Similar maximal aerobic capacity but lower energy efficiency during low-to-moderate exercise in women with constitutional thinness: new results from the NUTRILEAN study.

PURPOSE: Individuals with constitutional thinness have been presented with a lower muscular energy metabolism at the cellular level but their effective aerobic capacities and exercise-related energy efficiency remains unexplored. The present study compares maximal and sub-maximal aerobic capacities between subjects with constitutional thinness and age-matched normal-weight ones. METHODS: Anthropometric measures, body composition (Dual-X-ray absorptiometry), physical activity and sedentary time (GT3x actigraphs), and maximal aerobic capacities (cycling V ˙ O 2peak test) were assessed in 18 constitutionally thin (CT-body mass index < 17.5 kg m-2) and 17 normal-weight (NW-body mass index between 20 and 25 kg m-2) women. Energy efficiency was assessed during a submaximal cycling test and a walking exercise. RESULTS: CT had a lower body mass and body mass index compared to NW. Absolute peak oxygen uptake and maximal aerobic power were lower in CT subjects compared to NW (ES: - 1.63 [- 2.40; - 0.86] and - 1.32 [- 2.05; - 0.58], p < 0.001). V ˙ O 2peak related to body mass was not different between groups. Gross and net efficiency (ES: - 0.78 [- 1.48; - 0.06], p = 0.03 and ES: - 0.73 [- 1.43; - 0.01], p = 0.05) were lower in CT compared to NW during the submaximal cycling exercise. The gross energy cost of walking related to body mass was lower in subjects with CT (ES: - 1.80 [- 2.60; - 0.97, p = 0.05), with no difference for the net one. Perceived exertion was similar between groups in responses to both submaximal exercises. CONCLUSION: Constitutionally thin women do not show impaired aerobic capacities at moderate to maximal intensities despite lower energy efficiency while cycling and walking at low-to-moderate intensities.

Constitutional thinness might be characterized by physiologically adapted and not impaired muscle function and architecture: new results from the NUTRILEAN study.

PURPOSE: While muscle mass and skeletal muscle fibers phenotype have been shown atypical in constitutional thinness (CT), force production capacities and its architectural determinants have never been explored. The present study compared muscle functionality and architecture between participants with CT and their normal-weight (NW) counterparts. METHODS: Anthropometry, body composition (Dual-X-ray Absorptiometry), physical activity/sedentary behavior (ActiGraph wGT3X-BT), ultrasound recording of the Vastus Lateralis (2D-ultrasound system), and functional capacities at maximal isometric and isokinetic voluntary contractions (MVCISO and MVCCON) during knee extension (isokinetic dynamometer chair Biodex) have been measured in 18 women with CT (body mass index < 17.5 kg/m2) and 17 NW women. RESULTS: A lower fat-free mass (ES: -1.94, 95%CI: -2.76 to -1.11, p < 0.001), a higher sedentary time, and a trend for a lower time spent at low-intensity physical activity, were observed in CT vs NW participants. While absolute MVCISO, MVCCON, rate of torque development (RTD), and torque work were all markedly lower in CT, these differences disappeared when normalized to body or muscle mass. Muscle thickness and fascicle length were found lower in CT (ES: -1.29, 95%CI: -2.03 to -0.52, p < 0.001; and ES: -0.87, 95%CI: -1.58 to -0.15, p = 0.02, respectively), while pennation angle was found similar. CONCLUSION: Despite lower absolute strength capacities observed in CT, present findings support the hypothesis of physiological adaptations to the low body and muscle mass than to some intrinsic contractile impairments. These results call for further studies exploring hypertrophy-targeted strategies in the management of CT.

Post-exercise energy replacement might lead to reduced subsequent energy intake in women with constitutional thinness: Exploratory results from the NUTRILEAN project.

While people with Constitutional Thinness (CT) declare a deep willingness to gain weight, there appetitive responses to energy balance manipulations remain unclear. The present work compares the effect of an acute exercise combined or not with an energy replacement load, on subsequent energy intake, appetite and food reward, between normal weight and women with CT. Anthropometric measurements, body composition (Dual X-ray absorptiometry-DXA) and aerobic capacity (VO2max) were assessed in 10 normal-weight (Body Mass Index-BMI): 20-25 kg/m2) and 10 C T (BMI<17.5 kg/m2) women (18-30 years). They randomly performed i) a resting session (CON); ii) an exercise session (EX); iii) an exercise session with energy replacement (EX + R). Their subsequent ad libitum intake, appetite feelings and food reward were evaluated (Leeds-Food-Preference-Questionnaire). CT showed a lower weight (p < 0,001), BMI(p < 0,001), Fat-Mass (%) (p = 0,003) and Fat-Free Mass (kg) (p < 0,001). CT showed a lower ad libitum energy intake on EX + R compared with CON (p = 0,008) and a higher Relative Energy Intake (REI) on CON compared with EX (p = 0,007) and EX + R (p < 0,001). A lower was observed during EX and EX + R compared with CON (p = 0,006,p = 0,009 respectively) in CT. No condition nor group effect was found for hunger. NW only showed a higher pre-meal fullness on EX + R compared to CON and EX (p < 0,001). Choice (p = 0,030), Explicit Liking (p = 0,016), Explicit Wanting (p = 0,004) and Implicit Wanting (p = 0,035) for taste were higher on EX + R than CON and EX. The decreased EI observed in CT when the exercise-induced energy expenditure is compensated by the ingestion of an equivalent energy load, might contribute to explain the difficulty to increase their energy balance and then induce weight gain. Further studies are needed to better understand their energy balance regulation to propose adapted weight gain strategies.

Challenges of considering both extremities of the weight status spectrum to better understand obesity: insights from the NUTRILEAN project in constitutionally thin individuals.

BACKGROUND/OBJECTIVES: While the physiology of obesity has been so extensively investigated to date, only an extremely small number of studies (less than 50) have focused on the other extremity of the weight spectrum: constitutional thinness. Yet, this important state of underweight in the absence of any eating disorders provides a mirror model of obesity that might be particularly insightful in understanding obesity. Nevertheless, important methodological and recruitment-related issues appear when it comes to this complex constitutionally thin phenotype, as experienced by our research group with the realization of the ongoing NUTRILEAN clinical trial. To face this challenge, the present paper aims at identifying, analyzing, and discussing the quality of such recruitment processes in publications about constitutional thinness. METHODS: In this order, a group of experts collectively created a new grading system to assess the level of rigour and quality achieved by each study based on different criteria. RESULTS: The main results were that (i) metabolic-related biasing criteria were poorly observed despite being crucial, (ii) recruitment processes were not detailed enough and with sufficient explicitness, and (iii) recruiting among already identified patients would be associated with both higher sample sizes and better scores of quality. CONCLUSIONS: The present work encourages investigators to adopt a high level of rigour despite the complexity and duration of recruitment processes for this specific population, and readers to pay close attention to the quality of recruitment when interpreting the data. To better understand obesity and its physiological adaptations, it seems essential not only to compare it to normal-weight conditions, but also to the other extremity of the weight status spectrum represented by constitutional thinness.

VO2max and Velocity at VO2max Play a Role in Ultradistance Trail-Running Performance.

PURPOSE: Previous research has shown that maximal oxygen uptake (VO2max) significantly influences performance in trail-running races up to 120 km but not beyond. Similarly, the influence of running economy on performance in ultratrail remains unclear. The aim of our study was, therefore, to determine the physiological predictors of performance in a 166-km trail-running race. METHODS: Thirty-three experienced trail runners visited the laboratory 4 to 8 weeks before the race to undergo physiological testing including an incremental treadmill test and strength assessments. Correlations and regression analyses were used to determine the physiological variables related to performance. RESULTS: Average finishing time was 37:33 (5:52) hours. Performance correlated significantly with VO2max (r = -.724, P < .001), velocity at VO2max (r = -.813, P < .001), lactate turn point expressed as percentage of VO2max (r = -.510, P = .018), cost of running (r = -.560, P = .008), and body fat percentage (r = .527, P = .012) but was not related to isometric strength. Regression analysis showed that velocity at VO2max predicted 65% of the variability in performance (P < .001), while a model combining VO2max and cost of running combined predicted 62% of the variability (P = .008). CONCLUSION: This is the first study to show that VO2max and velocity at VO2max are significant predictors of performance in a 166-km trail-running race. This suggests that ultratrail runners should focus on the development of these 2 qualities to optimize their race performance.

New Insights on Bone Tissue and Structural Muscle-Bone Unit in Constitutional Thinness.

While few studies pointed out low bone mineral densities in constitutionally thin women, little is known about potential explanations. The objective was to further explore bone architecture in both women and men with constitutional thinness to investigate their mechanical muscle-bone coupling (or uncoupling). Thirty constitutionally thin people and 31 normal weight controls participated in the study. Body composition, hip structural analysis, and trabecular bone score were assessed by dual-energy X-ray absorptiometry, bone architecture using high-resolution peripheral quantitative computed tomography, and muscle explorations through histological staining on muscle biopsies. Thirty-two out of the 48 indexes relative to density, geometry, texture, and architecture of bones were found significantly lower (p < 0.05) in constitutionally thin individuals compared with controls. This observation was particularly pronounced in constitutionally thin men. Bone microarchitecture was more altered in weight-supporting bone (tibia) than in non-weight-supporting (radius) bone, which might refer to a normal physiological adaptation (Frost's mechanostat theory). Yet, the heat-maps of correlations analyses showed many alterations of body weight or muscle associations with bone parameters in constitutionally thin individuals contrary to controls. Present results might support the idea of intrinsic disturbances of bone cells independently to the small muscle structure, particularly in men.

Aqua Walking as an Appropriate and Healthy Winter and Summer Physical Practice? An Exploratory Study.

(1) Background: Aqua-walking in a natural environment is a health promoting physical activity that is gaining popularity and appropriate for a variety of populations, however, to date, there is little scientific evidence supporting the efficacy and safety of this activity for older adults. The objective was to propose a preliminary exploration of psychometric and metabolic responses to an acute Aqua walking session either during winter or summer in older adults Aqua walking exercisers. (2) Methods: Heart rate, body temperature, glycemia, and blood pressure were monitored in 37 (30 women, 7 men) participants aged 52 to 83 years old in two Aqua walking sessions (water at 13 °C and 18.5 °C, respectively). Anthropometry (body weight, waist, and hip circumferences), body composition, physical activity level, sedentary time, sleep quality, quality of life, physical self-perception, and perceived health and feelings on various parameters were also assessed. (3) Results: Present results revealed a greater quality of life, physical self-perception, and perceived health in aging Aqua walking exercisers compared to those found in the literature in younger populations. None of the metabolic or psychometric measurements were found to be different between classically calibrated Aqua walking sessions performed in winter compared to summer. By contrast, there was a time effect during the sessions for body temperature (p < 0.001), SBP (p = 0.17), perceived mental and physical well-being (p = 0.006 and p < 0.001, respectively), and anxiety (p < 0.001). Leg discomfort also showed a time effect (p = 0.0009) and interaction effect (p = 0.025). (4) Conclusion: Aqua walking appears here to be an accessible practice that can be performed all year long with a range of physical and mental benefits for older adults. Future studies should investigate the metabolic responses of Aqua walking in different populations.

Reliability and Validity of the ONAPS Physical Activity Questionnaire in Assessing Physical Activity and Sedentary Behavior in French Adults.

This study was conducted to assess the validity and reliability of a new questionnaire, the ONAPS-PAQ, developed to assess physical activity (PA) and sedentary behaviors (SB) in the general population. A total of 137 healthy adults aged 18 to 69 years were included. Following completion of two physical activity questionnaires (ONAPS-PAQ and GPAQ, the Global physical activity questionnaire) to study concurrent validity, participants wore an accelerometer (UKK-RM42) for 7 days to study criterion validity. A subsample (n = 36) also completed a 7-day-interval test-retest protocol to assess its reliability. Reliability was tested by the intraclass correlation coefficient (ICC) and Kappa coefficient; concurrent and criterion validity by the Spearman correlation coefficient (ρ) and Bland-Altman plot analyses. The ONAPS-PAQ showed good reliability (ICC = 0.71-0.98; Kappa = 0.61-0.99) and concurrent validity (ρ = 0.56-0.86), but only poor criterion validity (ρ = 0.26-0.41), and wide limits of agreement. Self-reported and accelerometer-measured SB were better correlated with ONAPS-PAQ than GPAQ (0.41 vs. 0.26, respectively) and medians were comparable, whereas the GPAQ underestimated SB (SBacc = 481 (432-566), SBONAPS = 480 (360-652), SBGPAQ = 360 (240-540) min·day-1; median (q1-q3)). The ONAPS-PAQ provides good reliability and acceptable validity for the measurement of PA and SB and seems to provide a better assessment of SB than GPAQ.

Muscle Proteomic and Transcriptomic Profiling of Healthy Aging and Metabolic Syndrome in Men.

(1) Background: Aging is associated with a progressive decline in muscle mass and function. Aging is also a primary risk factor for metabolic syndrome, which further alters muscle metabolism. However, the molecular mechanisms involved remain to be clarified. Herein we performed omic profiling to decipher in muscle which dominating processes are associated with healthy aging and metabolic syndrome in old men. (2) Methods: This study included 15 healthy young, 15 healthy old, and 9 old men with metabolic syndrome. Old men were selected from a well-characterized cohort, and each vastus lateralis biopsy was used to combine global transcriptomic and proteomic analyses. (3) Results: Over-representation analysis of differentially expressed genes (ORA) and functional class scoring of pathways (FCS) indicated that healthy aging was mainly associated with upregulations of apoptosis and immune function and downregulations of glycolysis and protein catabolism. ORA and FCS indicated that with metabolic syndrome the dominating biological processes were upregulation of proteolysis and downregulation of oxidative phosphorylation. Proteomic profiling matched 586 muscle proteins between individuals. The proteome of healthy aging revealed modifications consistent with a fast-to-slow transition and downregulation of glycolysis. These transitions were reduced with metabolic syndrome, which was more associated with alterations in NADH/NAD+ shuttle and ß-oxidation. Proteomic profiling further showed that all old muscles overexpressed protein chaperones to preserve proteostasis and myofiber integrity. There was also evidence of aging-related increases in reactive oxygen species but better detoxifications of cytotoxic aldehydes and membrane protection in healthy than in metabolic syndrome muscles. (4) Conclusions: Most candidate proteins and mRNAs identified herein constitute putative muscle biomarkers of healthy aging and metabolic syndrome in old men.

Is constitutional thinness really different from anorexia nervosa? A systematic review and meta-analysis.

A growing interest in constitutional thinness has been observed in the last decades, but the publications however cover various fields of study and report equivocal results. The present work systematically reviewed any clinical trials enrolling participants with constitutional thinness and bibliographic researches were performed between December 2018 and June 2020. From a total of 1 212 records initially identified, 402 records were removed as duplicates, 381 articles were excluded based on titles or abstracts and 390 references were excluded against eligibility criteria. Thirty-nine articles were finally included in the systematic review. The results showed that constitutionally thin people seem to be underweight but not underfat and present a fat-free mass as blunted as anorexic patients, despite being a little less underweight. The meta-analysis confirmed that constitutionally thin people present normal energy intake and revealed a trend toward a higher resting metabolic rate to fat-free mass ratio which suggests a highly metabolic fat-free mass. Contrary to patients with anorexia nervosa, constitutionally thin people present normal levels of insulin-like growth factor 1, estradiol, growth hormone, follicle-stimulating hormone, and luteinizing hormone. An intermediate level of leptin between anorexic and control participants was however observed in constitutional thinness. While all the studies reported normal free triiodothyronine and cortisol levels in constitutionally thin individuals, a higher fasting free triiodothyronine level (p = 0.033) and a lower 24 h mean cortisol level (p = 0.005) were observed for the first time. Present results give robust evidence that constitutionally thin people present an atypical phenotype highly different from anorexia nervosa.