Can EVH Results Predict Post-Exercise Changes in FEV1 Following Interval and Continuous Exercise?

The eucapnic voluntary hyperpnea (EVH) challenge is used to determine the presence of exercise-induced bronchoconstriction (EIBC) by monitoring changes in forced expiratory volume in 1 s (FEV1). However, the predictability of the post-EVH decline in FEV1 on post-exercise FEV1 remains unclear. Participants completed an EVH challenge to confirm EIBC and completed a continuous exercise (CONT; n = 21), high-intensity interval exercise (HI; n = 13), and sprint interval exercise (SPRT; n = 8) sessions on separate days. FEV1 was assessed pre- and post exercise. A 1% decline in FEV1, post EVH was associated with 0.44%, 0.85%, and 0.56% declines in FEV1 post CONT, post HI, and post SPRT, respectively. The decline in FEV1 following the EVH challenge was associated with the decline in FEV1 following all exercise conditions, with the strongest association being observed following HI. These findings may have implications for exercise prescription and asthma education for recreationally active adults with EIBC.

Strength training is associated with better functional fitness and perceived healthy aging among physically active older adults: a cross-sectional analysis of the Canadian Longitudinal Study on Aging.

BACKGROUND: Regular participation in strength exercise is important to promote healthy aging. However, much of the available evidence on physical activity and older adults has focused on aerobic activity, while there is less research on the benefits of exercise that is performed specifically to strengthen muscles. AIMS: Using cross-sectional data from the Canadian Longitudinal Study on Aging, the purpose of this study was to determine if strength training is associated with better functional fitness and health among older adults who meet the minimum guidelines for aerobic physical activity. METHODS: Older adults who met guidelines for aerobic physical activity (≥ 60 years, N = 9100) completed performance-based assessments of physical function and self-reported their physical activity, perceived health, and chronic conditions. Body fat was determined using DEXA. Logistic regression analyses were used to determine whether strength training was associated with better functional fitness, body composition, and health. RESULTS: 32.5% of active older adults reported engaging in strength training 1-7 days per week. Participating in any strength training was associated with better scores on measures of balance (OR 1.17, CI 1.04, 1.32), mobility (OR 1.32, CI 1.18, 1.47), body fatness (OR 1.58, CI 1.38, 1.81), and better perceived health (OR 1.34, CI 1.19, 1.51), and healthy aging (OR 1.26, CI 1.12, 1.42). DISCUSSION: These results suggest that all older adults, even those who are active and have good mobility, may benefit from strength training. CONCLUSION: Physical activity guidelines should place a greater emphasis on strength training for older adults.

Effects of replacing sitting time with physical activity on lung function: An analysis of the Canadian Longitudinal Study on Aging.

BACKGROUND: Sitting time and physical activity may be modifiable determinants of lung function. The purpose of this study was to assess the effect that replacing various movement behaviours has on lung function among individuals with and without obstructive lung disease. DATA AND METHODS: For analysis, data were used from participants of the Canadian Longitudinal Study on Aging, recruited between 2012 and 2015. Lung function was assessed using spirometry. A modified version of the Physical Activity Scale for the Elderly was used to assess sitting time and physical activity levels. Isotemporal substitution analysis was performed to analyze the effects of replacing 30 minutes per day of one movement behaviour with another, keeping the total time constant. Analyses were run separately for individuals with an obstructive lung disease (asthma, chronic obstructive pulmonary disease, or forced expiratory volume in 1 second [FEV1] ⟨ 5th percentile lower limit of normal; n=3,398), and healthy adults (n=14,707). RESULTS: When sitting time was replaced with 30 minutes per day of any type of physical activity or sleep, an increase in percent (%) of predicted FEV1 (i.e., ß=0.65, confidence interval [CI]: 0.43, 0.88 for replacing sitting time with strenuous or strengthening activity) was observed among healthy adults. Among adults with obstructive lung disease, replacing 30 minutes per day of sitting time or sleep duration with strenuous or strengthening activity was associated with an improvement in the percent of predicted FEV1 (i.e., ß=0.98, CI: 0.13, 1.82 for replacing sleep duration with strenuous or strengthening activity). DISCUSSION: Replacing sitting time with physical activity leads to significant improvements in lung function among adults with an obstructive lung disease, as well as among adults without a respiratory disease.

Acute responses to sprint-interval and continuous exercise in adults with and without exercise-induced bronchoconstriction.

The purpose was to compare the airway response to sprint interval exercise (SIE) and continuous exercise (CE) in active adults with exercise-induced bronchoconstriction (EIBC), and to compare ventilatory and oxygen delivery responses between adults with and without EIBC. Adults with EIBC (n = 8, 22.3 ± 3.0 years) and adults without EIBC (n = 8, 22.3 ± 3.0 years) completed a SIE (4 × 30 s sprints separated by 4.5 min of active recovery) and CE (20 min at 65% peak power output) session. Lung function was assessed at baseline, during exercise, and up to 20 min post-exercise. Ventilatory parameters and tissue saturation index (TSI) were recorded continuously throughout the sessions. The decline in forced expiratory volume in 1 s was similar following SIE (-8.6 ± 12.6%) and CE (-9.0 ± 9.3%) in adults with EIBC. There were no significant differences in any of the ventilatory parameters or in TSI during SIE or CE between those with and without EIBC. These findings suggest that SIE and CE affect airway responsiveness to a similar extent. Future research using a lower intensity CE protocol in an inactive sample of adults with EIBC is needed.

Subjective responses to sprint interval exercise in adults with and without Exercise-induced bronchoconstriction.

OBJECTIVE: Little is known of the subjective response to exercise that involves short "all out" bursts of effort, separated by recovery periods (sprint interval exercise (SPRINT)) among adults with exercise-induced bronchoconstriction (EIBC). The purpose of this study was to compare subjective responses to SPRINT and moderate intensity continuous exercise (MOD) among adults with EIBC, and to compare these responses between adults with EIBC and those without EIBC. METHODS: Eight adults (22.3 ± 3.0 years) with EIBC, and eight adults (22.3 ± 3.0 years) without EIBC completed a SPRINT (4 × 30 second sprints separated by 4.5 minutes of active recovery) and MOD (20 minutes at 65% peak power output) session in random order. Self-reported affect, perceived breathlessness, and perceived exertion were recorded throughout exercise using validated scales. Enjoyment was assessed following exercise. RESULTS: Differences between SPRINT and MOD were observed such that affect and perceived breathlessness were worse during the initial stages of SPRINT than MOD; however, differences disappeared by the end of exercise. Enjoyment was similar for SPRINT and MOD in the EIBC group (SPRINT: 72.9 ± 20.0 vs. MOD: 79.5 ± 20.5, p = 0.25), and between groups for SPRINT and MOD. CONCLUSIONS: Perceived breathlessness may impact affect during the early stages of exercise among those with EIBC. Post-exercise enjoyment appears to be similar between SPRINT and MOD. Future research is needed to better understand the relationship between ventilation patterns, exercise intensity, and enjoyment of exercise among those with EIBC.

Movement behaviours are associated with lung function in middle-aged and older adults: a cross-sectional analysis of the Canadian longitudinal study on aging.

BACKGROUND: Physical activity has been shown to attenuate the age-associated decline in lung function; however, there is little research evaluating different movement behaviours as potential correlates of lung function. Modifiable determinants need to be identified, as the prevalence of chronic respiratory disease is on the rise. The purpose of this study was to investigate associations of self-reported movement behaviours (i.e., sitting time, walking, different intensities of physical activity, and strengthening activities), with lung function in middle-aged and older adults without a respiratory disease, according to their smoking history. METHODS: Data from participants of the Canadian Longitudinal Study on Aging were used for analysis (n = 16,839). Lung function was assessed using spirometry. A modified version of the Physical Activity Scale for the Elderly was used to assess sitting time and physical activity levels. Smoking status was classified as non-smoking, < 10 pack years smoking, and 10 or more pack years of smoking. The association between movement behaviours and lung function was assessed using hierarchical linear regression models with all covariates (age, sex, smoking status, body mass index, education, retirement status, and sleep duration) entered into block 1, and all movement behaviours entered into block 2. RESULTS: All movement behaviours were associated with Forced Expiratory Volume in 1 s (FEV1) and Forced Vital Capacity (FVC) % predicted in crude and adjusted models, regardless of smoking status. Sitting time was negatively associated with both FEV1%pred (ß: -0.094, CI: -0.140, - 0.047) and FVC%pred (ß: -0.087, CI: -0.128, -0.045) among those who never smoked, and strength activity was positively associated with both FEV1%pred (ß: 0.272, CI: 0.048, 0.496) and FVC%pred (ß: 0.253, CI: 0.063,0.442) among those who smoked < 10 pack years, as well as with FVC%pred among those who smoked 10 or more pack years (ß: 0.309, CI: 0.064, 0.554). CONCLUSIONS: This is the first study to assess the association of different movement behaviours with lung function among middle-aged and older adults without a respiratory disease. These findings indicate that movement behaviours are correlates of lung function, and that they may be modifiable determinants of the age-associated decline in lung function.

Physical activity and sedentary time are related to clinically relevant health outcomes among adults with obstructive lung disease.

BACKGROUND: The purpose of the current study was to determine the association between sedentary time and physical activity with clinically relevant health outcomes among adults with impaired spirometry and those with or without self-reported obstructive lung disease (asthma or COPD). METHODS: Data from participants of the Canadian Longitudinal Study on Aging were used for analysis (n = 4156). Lung function was assessed using spirometry. Adults were said to have impaired spirometry if their Forced Expiratory Volume in 1 s was <5th percentile lower limit of normal (LLN). A modified version of the Physical Activity Scale for the Elderly was used to assess sitting time and physical activity levels. Healthcare use and quality of life outcomes were assessed using self report. RESULTS: Among those with asthma, participating in strengthening activities was associated with lower odds of reporting poor perceived health (OR = 0.65, CI: 0.53, 0.79), poor perceived mental-health (OR = 0.73, CI: 0.60, 0.88), unhealthy aging (OR = 0.68, CI: 0.56, 0.83), and reporting an emergency department visit in the past 12 months (OR = 0.76, CI: 0.60, 0.95). Among those with COPD, those who reported highest weekly sedentary time had higher odds of reporting poor perceived health (OR = 2.70, CI: 1.72, 4.24), poor perceived mental-health (OR = 1.99, CI: 1.29, 3.06), and unhealthy aging (OR = 3.04, CI: 1.96, 4.72). Among those below the LLN, sitting time (OR = 2.57, CI: 1.40, 4.72) and moderate intensity physical activity (OR = 0.23, CI: 0.09, 0.63) were associated with overnight hospital stays. CONCLUSIONS: Higher physical activity levels and lower sedentary time may be associated with lower healthcare use and better quality of life. This research may have implications related to the use of physical activity for improving health outcomes and quality of life among adults with obstructive lung disease or impaired spirometry.

Sociodemographic, health-related and lifestyle correlates of physical activity in adults with current asthma.

OBJECTIVE: Regular physical activity is associated with better asthma control; however, little is known of the determinants of physical activity in a population of adults with asthma. Thus, the purpose of this study was to identify important sociodemographic, health and lifestyle correlates of physical activity among adults with asthma. METHODS: Data from adults with asthma aged 18-44 years (n = 2740) from the Canadian Community Health Survey (CCHS), 2011-2012 annual component were used for analysis. The main outcome was Daily Energy Expenditure (DEE). This variable was based on frequency and duration of leisure activities in the past 3 months. Self-reported sociodemographic (age, sex, total household income, highest education level, and ethnicity), health-related (body mass index (BMI), self-perceived health, mood disorder, anxiety disorder, and asthma symptoms/attacks, past year) and lifestyle (type of smoker, sedentary time, fruit and vegetable consumption) variables were assessed as correlates for DEE. Data were analysed using linear regressions. RESULTS: In the final model, sociodemographic correlates accounted for 4.2% of the variation in DEE. Adding health correlates increased the R2 to 12.1%. Finally, adding lifestyle correlates increased the R2 to 17.6%. CONCLUSIONS: In adults with current asthma, the main correlates of physical activity are age, total household income, BMI, self-perceived health, anxiety disorder, sedentary time, and fruit and vegetable consumption. These data are important for informing education and exercise interventions for adults with asthma. Future research is needed to determine asthma-specific correlates of physical activity.

Menthol Mouth Rinsing and Cycling Performance in Females Under Heat Stress.

PURPOSE: The effects of menthol (MEN) mouth rinse (MR) on performance, physiological, and perceptual variables in female cyclists during a 30-km independent time trial (ITT) were tested. METHODS: The participants (n = 9) cycled for 30 km in hot conditions (30°C [0.6°C], 70% [1%] relative humidity, 12 [1] km/h wind speed) on 2 test occasions: with a placebo MR and with MEN MR. Handgrip and a 5-second sprint were measured before, following the first MR, and after the ITT. Ratings of perceived exertion Borg 6 to 20, thermal sensation, and thermal pleasantness were recorded every 5 km. Core temperature and heart rate were recorded throughout. RESULTS: The ITT performance significantly improved with MEN MR by 2.3% (2.7%) relative to the placebo (62.6 [5.7] vs 64.0 [4.9] min P = .034; d = 0.85; 95% confidence interval, 0.14 to 2.8 min). The average power output was significantly higher in the MEN trial (P = .031; d = 0.87; 95% confidence interval, 0.9 to 15.0 W). No significant interaction of time and MR for handgrip (P = .581, η2 = .04) or sprint was observed (P = .365, η2 = .103). Core temperature, heart rate, ratings of perceived exertion, and thermal sensation did not significantly differ between trials at set distances (P > .05). Pleasantness significantly differed between the placebo and MEN only at 5 km, with no differences at other TT distances. CONCLUSION: These results suggest that a nonthermal cooling agent can improve 30-km ITT performance in female cyclists, although the improved performance with MEN MR is not due to altered thermal perception.