Cardiorespiratory fitness, obesity, and functional limitation in older adults

The relationship between age related changes in strength and fitness with body size, shape and composition

Handgrip strength (HGS), cardiorespiratory fitness (CRF) and body size, shape, and composition are all related to cardiometabolic health and are associated in cross-sectional settings. Their longitudinal relationship is less clear. We used observational data from the Study of Health in Pomerania at baseline (SHIP-TREND-0; 2008-2012) and follow-up (SHIP-TREND-1; 2016-2019) with 1,214 men and 1,293 women. HGS was measured with a hand dynamometer. CRF was assessed using cardiopulmonary exercise testing. Linear regression models were adjusted appropriately. Several sensitivity analyses were performed. From baseline to follow-up (7 years) HGS decreased in men (3.5 kg) and women (0.8 kg). VO2peak lessened in men (36 ml/min) and increased in women (53 ml/min). We only found significant relations in men where a 1 l decline in VO2peak was associated with a 0.87 kg larger decrease in fat free mass and with a 1.15 kg stronger decline in body weight. All other analysis revealed non-significant findings. This longitudinal analysis suggests that age related changes in strength and CRF are not related to body size and shape but only composition (in men). A novelty of our findings are the sex-specific aspects given that strength decreased much stronger in men compared to women.

The "Aging Effect" of BMI on Cardiorespiratory Fitness: A New Insight on Functional Evaluation in Obesity

Cardiorespiratory fitness (CRF) is a strong predictor of morbidity and mortality in patients with obesity. This study investigates the CRF range and its clinical determinants in patients with obesity. Moreover, a practical proposal for CRF interpretation is provided. In this study, 542 patients (69% females) with BMI ≥ 30 kg/m2 performed an incremental cardiopulmonary exercise test (CPET). Patients had a median (IQR) age of 47.0 (6.2) years with a mean BMI of 41.7 ± 6.7 kg/m2. Normal values curves of VO2peak/kg showed a median (IQR) of 20.3 (37.6) mL/min/kg. The lower-quartile threshold of VO2peak/kg was at 17.9 mL/min/kg. Analysis of covariance revealed that VO2peak/kg inversely correlates with age and BMI with a significant age × BMI interaction effect (all p < 0.0001); as BMI class increases, CRF decreases, but a smaller age-related decline in VO2peak/kg is observed. A multivariate logistic regression demonstrated that belonging to the lower quartile of VO2peak/kg was independently determined by age (OR 2.549, 95% CI 1.205-5.392, p < 0.0001) and BMI (OR 5.864, 95% CI 2.920-11.778, p < 0.0001) but not by comorbidities. At very high BMI, the effect of age on functional capacity is lower, suggesting that BMI acts as an "aging factor" on CRF. Age and BMI, but not comorbidities, are independent determinants of low VO2peak/kg.

Eccentric resistance training with neurological conditions: A meta analysis

BACKGROUND

People with neurological conditions are exposed to muscle wasting resulting in reduced strength and endurance. Both deficiencies negatively impact gait and balance, each of which can be benefited by strengthening exercises. Unfortunately, people with neurological conditions often do not have the ability to perform traditional weight training as their endurance and strength fail to meet the minimum threshold for improvement. An alternative to traditional, full range of motion lifting is eccentric resistance training (ERT).

RESEARCH QUESTION

The current systematic review and meta-analysis sought to evaluate the efficacy of ERT against conventional therapeutic modalities or weightlifting on walking speed, Timed Up and Go (TUG), and maximum voluntary isometric contraction (MVIC) in individuals with neurological conditions.

METHODS

Web of Science, PubMed, and Academic Search Complete were searched until September 1, 2020, followed by a manual search on December 3, 2021. Publications were included if they were peer reviewed, available in English, consisted of a pre-specified neurological disorder, involved human subjects, had an eccentric and "traditional" therapy; and reported at least one of the outcome measures at both pre- and post-intervention.

RESULTS

Thirteen studies of human subjects (n = 297) and 47 standardized mean differences (SMD) were included in the multilevel model analysis. The analysis revealed a small, albeit non-significant effect on performance (TUG, MVIC, walking speed) when comparing traditional therapies and ERT (SMD: 0.136; 96; 95 % CI: -0.0002, 0.050).

SIGNIFICANCE

There appears to be no difference between ERT and traditional therapy or weightlifting on measured outcomes. In this way, ERT is as effective as traditional therapeutics and full range of motion weightlifting to improve movement in clinical populations. Practitioners working with populations with neurological conditions may consider supplementing or replacing traditional strengthening activities with ERT as clients can complete greater volumes of work with lower metabolic demand.

Are flexibility and muscle-strengthening activities associated with functional limitation?

This retrospective cohort study examined the relationship between self-reported participation in flexibility and muscular strengthening activities and the development of functional limitation (i.e., once an individual has difficulty with or becomes unable to perform activities of daily living). Data were obtained from 1318 adults (mean age 49.5 ​± ​9.7 years; 98.7% Caucasian; 14.9% female) enrolled in the Aerobics Center Longitudinal Study from 1979 to 2004 and free of functional limitation at baseline. Mail-back health surveys were used to prospectively determine incident functional limitation. Participation in muscle-strengthening and flexibility activities was assessed via self-report. Adjusted logistic regression analyses were used to determine the odds ratios (OR) and corresponding 95% confidence intervals for developing functional limitation during follow-up based on participation in general and specific categories of flexibility (‘Stretching’, ‘Calisthenics’, or ‘Exercise Class’) and muscle-strengthening activities (‘Calisthenics’, ‘Free Weights’, ‘Weight Training Machines’, or ‘Other’). Overall, 42.6% of the sample reported incident functional limitation. After adjusting for potential confounders (e.g., age, sex, cardiometabolic risk factors), those who reported performing muscle-strengthening activities in general (n ​= ​685) were at lower risk of developing functional limitation [OR ​= ​0.79 (0.63–1.00)]. In addition, the specific flexibility activities of stretching (n ​= ​491) and calisthenics (n ​= ​122) were associated with 24% and 38% decreased odds of incident functional limitation, respectively. General muscle-strengthening, stretching, and calisthenics activities are prospectively associated with decreased risk of incident functional limitation in generally healthy, middle-aged and older adults. Thus, both public health and rehabilitation programs should highlight the importance of flexibility and muscle-strengthening activities during adulthood to help preserve functional capacity.

Interactive effects of aging and aerobic capacity on energy metabolism-related metabolites of serum, skeletal muscle, and white adipose tissue

Aerobic capacity is a strong predictor of longevity. With aging, aerobic capacity decreases concomitantly with changes in whole body metabolism leading to increased disease risk. To address the role of aerobic capacity, aging, and their interaction on metabolism, we utilized rat models selectively bred for low and high intrinsic aerobic capacity (LCRs/HCRs) and compared the metabolomics of serum, muscle, and white adipose tissue (WAT) at two time points: Young rats were sacrificed at 9 months of age, and old rats were sacrificed at 21 months of age. Targeted and semi-quantitative metabolomics analysis was performed on the ultra-pressure liquid chromatography tandem mass spectrometry (UPLC-MS) platform. The effects of aerobic capacity, aging, and their interaction were studied via regression analysis. Our results showed that high aerobic capacity is associated with an accumulation of isovalerylcarnitine in muscle and serum at rest, which is likely due to more efficient leucine catabolism in muscle. With aging, several amino acids were downregulated in muscle, indicating more efficient amino acid metabolism, whereas in WAT less efficient amino acid metabolism and decreased mitochondrial β-oxidation were observed. Our results further revealed that high aerobic capacity and aging interactively affect lipid metabolism in muscle and WAT, possibly combating unfavorable aging-related changes in whole body metabolism. Our results highlight the significant role of WAT metabolism for healthy aging.

Excess body weight and gait influence energy cost of walking in older adults

PURPOSE

The objective of this investigation is to study how excess body weight influences the energy cost of walking (Cw) and determine whether overweight and obese older adults self-select stride frequency to minimize Cw.

METHODS

Using body mass index (BMI), men and women between the ages of 65 and 80 yr were separated into normal weight (NW, BMI ≤24.9 kg·m(-2), n = 13) and overweight-obese groups (OWOB, BMI ≥25.0 kg·m(-2), n = 13). Subjects walked at 0.83 m·s on an instrumented treadmill that recorded gait parameters and completed three 6-min walking trials; at a preferred stride frequency (PSF), at +10% PSF, and at -10% PSF. Cw was determined by indirect calorimetry. Repeated-measures ANOVA was used to compare groups, and associations were tested with Pearson correlations, α = 0.05.

RESULTS

OWOB had 62% greater absolute Cw (301 ± 108 vs 186 ± 104 J·m, P < 0.001) and 20% greater relative Cw(kg) (3.48 ± 0.95 vs 2.91 ± 0.94 J·kg(-1)·m(-1), P = 0.046) than NW. Although PSF was not different between OWOB and NW (P = 0.626), Cw was 8% greater in OWOB at +10% PSF (P < 0.001). At PSF, OWOB spent less time in single-limb support (33.1% ± 1.5% vs. 34.9% ± 1.6 % gait cycle, P = 0.021) and more time in double-limb support (17.5% ± 1.6% vs 15.4% ± 1.4% gait cycle, P = 0.026) than NW. In OWOB, at PSF, Cw was correlated to impulse (r = -0.57, P = 0.027) and stride frequency (r = 0.51, P = 0.046).

CONCLUSIONS

Excess body weight is associated with greater Cw in older adults, possibly contributing to reduced mobility in overweight and obese older persons.

Are there differences in quality of life, symptomatology and functional capacity among different obesity classes in women with fibromyalgia? The al-Ándalus project

Obesity may influence fibromyalgia severity. The present study aimed to examine fibromyalgia (FM) symptomatology, quality of life (QoL), and functional capacity across obesity class categories. A total sample of 208 obese FM patients and 108 obese control women were included in the study. The sample was further categorized following the international criteria for obesity classes: obesity I (BMI 30.0-34.99 kg/m(2)), obesity II (BMI 35.0-39.99 kg/m(2)), and obesity III (BMI ≥40.0 kg/m(2)). QoL was assessed by means of the Short-Form-36 Health Survey (SF-36) and FM symptomatology with the Fibromyalgia Impact Questionnaire (FIQ). Standardized field-based fitness tests were used to assess cardiorespiratory fitness, muscular strength, flexibility, agility, and balance. All the dimensions of QoL, as measured by SF-36, were worse in obese FM patients compared to the obese control group (all p < 0.001). Obese FM patients also scored worse in the entire functional capacity tests studied (all p < 0.001). Except for the higher FIQ-depression across obesity status categories (p < 0.05), no differences between obesity status groups were found in QoL and FM impact. However, upper-body muscular strength and cardiorespiratory fitness were worse across obesity class categories and pairwise comparisons showed differences mainly between obesity I and II (p < 0.05, and p < 0.01, respectively). The absence of clear differences in QoL and FM symptomatology among obesity classes suggests that just avoiding any obese status may be a useful advice for a better management of the disease. Nevertheless, upper-body muscular strength and cardiorespiratory fitness, which are important health indicators highly related to the mortality risk, were worse across obesity categories.