This study aimed to determine whether aerobic training could reduce lipid peroxidation and inflammation at rest and after maximal exhaustive exercise in overweight/obese adolescent girls. Thirty-nine adolescent girls (14-19 years old) were classified as nonobese or overweight/obese and then randomly assigned to either the nontrained or trained group (12-week multivariate aerobic training program). Measurements at the beginning of the experiment and at 3 months consisted of body composition, aerobic fitness (VO2peak) and the following blood assays: pre- and postexercise lipid peroxidation (15F2a-isoprostanes [F2-Isop], lipid hydroperoxide [ROOH], oxidized LDL [ox-LDL]) and inflammation (myeloperoxidase [MPO]) markers. In the overweight/obese group, the training program significantly increased their fat-free mass (FFM) and decreased their percentage of fat mass (%FM) and hip circumference but did not modify their VO2peak. Conversely, in the nontrained overweight/obese group, weight and %FM increased, and VO2peak decreased, during the same period. Training also prevented exercise-induced lipid peroxidation and/or inflammation in overweight/obese girls (F2-Isop, ROOH, ox-LDL, MPO). In addition, in the trained overweight/obese group, exercise-induced changes in ROOH, ox-LDL and F2-Isop were correlated with improvements in anthropometric parameters (waist-to-hip ratio, %FM and FFM). In conclusion aerobic training increased tolerance to exercise-induced oxidative stress in overweight/obese adolescent girls partly as a result of improved body composition.
Hala Youssef, Carole Groussard, Sophie Lemoine-Morel, Christophe Jacob, Elie Moussa, Abdallah Fazah, Jean-Claude Pineau, Joel Pincemail, Josiane Cillard and Arlette Delamarche
Elizabeth F. Teel, Stephen W. Marshall, L. Gregory Appelbaum, Claudio L. Battaglini, Kevin A. Carneiro, Kevin M. Guskiewicz, Johna K. Register-Mihalik and Jason P. Mihalik
without access to athletic trainers. The purpose of this phase 1 clinical trial was to establish the safety, feasibility, and adherence of an aerobic training program in healthy, recreationally active university students. We hypothesized that ACTIVE training would be safe and feasible in this cohort and
Karla A. Kubitz and Daniel M. Landers
This study examined the effects of an 8-week aerobic training program on cardiovascular responses to mental stress. Dependent variables included electrocardiographic activity, blood pressure, electroencephalographic (EEG) activity, state anxiety, and state anger. Quantification of indicators of sympathetic, parasympathetic, and central nervous system activity (i.e., respiratory sinus arrhythmia, T-wave amplitude, and EEG activity, respectively) allowed examination of possible underlying mechanisms. Subjects (n = 24) were randomly assigned to experimental (training) and control (no training) conditions. Pre- and posttesting examined cardiorespiratory fitness and responses to mental stress (i.e., Stroop and mental arithmetic tasks). MANOVAs identified a significant effect on cardiorespiratory fitness, heart rate, respiratory sinus arrhythmia, and EEG alpha laterality. The results appear consistent with the hypothesis that enhanced parasympathetic nervous system activity and decreased central nervous system laterality serve as mechanisms underlying certain aerobic training effects.
Dale I. Lovell, Ross Cuneo and Greg C. Gass
This study examined the effect of aerobic training on leg strength, power, and muscle mass in previously sedentary, healthy older men (70–80 yr). Training consisted of 30–45 min of cycle ergometry at 50–70% maximal oxygen consumption (VO2max), 3 times weekly for 16 wk, then 4 wk detraining, or assignment to a nontraining control group (n = 12 both groups). Training increased leg strength, leg power, upper leg muscle mass, and VO2max above pretraining values (21%, 12%, 4%, and 15%, respectively; p < .05). However, all gains were lost after detraining, except for some gain in VO2max. This suggests that cycle ergometry is sufficient stimulus to improve neuromuscular function in older men, but gains are quickly lost with detraining. For the older population cycle ergometry provides the means to not only increase aerobic fitness but also increase leg strength and power and upper leg muscle mass. However, during periods of inactivity neuromuscular gains are quickly lost.
Yara Fidelix, Mara C. Lofrano-Prado, Leonardo S. Fortes, James O. Hill, Ann E. Caldwell, João P. Botero and Wagner L. do Prado
Intervention The intervention consisted of clinical, nutritional, and psychological counseling and supervised aerobic training for 24 weeks, as previously described. 17 , 18 Clinical Counseling Medical follow-up was performed once a month by an endocrinologist. The session included a physical examination to
Khaled Trabelsi, Kais el Abed, Stephen R. Stannard, Kamel Jammoussi, Khaled M. Zeghal and Ahmed Hakim
The aim of this study was to evaluate the effects of aerobic training in a fasted versus a fed state during Ramadan on body composition and metabolic parameters in physically active men. Nineteen men were allocated to 2 groups: 10 practicing aerobic training in a fasted state (FAST) and 9 training in an acutely fed state (FED) during Ramadan. All subjects visited the laboratory for a total of 4 sessions on the following occasions: 3 days before Ramadan (Bef-R), the 15th day of Ramadan; the 29th day of Ramadan (End-R), and 21 days after Ramadan. During each session, subjects underwent anthropometric measurement, completed a dietary questionnaire, and provided fasting blood and urine samples. Body weight decreased in FAST and FED by 1.9% (p < .001) and 2.6% (p = .046), respectively. Body fat percentage decreased only in FAST by 6.2% (p = .016). FAST experienced an increase in the following parameters from Bef-R to End-R: urine specific gravity (0.64%, p = .012), urea (8.7%, p < .001), creatinine (7.5%, p < .001), uric acid (12.7%, p < .001), sodium (1.9%, p = .003), chloride (2.6%, p < .001), and high-density lipoprotein cholesterol (27.3%, p < .001). Of these parameters, only creatinine increased (5.8%, p = .004) in FED. Creatinine clearance values of FAST decreased by 8.9% (p < .001) and by 7.6% in FED (p = .01) from Bef-R to End-R. The authors conclude that aerobic training in a fasted state lowers body weight and body fat percentage. In contrast, fed aerobic training decreases only body weight. In addition, Ramadan fasting induced change in some metabolic parameters in FAST, but these changes were absent in FED.
Katya Vargas-Ortiz, Victoriano Perez-Vazquez, Francisco J. Diaz-Cisneros, Arturo Figueroa, Lizbeth M. Jiménez-Flores, Gustavo Rodriguez-DelaRosa and Maciste H. Macias
Sirtuin 3 enzyme (SIRT3) is involved in the regulation of mitochondrial energy homeostasis by activating Peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α). Murine models have shown that the protein SIRT3 was modified by exercise and diet, however, the effect of exercise without diet in humans has not been examined. Propose of this paper was to analyze the effect of aerobic training on SIRT3 and PGC-1α in skeletal muscle of overweight adolescents without change in caloric intake. Fourteen overweight or obese male adolescents (15.5 ± 0.8 years) trained 3 days-week/50 min x session, at 70-80% of maximal heart rate for 12 weeks. Anthropometrics and skeletal muscle biopsies from the vastus lateralis were taken before and after the exercise program to measure adiposity, SIRT3, and PGC-1α proteins. Peak aerobic capacity (VO2peak) was estimated before and after training. The participants did not change their eating habits during the intervention. SIRT3 (1.05 ± 0.11 vs. 1.25 ± 0.14 AU, p = .014) and PGC-1a (1.06 ± 0.15 Vs 1.39 ± 0.20 AU, p = .009) increased. Fat percentage and waist circumference decreased (p < .05). VO2peak increased after training (p < .001). There was a significant association between SIRT3 and PGC-1α after training program. These data suggest that aerobic training increased SIRT3 and PGC-1a expression levels in sedentary, overweight, or obese adolescents.
Renato A.C. Caritá, Camila C. Greco and Benedito S. Denadai
Prior high-intensity exercise can improve exercise performance during severe-intensity exercise. These positive alterations have been attributed, at least in part, to enhancement of overall oxygen-uptake (VO2) kinetics.
To determine the effects of prior heavy-intensity exercise on VO2 kinetics and short-term high-intensity exercise performance in individuals with different aerobic-training statuses.
Fifteen active subjects (UT; VO2max = 43.8 ± 6.3 mL · kg−1 · min−1) and 10 well-trained endurance cyclists (T; VO2max = 66.7 ± 6.7 mL · kg−1 · min−1) performed the following protocols: an incremental test to determine lactate threshold and VO2max, 4 maximal constant-load tests to estimate critical power, and two 3-min bouts of cycle exercise, involving 2 min of constant-work-rate exercise at severe intensity followed by a 1-min all-out sprint test. This trial was performed without prior intervention and 10 min after prior heavy-intensity exercise (ie, 6 min at 90% critical power).
The mean response time of VO2 was shortened after prior exercise for both UT (30.7 ± 9.2 vs 24.1 ± 7.2 s) and T (31.8 ± 5.2 vs 25.4 ± 4.3 s), but no group-by-condition interaction was detected. The end-sprint performance (ie, mean power output) was improved in both groups (UT ~4.7%, T ~2.0%; P < .05) by prior exercise.
The effect of prior heavy-intensity exercise on overall VO2 kinetics and short-term high-intensity exercise performance is independent of aerobic-training status.
Francisco J. Ordonez, Gabriel Fornieles-Gonzalez, Alejandra Camacho, Miguel A. Rosety, Ignacio Rosety, Antonio J. Diaz and Manuel Rosety-Rodriguez
Recent studies have reported that obese young people with Down syndrome suffer from low-grade systemic inflammation. Whereas this condition may be improved in the general population by regular exercise, the problem has received no attention in the case of people with intellectual disability. Therefore, the authors’ aim was to assess the influence of aerobic training on plasma adipokines in obese women with Down syndrome. Twenty obese young women with Down syndrome volunteered for this study, 11 of whom were randomly assigned to a 10-wk aerobic-training program. They attended 3 sessions/wk, which consisted of warm-up exercises followed by the main activity on a treadmill (30–40 min) at a work intensity of 55–65% of peak heart rate and ended with a cooling-down period. The control group included 9 women with Down syndrome matched for age, sex, and body-mass index. Fat-mass percentage and distribution were measured, and plasma adipokine levels (leptin and adiponectin) were assessed. In addition, each participant performed a maximal graded continuous treadmill exercise test. These parameters were assessed pre- and postintervention. Aerobic training produced a significant increase in participants’ maximal oxygen uptake (20.2 ± 5.8 vs.23.7 ± 6.3 ml · kg−1 · min−1; p < .001), and plasma leptin levels were significantly reduced in the intervention group (54.2 ± 6.7 vs.45.7 ± 6.1 ng/ml; p = .026). Further significant correlations between plasma leptin and indices of obesity were found. In contrast, no significant changes were found in adiponectin levels (p > .05). None of the tested parameters changed in the control group. In conclusion, a 10-week training program reduced leptin levels in obese young women with Down syndrome.
Rudolph G. Villani, Jenelle Gannon, Megan Self and Peter A. Rich
L-Carnitine (L-C) transports fatty acids into mitochondria for oxidation and is marketed as a weight loss supplement. In a double-blind investigation to test the weight loss efficacy of L-C, 36 moderately overweight premenopausal women were pair matched on Body Mass Index (BMI) and randomly assigned to two groups (N = 18). For 8 weeks the L-C group ingested 2 g twice daily of L-C, while the placebo (P) group ingested the same amount of lactose. All subjects walked for 30 min (60—70% maximum heart rate) 4 days/ week. Body composition, resting energy expenditure (REE) and substrate utilization were estimated before and after treatment. For the subjects who completed the study (15 P, 13 L-C), no significant changes in mean total body mass (TBM), fat mass FM, and resting lipid utilization occurred over time, nor were there any significant differences between groups for any variable. Conversely REE increased significantly for all subjects, but no between group differences existed. Five of the L-C group experienced nausea or diarrhea and consequently did not complete the study. Eight weeks of L-C ingestion and walking did not significantly alter the TBM or FM of overweight women, thereby casting doubt on the efficacy of L-C supplementation for weight loss.