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Effects of high-intensity interval training on endothelial function, lipid profile, body composition and physical fitness in normal-weight and overweight-obese adolescents: A clinical trial.
da Silva, MR, Waclawovsky, G, Perin, L, Camboim, I, Eibel, B, Lehnen, AM
Physiology & behavior. 2020;:112728
Abstract
Endothelium-aggressive factors are associated with the development of atherosclerosis. Exercise training can either prevent or attenuate this process, but little is known about the effects of high-intensity interval training (HIIT) in adolescents. Thus, we assessed the effects of HIIT on endothelial function, lipid profile, body composition and physical fitness in normal-weight and overweight-obese adolescents. Thirty-eight participants aged 14-17 years who were physically inactive (IPAq) were divided in two groups: normal weight (NW, n = 13) and overweight-obese (OW, n = 25). Body composition, lipid profile, physical fitness and endothelial function (flow-mediated dilation, FMD) were assessed before and after undergoing the study protocol consisting of 12-week HIIT (∼15 min) + sport activities (30 min, 3×/week) + no diet. The differences were tested by GEE, Bonferroni post-hoc, p < 0.05. There were no changes in body composition after training period, but the OW group showed a reduction in waist (4.8 cm; p = 0.044) and abdominal circumference (3.7 cm; p = 0.049). We found improved physical fitness (cardiorespiratory endurance, explosive strength, abdominal muscle endurance and flexibility) in both groups. Lower endothelial function was found in the OW compared to NW (p = 0.042) at baseline. FMD increased (p < 0.001) in both groups from baseline (NW Δ4.1%; Cohen's effect size 0.64; OW Δ4.5%; Cohen's effect size 0.73) with no significant difference between the groups. In conclusion, a HIIT program even without any dietary changes can improve physical fitness and endothelial function among adolescents. These findings are clinically relevant because they support a reduction in endothelial damage that precedes the development of atherosclerosis.
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Eleven Weeks of Iron Supplementation Does Not Maintain Iron Status for an Entire Competitive Season in Elite Female Volleyball Players: A Follow-Up Study.
Mielgo-Ayuso, J, Zourdos, MC, Calleja-González, J, Córdova, A, Fernandez-Lázaro, D, Caballero-García, A
Nutrients. 2018;(10)
Abstract
BACKGROUND Even though iron supplementation can be effective, it is necessary to be cautious of toxicity and aim to do no harm, therefore, it is important to examine the length of time the benefits of iron supplementation can be maintained following its cessation. The main purpose of this study was to analyze if iron stores and strength performance were maintained in elite female volleyball players for the final 18 weeks of a competitive season following the cessation of 11 weeks of iron supplementation. METHODS Twenty-two volleyballers (age: 27.0 ± 5.6 years.) were assigned to two groups (iron treatment group-ITG, n = 11 or control gropu-CG, n = 11) at the beginning of a previous trial (T0) and ITG consumed 325mg/d of ferrous sulphate for 11 weeks (T11). Then, in the present study iron status and strength were measured again 10 (T21) and 18 weeks later (T29) after the cessation of supplementation. RESULTS At the end of the previous trial (T11), ITG maintained iron status as measured by hematological parameters (serum iron-sFE, serum ferritin-FER, transferrin saturation index-TSI, and hemogloblin-Hb), however, CG showed a decrease in these markers at T11. Further, from T0 to T11 ITG experienced greater (p < 0.05) changes in clean and jerk, power clean, and total mean strength (TMS-sum of all strength tests) than CG. In the present, follow-up investigation, there was a group-by-time interaction in favor of CG vs. ITG from T11 to T21 for FER (p = 0.028) and Hb (p = 0.042). Further, there was an increase for CG (p < 0.001) in power clean for CG from T11 (38.4 ± 1.7 kg) to T21 (41.3 ± 1.9 kg) and T29 (41.8 ± 1.7 kg), but no change for power clean in ITG (p > 0.05). A group-by-time interaction from T11 to T29 occurred in favor of CG for half-squat (p = 0.049) and TMS (p = 0.049). CONCLUSION Our findings suggest that the benefits of iron supplementation are not sustained in elite female volleyballers if supplementation is ceased for 18 weeks.
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Effectiveness of a 5-year school-based intervention programme to reduce adiposity and improve fitness and lifestyle in Indian children; the SYM-KEM study.
Bhave, S, Pandit, A, Yeravdekar, R, Madkaikar, V, Chinchwade, T, Shaikh, N, Shaikh, T, Naik, S, Marley-Zagar, E, Fall, CH
Archives of disease in childhood. 2016;(1):33-41
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Abstract
DESIGN Non-randomised non-blinded school-based intervention study. SETTING Two schools in the cities of Pune and Nasik, India. PARTICIPANTS The intervention group comprised children attending a Pune school from 7-10 years until 12-15 years of age. Two control groups comprised children of the same age attending a similar school in Nasik, and children in the Pune intervention school but aged 12-15 years at the start of the study. INTERVENTION A 5-year multi-intervention programme, covering three domains: physical activity, diet and general health, and including increased extracurricular and intracurricular physical activity sessions; daily yoga-based breathing exercises; making physical activity a 'scoring' subject; nutrition education; healthier school meals; removal of fast-food hawkers from the school environs; and health and nutrition education for teachers, pupils and families. MAIN OUTCOME MEASURES Body mass index (BMI), waist circumference, physical fitness according to simple tests of strength, flexibility and endurance; diet; and lifestyle indicators (time watching TV, studying and actively playing). RESULTS After 5 years the intervention children were fitter than controls in running, long jump, sit-up and push-up tests (p<0.05 for all). They reported spending less time sedentary (watching TV and studying), more time actively playing and eating fruit more often (p<0.05). The intervention did not reduce BMI or the prevalence of overweight/obesity, but waist circumference was lower than in the Pune controls (p=0.004). CONCLUSIONS It was possible to achieve multiple health-promoting changes in an academically competitive Indian school. These changes resulted in improved physical fitness, but had no impact on the children's BMI or on the prevalence of overweight/obesity.
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Multiple components of fitness improved among overweight and obese adolescents following a community-based lifestyle intervention.
Howie, EK, McVeigh, JA, Abbott, RA, Olds, TS, Straker, LM
Journal of sports sciences. 2016;(16):1581-7
Abstract
Fitness is an important component of health, and obese adolescents regularly have poor fitness. Unfortunately, few have assessed the impact of community-based lifestyle interventions on multiple components of fitness. The purpose of this study was to assess the impact of participation in a community-based intervention involving adolescents and parents on multiple components of fitness of obese adolescents. In a within-subject, waitlist controlled clinical trial with 12 months follow-up in Western Australia, participants (n = 56) completed multiple fitness measures at baseline, immediately prior to beginning an 8-week intervention and at 3, 6 and 12 months during a maintenance period. Performance on the shuttle walk was improved immediately post-intervention (increase of 42.8 m, 95% CI: 7.5, 78.2) and at 12 months post-intervention (increase of 44.6 m, 95% CI: 1.3, 87.8) compared with pre-intervention. Muscle performance of quadriceps and deltoids were improved post-intervention (increase of 1.1 (95% CI: 0.1, 2.1) kg · F and 1.0 (0.02, 2.1) kg · F, respectively) and all muscle performance measures were improved at 12 months following the intervention. There were no changes in waist circumference. A community-based lifestyle programme such as Curtin University's Activity, Food and Attitudes Program (CAFAP) may be a viable strategy for improving fitness in overweight adolescents.
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Influence of exercise training and eating behavior on arterial stiffness in young healthy students.
Sîrbu, E, Buzaș, R, Mihăescu, R, Suceava, I, Lighezan, D
Wiener klinische Wochenschrift. 2015;(13-14):555-60
Abstract
AIM: Increased arterial stiffness is an important risk factor for the development of cardiovascular disease. The aim of the present study was to compare arterial function and other anthropometric parameters in trained vs sedentary, healthy young students. Furthermore, the study explores the relationship between arterial stiffness and eating behavior in these students. METHODS Two groups of healthy university students were recruited for this study. The first group consisted of 10 men and 8 women (mean age: 23.27 ± 3.2 years) with an athletic predisposition. Furthermore, over the course of 6 months this group participated in 60-min training sessions designed as interval training circuits with a frequency of three to five times a week. For comparison, a group of age-matched sedentary students (5 men and 13 women; 24.27 ± 2.6 years) were recruited from the same institution. Weight, height, body mass index (BMI), as well as neck and abdominal circumferences (ABs) were recorded. Arterial tension, heart rate, arterial stiffness measurements were simultaneously determined. Lastly, all students completed a 51-item "Eating Behavior Patterns Questionnaire". RESULTS Age, weight, BMI, AB, and blood pressure were not significantly different between the two groups (p > 0.05). The moderately aerobic trained students showed a significantly lower heart rate, neck circumference, and arterial stiffness as compared with their untrained, sedentary counterparts. Additionally, pulse wave velocity (PWV) measurements were correlated to a lower weight, heart rate, blood pressure, AB, and neck circumference (p < 0.05) found in trained subjects at the end of the 6-month training period. Furthermore, the nutritional habit analysis showed that in the sedentary group, snacking, emotional eating, and cultural/lifestyle behaviors are positively correlated with PWV (p < 0.05). CONCLUSION Healthy subjects with higher PWV may benefit from consistent aerobic exercise training to improve arterial stiffness. Our eating behavior study shows that healthy eating may improve vascular function and therefore can reduce the risk of cardiovascular diseases.
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Does extensive on-water rowing increase muscular strength and endurance?
Lawton, TW, Cronin, JB, McGuigan, MR
Journal of sports sciences. 2012;(6):533-40
Abstract
The purpose of this study was to compare changes in aerobic condition, strength, and muscular endurance following 8 weeks of endurance rowing alone or in combination with weight-training. Twenty-two elite rowers were assigned to (1) rowing (n = 10, 250-270 km · week⁻¹) or (2) rowing (n = 12, 190-210 km · week⁻¹) plus four weight-training sessions each week. Pre and post mean and standardized effect-size (ES) differences in aerobic condition (watts at 4 mmol · L⁻¹) and strength (isometric pull, N), prone bench-pull (6-repetition maximum, 6-RM), 5- and 30-repetition leg-press and 60-repetition seated-arm-pull (J, performed on a dynamometer) normalized by body mass and log-transformed were analysed, after adjusting for gender. The standardized differences between groups were trivial for aerobic condition (ES [±90% CI] = 0.15; ±0.28, P = 0.37) and prone bench-pull (ES = 0.27; ±0.33, P = 0.18), although a moderate positive benefit in favour of rowing only was observed for the seated-arm-pull (ES = 0.42; ±0.4, P = 0.08). Only the weight-training group improved isometric pull (12.4 ± 8.9%, P < 0.01), 5-repetition (4.0 ± 5.7%, P < 0.01) and 30-repetition (2.4 ± 5.4%, P < 0.01) leg-press. In conclusion, while gains in aerobic condition and upper-body strength were comparable to extensive endurance rowing, weight-training led to moderately greater lower-body muscular-endurance and strength gains.
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Short-term street soccer improves fitness and cardiovascular health status of homeless men.
Randers, MB, Petersen, J, Andersen, LJ, Krustrup, BR, Hornstrup, T, Nielsen, JJ, Nordentoft, M, Krustrup, P
European journal of applied physiology. 2012;(6):2097-106
Abstract
This study examined the effect of 12 weeks of small-sided street soccer (2.2 ± 0.7 sessions/week) and fitness center training (0.5 ± 0.2 sessions/week) on physical fitness and cardiovascular health profile for homeless men. Exercise capacity, maximal oxygen uptake (VO(2max)), body composition (DXA scans), blood pressure (BP), and blood lipid profile were determined before and after the intervention period for 22 soccer-group subjects (SG) and 10 waiting list controls (CO). In addition, time-motion analyses, HR measurements, and pedometer recordings were performed during street soccer training and daily-life activities. During a 60 min 4 versus 4 street soccer session 182 ± 62 intense running bouts were performed; mean HR was 82 ± 4% HR(max) and HR was >90% HR(max) for 21 ± 12% (±SD) of total time. On a day without training the participants performed 10,733 ± 4,341 steps and HR was >80% HR(max) for 2.4 ± 4.3 min. In SG, VO(2max) was elevated (p < 0.05) from 36.7 ± 7.6 to 40.6 ± 8.6 ml/min/kg after 12 weeks and incremental cycle test performance was improved (p < 0.05) by 81 s (95% CI: 47-128 s). After 12 weeks, fat percentage (19.4 ± 8.5 to 17.5 ± 8.6%) and LDL cholesterol (3.2 ± 1.1 to 2.8 ± 0.8 mmol L(-1)) were lowered (p < 0.05) in SG. The observed changes in SG were different (p < 0.05) from CO and no intra-group changes occurred for CO (p > 0.05). BP was unaltered after 12 weeks (p > 0.05), but diastolic BP was lowered for all SG subjects with pre-values >75 mmHg (83 ± 6 to 76 ± 6 mmHg, n = 8, p < 0.05). In conclusion, the exercise intensity is high during street soccer and regular street soccer training can be used as an effective activity to promote physical fitness and cardiovascular health status for homeless men.
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Maximal and submaximal physiological responses to adaptation to deep water running.
Azevedo, LB, Lambert, MI, Zogaib, PS, Barros Neto, TL
Journal of sports sciences. 2010;(4):407-14
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Abstract
The aim of the study was to compare physiological responses between runners adapted and not adapted to deep water running at maximal intensity and the intensity equivalent to the ventilatory threshold. Seventeen runners, either adapted (n = 10) or not adapted (n = 7) to deep water running, participated in the study. Participants in both groups undertook a maximal treadmill running and deep water running graded exercise test in which cardiorespiratory variables were measured. Interactions between adaptation (adapted vs. non-adapted) and condition (treadmill running vs. deep water running) were analysed. The main effects of adaptation and condition were also analysed in isolation. Runners adapted to deep water running experienced less of a reduction in maximum oxygen consumption (VO2max) in deep water running compared with treadmill running than runners not adapted to deep water running. Maximal oxygen consumption, maximal heart rate, maximal ventilation, VO2max at the ventilatory threshold, heart rate at the ventilatory threshold, and ventilation at the ventilatory threshold were significantly higher during treadmill than deep water running. Therefore, we conclude that adaptation to deep water running reduces the difference in VO2max between the two modalities, possibly due to an increase in muscle recruitment. The results of this study support previous findings of a lower maximal and submaximal physiological response on deep water running for most of the measured parameters.
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Effects of strength training on physical function: influence of power, strength, and body composition.
Hanson, ED, Srivatsan, SR, Agrawal, S, Menon, KS, Delmonico, MJ, Wang, MQ, Hurley, BF
Journal of strength and conditioning research. 2009;(9):2627-37
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Abstract
The purpose of this study was to determine (a) the effects of strength training (ST) on physical function and (b) the influence of strength, power, muscle volume (MV), and body composition on physical function. Healthy, inactive adults (n = 50) aged 65 years and older underwent strength, power, total body composition (% fat and fat free mass [FFM]), and physical function testing before and after 22 weeks of ST. Physical function testing consisted of tasks designed to mimic common physical activities of daily living (ADL). To improve internal validity of the assessment of mid-thigh intermuscular fat, subcutaneous fat, and knee extensors MV, a 10-week unilateral ST program using the untrained leg as an internal control preceded 12 weeks of whole-body ST. Strength, power, and FFM increased significantly with ST (all p < 0.05), whereas rapid walk, 5 chair stands, and get up and go time decreased significantly with ST in the overall group (all p < 0.05). Women improved significantly in both walking test times (both p < 0.05) but not in the stair climb test, whereas men improved in the stair climb test (p < 0.05) but not in walking test times. Multiple regression analysis revealed the highest R (0.28) for the change in chair stands time, followed by stair climb and usual walk at 0.27 and 0.21, respectively. ST improves performance in functional tasks important for ADLs. Changes in strength, power, and FFM are predictors of ST-induced improvements in these tasks.
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[Effectiveness of a dietary and physical activity intervention to prevent obesity in school age children].
Kain, J, Uauy, R, Leyton, B, Cerda, R, Olivares, S, Vio, F
Revista medica de Chile. 2008;(1):22-30
Abstract
BACKGROUND With the aim of contributing to he Healthy Goal 2010 of reducing significantly the prevalence of childhood obesity we developed and implemented during 2003 and 2004, a school-based obesity prevention intervention which included nutrition education and the promotion of physical activity. AIM: To report the results of the intervention. MATERIAL AND METHODS The sample included 1760 children (1st to 7th grade) from 3 elementary public schools in Casablanca (experimental group) and 671 from a similar school located in Quillota, a neighboring city (control). Primary outcomes were body mass index (BMI) Z score, the mile and shuttle-run tests and obesity prevalence. We also compared changes in waist circumference and triceps skinfold between both groups. Effectiveness of the intervention was assessed by analyzing separately the group *age* time interaction for the first 3 outcomes (follow-up-baseline), using a mixed model of covariance and by comparing variations in obesity prevalence between both groups. RESULTS There was a significant decline in BMI Z scores in experimental schools for both genders, but greater in boys (p <0.001 versus p =0.0034 in girls), while in controls, BMI Z scores increased. Obesity prevalence declined significantly in experimental schools; from 17 to 12.3% and from 14.1 to 10.3% in boys and girls respectively, while in the control group, it remained unchanged. Also, triceps skinfold in girls from Casablanca increased significantly less than that of control girls. CONCLUSION This intervention proved that it is possible to reduce significantly the prevalence of obesity in Chilean schoolchildren attending public elementary schools.