scholarly journals Lower extremity muscle size and strength and aerobic capacity decrease with caloric restriction but not with exercise-induced weight loss

2007 ◽  
Vol 102 (2) ◽  
pp. 634-640 ◽  
Author(s):  
Edward P. Weiss ◽  
Susan B. Racette ◽  
Dennis T. Villareal ◽  
Luigi Fontana ◽  
Karen Steger-May ◽  
...  
Keyword(s):  
Weight Loss ◽  
Caloric Restriction ◽  
Aerobic Capacity ◽  
Lean Mass ◽  
Muscle Volume ◽  
Muscle Size ◽  
Thigh Muscle ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Exercise Induced

Caloric restriction (CR) results in fat loss; however, it may also result in loss of muscle and thereby reduce strength and aerobic capacity (V̇o2 max). These effects may not occur with exercise-induced weight loss (EX) because of the anabolic effects of exercise on heart and skeletal muscle. We tested the hypothesis that CR reduces muscle size and strength and V̇o2 max, whereas EX preserves or improves these parameters. Healthy 50- to 60-yr-old men and women (body mass index of 23.5–29.9 kg/m2) were studied before and after 12 mo of weight loss by CR ( n = 18) or EX ( n = 16). Lean mass was assessed by dual-energy X-ray absorptiometry, thigh muscle volume by MRI, isometric and isokinetic knee flexor strength by dynamometry, and treadmill V̇o2 max by indirect calorimetry. Both interventions caused significant decreases in body weight (CR: −10.7 ± 1.4%, EX: −9.5 ± 1.5%) and lean mass (CR: −3.5 ± 0.7%, EX: −2.2 ± 0.8%), with no significant differences between groups. Significant decreases in thigh muscle volume (−6.9 ± 0.8%) and composite knee flexion strength (−7.2 ± 3%) occurred in the CR group only. Absolute V̇o2 max decreased significantly in the CR group (−6.8 ± 2.3%), whereas the EX group had significant increases in both absolute (+15.5 ± 2.4%) and relative (+28.3 ± 3.0%) V̇o2 max. These data provide evidence that muscle mass and absolute physical work capacity decrease in response to 12 mo of CR but not in response to a similar weight loss induced by exercise. These findings suggest that, during EX, the body adapts to maintain or even enhance physical performance capacity.

Muscle Strength, Size, and Composition Following 12 Months of Gender-affirming Treatment in Transgender Individuals

2019 ◽  
Vol 105 (3) ◽  
pp. e805-e813 ◽  
Author(s):  
Anna Wiik ◽  
Tommy R Lundberg ◽  
Eric Rullman ◽  
Daniel P Andersson ◽  
Mats Holmberg ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Muscle Function ◽  
Treatment Initiation ◽  
Hormone Replacement ◽  
Knee Extensor ◽  
Muscle Volume ◽  
Muscle Size ◽  
Thigh Muscle ◽  
Cross Sectional ◽  
One Year

Abstract Context As many sports are divided in male/female categories, governing bodies have formed regulations on the eligibility for transgender individuals to compete in these categories. Yet, the magnitude of change in muscle mass and strength with gender-affirming treatment remains insufficiently explored. Objective This study explored the effects of gender-affirming treatment on muscle function, size, and composition during 12 months of therapy. Design, settings, participants In this single-center observational cohort study, untrained transgender women (TW, n = 11) and transgender men (TM, n = 12), approved to start gender-affirming medical interventions, underwent assessments at baseline, 4 weeks after gonadal suppression of endogenous hormones but before hormone replacement, and 4 and 12 months after treatment initiation. Main outcome measures Knee extensor and flexor strength were assessed at all examination time points, and muscle size and radiological density (using magnetic resonance imaging and computed tomography) at baseline and 12 months after treatment initiation. Results Thigh muscle volume increased (15%) in TM, which was paralleled by increased quadriceps cross-sectional area (CSA) (15%) and radiological density (6%). In TW, the corresponding parameters decreased by –5% (muscle volume) and –4% (CSA), while density remained unaltered. The TM increased strength over the assessment period, while the TW generally maintained their strength levels. Conclusions One year of gender-affirming treatment resulted in robust increases in muscle mass and strength in TM, but modest changes in TW. These findings add new knowledge on the magnitude of changes in muscle function, size, and composition with cross-hormone therapy, which could be relevant when evaluating the transgender eligibility rules for athletic competitions.

scholarly journals Effects of Weight Loss on Lean Mass, Strength, Bone, and Aerobic Capacity

2017 ◽  
Vol 49 (1) ◽  
pp. 206-217 ◽  
Author(s):  
EDWARD P. WEISS ◽  
RICHARD C. JORDAN ◽  
ETHEL M. FRESE ◽  
STEWART G. ALBERT ◽  
DENNIS T. VILLAREAL
Keyword(s):  
Weight Loss ◽  
Aerobic Capacity ◽  
Lean Mass

The Relationship between Peak Oxygen Uptake and Physical Activity in 6- to 8-Year-Old Children

1989 ◽  
Vol 1 (2) ◽  
pp. 127-136 ◽  
Author(s):  
Juliane R. Fenster ◽  
Patty S. Freedson ◽  
Richard A. Washburn ◽  
R. Curtis Ellison
Keyword(s):  
Physical Activity ◽  
Aerobic Capacity ◽  
Large Scale ◽  
Work Capacity ◽  
Peak Oxygen Uptake ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Activity Levels ◽  
Activity Method ◽  
The Relationship

The relationship between physical activity measured using the LSI (Large Scale Integrated Activity Monitor), and questionnaire, with physical work capacity 170 (PWC 170) and aerobic capacity (peak V̇O2) was evaluated in 6- to 8-year-old children (n = 18). The mean (± SD) peak V̇O2 was 44.1 ± 5.6 ml • kg−1 • min−1. Peak V̇O2 was not significantly different for children (n = 8) who had completed two treadmill trials (45.4 vs. 43.5 ml • kg−1 • min−1; R = 0.67, p<0.05). The log LSI expressed as counts per hour (M ± SD = 2.1 ±.22 cts/hr) was the only activity method significantly related to peak V̇O2 (r = 0.59, p<0.05). The correlation between peak V̇O2 with the questionnaire was positive but nonsignificant (r = 0.20). PWC 170 was not related to peak V̇O2 (r = 0.21) or the activity variables (r = 0.12 questionnaire; r = 0.18 log LSI). When the group was divided into high and low peak V̇O2 groups (high: M = 48.8 ml • kg−1 • min−1; low: M = 39.5 ml • kg−1 • min−1), the log LSI was able to distinguish significant differences in activity levels (high: 2.23 ±. 19 cts/hr; low: 1.99±.19 cts/hr). This study suggests that activity measured with the LSI and aerobic capacity are related in this sample of 6- to 8-year-old children.

Effects of exercise combined with caloric restriction on inflammatory cytokines

2010 ◽  
Vol 35 (5) ◽  
pp. 573-582 ◽  
Author(s):  
Jennifer L. Reed ◽  
Mary Jane De Souza ◽  
Nancy I. Williams
Keyword(s):  
Weight Loss ◽  
Exercise Training ◽  
Caloric Restriction ◽  
Aerobic Capacity ◽  
Premenopausal Women ◽  
Treadmill Running ◽  
Maximal Heart Rate ◽  
Circulating Biomarkers ◽  
Tnf Α ◽  
Ifn Γ

Chronic inflammation has been implicated in the pathogenesis of several chronic diseases, such as atherosclerosis and diabetes, as well as certain types of cancers. It has been suggested that circulating biomarkers for inflammation may be modified by exercise; however, few laboratory-based studies have been conducted in nonobese premenopausal women. The purpose of this investigation was to determine the impact of a 4-month exercise training and caloric-restriction intervention with the goal of weight loss on circulating biomarkers of inflammation in sedentary premenopausal women aged 25–40 years (weight, 57 ± 2 kg). Subjects were studied for 6 consecutive menstrual cycles: 1 Screening, 1 Baseline, then 4 interventions (Interventions 1–4). Supervised aerobic training, consisting primarily of treadmill running and elliptical machine exercise, was performed 4 times per week for 40–90 min at 79% ± 0.7% of maximal heart rate. Subjects also consumed 30% fewer calories vs. baseline (1863 ± 58 to 1428 ± 53 kcal·day–1 (1 kcal = 4.186 kJ), p < 0.0001). Circulating inflammatory biomarkers, including adiponectin, high-sensitivity (hs) C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interferon-gamma (IFN-γ), and leptin, as well as body composition, aerobic capacity, and energy balance, were measured before and after the intervention. Maximal aerobic capacity increased by 8.5 ± 1.7 mL·kg–1·min–1 (p < 0.001) and body mass declined by an average of 3.7 ± 0.5 kg (p < 0.001). Significant reductions in IL-6 (0.39 ± 0.04 to 0.30 ± 0.03 pg·mL–1, p = 0.025), IFN-γ (0.58 ± 0.83 to 0.42 ± 0.64 pg·mL–1, p = 0.030), and leptin (13.18 ± 1.28 to 6.28 ± 0.71 pg·mL–1, p < 0.001) were detected in response to the intervention. No significant changes in adiponectin, hs-CRP, or TNF-α were found. Weight loss in response to exercise training and caloric restriction is effective in reducing inflammatory markers, specifically IL-6 and leptin.

scholarly journals Estimation of the aerobic capacity by step test in the workers of a tile factory in Yazd in 2017

2020 ◽  
Author(s):  
M Bahrami ◽  
F Qanai ◽  
J Mirmohammadi ◽  
M Askarishahi ◽  
A Barkhordari ◽  
...  
Keyword(s):  
Aerobic Capacity ◽  
Significant Relationship ◽  
Work Capacity ◽  
Cross Sectional Study ◽  
Step Test ◽  
Physical Work ◽  
Physical Work Capacity ◽  
Cross Sectional ◽  
Maximum Aerobic Capacity ◽  
Ceramic Workers

Introduction: Estimation of the maximum aerobic capacity to find a physiological fitness between worker and the work is of great importance. The purpose of this study was to estimate the highest aerobic capacity and physical work capacity of tile and ceramic workers. Materials and methods: In this cross-sectional study, 90 workers were randomly selected from tile and ceramic workers in Yazd. A questionnaire consisting of two parts was used as data collection tool. The first part of the questionnaire included demographic characteristics completed by the interview. In the second part, parameters including height, weight, BMI and heart rate were inserted in the questionnaire. The Queen step test was used to measure the maximum aerobic capacity. The data were analyzed by SPSS software using Mann-Whitney and Kruskal-Wallis tests and Spearman,s test. Results: The maximum aerobic capacity in tile and ceramic workers was estimated to be 3.60±.0.03 L/m. The results showed that aerobic capacity was significantly correlated with weight and body mass index. Also, there was no significant relationship between aerobic capacity, smoking and exercise, and education, but there was a significant relationship between gob title and aerobic capacity. Conclusion: Weight, BMI and type of occupation affect the aerobic capacity of workers.

Abstract P263: Acid-Base Status as a Modifier of Loss of Lean Mass During Intentional Weight Loss in Older Adults

Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Snezana Petrovic ◽  
Iris Leng ◽  
Michael P Walkup ◽  
Walter T Ambrosius ◽  
W. J Rejeski ◽  
...  
Keyword(s):  
Older Adults ◽  
Weight Loss ◽  
Caloric Restriction ◽  
Lean Mass ◽  
Protein Intake ◽  
Serum Bicarbonate ◽  
Acid Base ◽  
Lower Serum ◽  
Relative Loss ◽  
Acid Base Status

Weight loss interventions present a unique challenge in older adults: relative loss of lean mass during weight loss, if superimposed on age-related sarcopenia may increase the risk for mobility disability. Relative loss of lean mass (25-30%) during weight loss depends on the severity/duration of caloric restriction, initial body mass, and concomitant exercise training. We hypothesized that subclinical imbalances of acid-base status (reflected in lower serum bicarbonate) may also affect relative loss of lean mass during weight loss. The rationale: even subtle imbalances of acid-base status (e.g. bicarbonate <23 mmol) impact clinical outcomes in older adults such as gait speed or incidence of functional limitation, while bicarbonate supplementation reduces urinary nitrogen wasting and may improve physical function. However, data on acid-base balance and serum bicarbonate during moderate caloric restriction are lacking. We, therefore, analyzed 2 randomized, controlled weight loss trials (including moderate caloric restriction and exercise): The Diet, Exercise, and Metabolism for Older Women [DEMO; (58±5.2 y)] and Cooperative Lifestyle Program; [CLIP; (67±4.7 y)]. Serum bicarbonate was assessed as total CO 2 (in mmol) and whole body lean mass measured by dual-energy X-ray absorptiometry. The analysis showed that 48% of participants had bicarbonate <23. DEMO participants with lower serum bicarbonate at baseline lost more lean mass during the intervention (unadjusted β(SE)=0.32(0.16); p=0.04; n=92). Adjustments for age, BMI, eGFR, % weight loss, baseline, intervention group, had little effect, but adjusting for protein intake during weight loss attenuated the association (β(SE)=0.17(0.15); p=0.28.). Similarly, a change in serum bicarbonate during the trial was associated with % lean mass change, but attenuated after controlling for protein intake. This is not unexpected: protein is acid-producing and one of two major determinants of net dietary acid load; higher dietary acid load correlates with lower serum bicarbonate, in older adults. Results from the CLIP trial were remarkably similar, and consistently, baseline serum bicarbonate level was marginally predictive of baseline daily protein intake, with highest baseline serum bicarbonate having the lowest protein intake [bicarbonate: >24 (n=58); >21-24 (n=121); <21 (N=93); protein in g/kg body weight 0.7(0.4); 0.9(0.4); 0.8(0.4) respectively, p=0.057). In conclusion, our analysis suggests that higher serum bicarbonate before and during weight loss may ameliorate loss of lean mass, however, to obtain definitive answer such analysis needs to be conducted under conditions of controlled or randomized protein intake. Importantly, our findings suggest that oral bicarbonate supplementation, a simple and relatively safe intervention, may ameliorate loss of lean mass during weight loss interventions in older adults.

Effects of Exercise- or Caloric Restriction-Induced Weight Loss on Muscle Size and Strength and VO2max

2006 ◽  
Vol 38 (Suppl 1) ◽  
pp. S22
Author(s):  
Edward P. Weiss ◽  
Susan B. Racette ◽  
Dennis T. Villareal ◽  
Luigi Fontana ◽  
Karen Steger-May ◽  
...  
Keyword(s):  
Weight Loss ◽  
Caloric Restriction ◽  
Muscle Size
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