 1.52 m/s (p<0.042) and 1.69 m/s (p<0.007) where shuttle walking had a greater energy cost per metre than treadmill walking. At all walking speeds, the energy cost of shuttle walking was higher than that predicted using the American College of Sports Medicine walking equations.

CONCLUSIONS

The energetic demands of shuttle walking were fundamentally different from those of treadmill walking and should not be directly compared. We warn against estimating the metabolic cost of the incremental shuttle-walking test using the current walking-speed equations.