Body Mass Increment Research Articles

Effects of calcium on the structure of intestinal microbiota in ovariectomized rats

To study the effect of calcium content on bone mineral density and intestinal microbiota in ovariectomized rats. A total of 30 Wistar rats were randomly divided into 3 groups, namely the sham operation group, the model group and the calcium carbonate supplement group. Postmenopausal osteoporosis rats were established by ovariectomy(OVX). After the first week of modeling, each group was intragastric separately. The calcium carbonate solution was given to the calcium carbonate supplement group, and the same amount of sterile water was given to the other two groups. The animals were executed at the end of the 12 weeks. Left femur was taken and bone mineral density(BMD) was detected by dual-energy X-ray absorptiometry. The total DNA of fecal samples was aseptically extracted and the Illumina Miseq platform was to carry out high-throughput sequencing. Compared with the sham operation group, the body mass increment of rats in the model group was significantly increased, the level of BMD was significantly reduced(P<0. 05), the intestinal microbiota diversity was not significantly changed, the Firmicutes abundance was decreased, and the Bacteroidetes abundance was increased. Compared with the model group, the body mass increment of rats in the calcium carbonate supplementation group was significantly reduced and BMD was significantly increased(P<0. 05). There was no significant change in the intestinal microbiota diversity, Firmicutes were increased, and Bacteroidetes were decreased. Calcium supplementation can improve bone mineral density and inhibit the increase of body mass during the experiment period, and its mechanism may be related to regulating the structure of intestinal microbiota.

Evolution of bone mineral density in patients with idiopathic hypercalciuria: a 20-year longitudinal study.

Several recent studies reported bone mineral density (BMD) reduction in pediatric patients with idiopathic hypercalciuria (IH). This longitudinal study aimed to evaluate BMD evolution in IH patients through three bone densitometry studies conducted over 20years on average. A second objective was to evaluate urine calcium and citrate excretion during this period. Case notes of 34 patients diagnosed with IH at age 7.9 ± 3, alongside results of two bone densitometry studies, performed at 10.5 ± 2.7 (BMD1) and 14.5 ± 2.7 (BMD2) years of age, were reviewed. Patients underwent a third densitometry study in adulthood (BMD3) aged 28.3 ± 2.9. Mean follow-up duration (time-lapse between BMD1 and BMD3) was 17.7 ± 1.4years. Statistically significant differences were found between z-BMD3 (- 0.85 ± 1.10) and z-BMD1 (- 1.47 ± 0.99) (P = 0.001) as well as between z-BMD3 and z-BMD2 (- 1.33 ± 1.20) (P = 0.016). At the end of follow-up, z-BMD3 was superior to z-BMD2 in 23 adult patients (67.6%) and lower in 11 patients (5M, 6F; 32.3%). Both men and women showed increased bone mass over time, although such increases were significant only for women. The gradual decrease observed in calcium/creatinine and citrate/creatinine ratios could be related to improvement in osteoblastic activity and especially reduction in osteoclastic activity. In patients with IH, BMD improves, which may be related especially to female sex, increment of body mass, and reduction in bone resorption. Upon reaching adulthood, urine calcium and citrate excretion tend to decrease so lithogenic risk still remains. The cause of the latter is unknown, although it likely relates to changes in bone activity.

Effects of flower volatiles from two liana species on spontaneous behavior of mice

Flowering landscape plants release various fragrances which will have different effects on human body. In this study, mice were used as a biological model to investigate the effects of wisteria and rose (two popular climbing ornamentals) fragrances on spontaneous behavior. The purpose was to provide a useful reference for the management of urban vegetation. The volatiles released by Wisteria sinensis flowers were mainly linalool and 2-nonanone, and those of Rosa multiflora were geranyl acetate and phenylethyl acetate. Mouse behavior in the open field test suggested that volatiles enhanced appetite (briefly increasing the daily increment in body mass and food intake assimilation rate). In the tests, data were collected on the total distance covered by the mice, the distance covered in the central grid, and the time spent in the central grid. Taking the data collectively, a particular concentration of W. sinensis volatiles kept the mice in a stable state, whereas a high concentration of R. multiflora volatiles enhanced the exploratory and cognitive abilities of the mice. No negative effects of volatiles were found on mouse organs, showing that wisteria and rose plants could be used safely in urban areas. However, a high concentration of volatiles (> 8 Kg·M−3), as seen in the blooming period of wisteria, would cause slight discomfort. Therefore, in construction of urban vegetation, allocation proportions of tree species and places of plantation should be considered, in order to fully take advantage of health and ecological benefits of aromatic species and to create a more favorable urban environment.

Effects of a moderate-to-high intensity resistance circuit training on fat mass, functional capacity, muscular strength, and quality of life in elderly: A randomized controlled trial

Physical exercise is considered an important intervention for promoting well-being and healthy aging. The objective was to determine the effects of moderate-to-high intensity resistance circuit training on different parameters of body composition, functional autonomy, muscular strength and quality of life in elderly. A randomized controlled trial was conducted. A total of 45 subjects (27 females, 18 males) aged between 65–75 years old from Murcia (Spain) were divided by sex, and randomly to experimental group (n = 33, mean age 69 ± 3.2 years old) receiving 12 weeks of moderate-to-high intensity resistance circuit training and control group (n = 33, mean age 70 ± 4.1 years old) receiving no exercise intervention. Intra-group comparison, the experimental group showed a significant increment of lean body mass in women and men, which also presented a decrease of fat mass. Both sex presented a significant improve in functional autonomy, and significately higher values of muscular strength. But no changes were observed regarding quality of life in these groups. The control group did not show any differences pre and post-intervention in women, but in men presented an increment of body mass index and total weight post-intervention. No changes were showed in the other variables. Similar results were founded at inter-group comparison. The moderate-to-high intensity resistance circuit training showed increase in total lean body mass, improvements in functional capacity and significantly increase in upper and lower muscular strength in women and men. Progressive resistance circuit training should be promoted for the elderly as it has the potential to improve physical performance, thereby prolonging healthy independent aging.

Does Concurrent Training Intensity Distribution Matter?

Varela-Sanz, A, Tuimil, JL, Abreu, L, and Boullosa, DA. Does concurrent training intensity distribution matter? J Strength Cond Res 31(1): 181-195, 2017-Previous research has demonstrated the influence of intensity distribution on endurance training adaptations. However, no study has addressed the influence of intensity distribution on the effectiveness of concurrent training (CT). The main objective of this study was to compare the effects of 2 CT programs with different training intensity distribution and externally equated loads on physical fitness. Thirty-one sport science students volunteered and were evaluated for resting heart rate variability (HRV), countermovement jump, bench press, half squat, and maximum aerobic speed (MAS). All were randomly distributed into either a traditional-based training group (TT; n = 11; 65-75% of MAS, combined with 10-12 repetition maximum [RM]), polarized training group (PT; n = 10; 35-40% and 120% of MAS, combined with 5RM and 15RM), or control group (CG; n = 10). After 8 weeks of training (3 daysweek), TT and PT exhibited similar improvements in MAS, bench press, and half squat performances. No differences were observed between TT and PT groups for perceived loads. There were no changes in HRV for any group, although TT exhibited a reduction in resting heart rate. Compared with other groups, the PT group maintained jump capacity with an increment in body mass and body mass index without changes in body fatness. In conclusion, PT induced similar improvements in physical fitness of physically active individuals when compared with TT. However, PT produced a lower interference for jumping capacity despite an increment in body mass, whereas TT induced greater bradycardia. Extended studies with different intensity distributions should be conducted to better determine the dose-response of CT in various populations.

Factors influencing the late phase of recovery after bone mineral density loss in allogeneic stem cell transplantation survivors.

Accelerated bone mineral density loss (BMDL) occurs early after allogeneic stem cell transplantation (SCT) and is related to factors such as steroids and chronic GvHD. In order to understand the natural history of BMDL of SCT in the longer term, we evaluated a longitudinal cohort of 148 survivors with a median follow-up of 12 years (range 3-22 years). All women received hormone replacement therapy, and routine calcium/vitamin D supplementation was recommended but ∼50% of patients still had suboptimal vitamin D levels and bisphosphonates were rarely utilized. BMD significantly improved from 5 to 20+ years but the femoral neck and forearm remained vulnerable sites. Younger age, higher pretransplant body mass index (BMI) and increment in BMI post transplant were significantly associated with increased BMD and protected against osteopenia/osteoporosis. These findings support consideration of BMD loss in SCT survivors in two phases, an early phase of BMD loss (3-5 years) followed by a later phase of BMD recovery, with different protective and aggravating factors. Treatment- and transplant-related factors (such as steroids, immunosuppressives, chronic GvHD, vitamin D) are known to impact the early phase of BMD loss but age and BMI are more influential in the late phase of BMD recovery.

The insulin-signaling pathway of the pancreatic islet is impaired in adult mice offspring of mothers fed a high-fat diet

ObjectiveMothers fed a high-fat (HF) diet can cause different adverse alterations in their offspring. The study aimed to verify the pancreatic islet structure and insulin-signaling pathway in adulthood of offspring of mothers fed a HF diet during the pregnancy. MethodsFemale mice (mothers) were randomly assigned to receive either standard chow (Mo-SC) or a HF diet (Mo-HF) ad libitum. After 2 mo on the experimental diets, 3-mo-old female mice were mated with male C57 BL/6 mice that were fed a SC diet. The male offspring was evaluated at 6 mo old. ResultsAt 6 mo of age, Mo-HF offspring had an increment in body mass and adiposity, hypercholesterolemia, and hypertriacylglycerolemia, higher levels of insulin, and leptin with a concomitant decrease in adiponectin levels. In the islet, we observed an alteration in the structure characterized by the migration of some alpha cells from the edge to the core of the islet in association with an increase in the masses of the islet, beta cell, and alpha cell, featuring a pancreatic islet remodeling. Additionally, the Mo-HF offspring demonstrated a decrease in IRS1, PI3 k p-Akt, Pd-1, and Glut2 protein expressions compared to Mo-SC offspring. However, an increase was observed in FOXO1 and insulin protein expressions in Mo-HF offspring compared to Mo-SC offspring. ConclusionThe present study demonstrated that a maternal HF diet is responsible for remodeling the islet structure coupled with an adverse carbohydrate metabolism and impairment of the insulin-signaling pathway in adult male mice offspring.

Reproductive parameters of tropical lesser noddies respond to local variations in oceanographic conditions and weather

Most attempts to link seabirds and climate/oceanographic effects have concerned the Atlantic and Pacific Oceans with comparatively few studies in the tropical Indian Ocean. This paper examines the reproductive response of the lesser noddy Anous tenuirostris to temporal fluctuations in oceanographic and climatic conditions using 8 years of monitoring data from Aride Island (Seychelles), tropical Western Indian Ocean. We tested the hypothesis that breeding parameters (mean hatching date, mean egg size, hatching and fledging successes) and chick growth are influenced by local, seasonal oceanographic conditions as expressed by ocean primary productivity (surface chlorophyll-a concentrations; CC), sea surface temperature (SST) and wind speed. We also examined the relationship between lesser noddy breeding parameters and climate conditions recorded at the basin-wide scale of the Indian Ocean (Indian Ocean Dipole Mode Index, DMI). Our findings suggest that birds had a tendency to lay slightly larger eggs during breeding seasons (years) with higher CC during April–June (pre-laying, laying and incubation periods). Hatching date was positively related to SST in April–June, with the regression parameters suggesting that each 0.5 °C increase in SST meant a delay of approx.10 days in hatching date. A negative linear relationship was also apparent between hatching success and SST in June–August (hatching and chick-rearing periods), while the quadratic regression models detected a significant effect of wind speed in June–August on fledging success. Body mass increments of growing chicks averaged over 7-day periods were positively related with (2-week) lagged CC values and negatively related with (2-week) lagged SST values. No significant relationship between DMI and lesser noddy breeding parameters was found, but DMI indices were strongly correlated with local SST. Altogether, our results indicate that the reproduction of this top marine predator is dictated by fluctuations in local environmental conditions around the colony, while the effects of large-scale oceanographic processes (DMI) on our study population might be mediated by an effect on local SST.

Dynamics of morphophysiological charateristics in female water voles (Arvicola amphibius L.) during pregnancy

Pregnancy and lactation need increased energy consumption and are accompanied by morphological and physiological changes of various maternal organs and systems. In water voles, connection of female interior characteristics has been poorly studied. Under standard vivarium conditions, we evaluated morphophysiological parameters of non-reproducing females and of females at the early (1-7 days), intermediate (8-14 days), and late (15-21 days) stages of pregnancy. There were established effect of the reproductive state on mass of abdominal and brown fat, liver, adrenals, spleen and an increment of body mass (without uterus with embryos). In pregnant females, as compared with the non-pregnant ones, the blood thyroxin level was significantly lower (16.2 +/- 0.8 and 21.7 +/- 1.4 pmpl/l) and the blood testosterone level was higher (1.29 +/- 0.19 and 0.83 +/- 0.09 nmol/l). The blood glucose content fell in the end of pregnancy. Dynamics of morphophysiological parameters at the period of pregnancy reflects the compensatory body reactions providing preservation of embryos and preparation to breeding of offspring.

Population‐wide body mass increment at stopover sites is an unreliable indicator of refuelling rates in migrating waders

Estimates of refuelling rates in migrating waders are best based on intra‐seasonal recaptures of individually marked birds. This method, however, has methodological problems associated with capture effects and difficulties in attaining sufficient sample sizes. An alternative method had been proposed whereby refuelling rates are approximated by the body mass increment from the slope of the regression between body masses of all birds caught at a site and date. We investigated the appropriateness of this indicator with a simulation study in non‐synchronized migratory species (i.e. arrivals and departures of individuals at the stopover site are not synchronized). Simulation results indicated that the mass increment across the population may be used as an approximation of refuelling rate only in populations with low turnover rates (percentage of birds arriving at/departing from stopover site per day <2%) and ideally with constant numbers of staging birds. The mass increment of non‐synchronized populations with moderate or high turnover rates (higher than 5%) depends mainly on body masses of arriving birds and is not indicative of the individual rate of refuelling. The results of the simulation study were confirmed with empirical data gathered from Wood Sandpiper Tringa glareola and Common Snipe Gallinago gallinago during their autumn migration at a stopover site in Poland. The population mass increment methods considerably underestimated refuelling rate obtained from the recapture‐based approach of individual birds in both species. As a consequence, we suggest that population mass increment should not be used as an indicator of refuelling rates in non‐synchronized stopover populations of migrating waders.

Antitumor activity of gel-forming preparation prospidin on the model of Zaidela ascitic hepatoma

Using a model of transplanted Zaidela ascitic hepatoma, the antitumor activity of hydrogel of dextran phosphate (DP) was assessed for both gel-forming and injectional prospidin forms. The drug prospidin, in injectional form and in the form of hydrogels (at doses 250, 500, 750, and 1000 mg/kg), as well as dextran phosphate hydrogel (at doses of 500 and 1000 mg/kg), was administered once intraperitoneally (in a volume of 1 or 2 mL/100 g of animal body). The studies performed have shown that all medicinal forms produce inhibition of the increment of body mass in rats with Zaidela ascitic hepatoma, as well as a significant increase in their mean lifespan. The antitumor effect of all drugs is dose-dependent; i.e., with an increase in the doses of the medicinal forms of prospidin and DP hydrogel, the mean rat lifespan increases. The gel-forming prospidin form provides a more than twofold increase in the effect of antitumor activity as compared with the injectional form and prolongation of therapeutic action, as well as curing of animals in more than 60% of cases.

External changes in embryonic and larval development of Odontophrynus cordobae Martino et Sinsch, 2002 (Anura: Cycloramphidae)

We provide the first description of development for a species belonging to Odontophrynus genus by describing all external changes of embryonic and larval stages for Odontophrynus cordobae. External morphological changes through development were analyzed on specimens bred in captivity. Embryonic and larval development, from fertilization to metamorphosis, was completed in 62 days and 46 stages were defined. We split the staging series into ten developmental groups: fertilization (stages 1 and 2); segmentation (stages 3–9); gastrulation (stages 10–12); neurulation (stages 13–16); elongation (stages 17–19); external gill larva (stages 20–24); internal gill larva (stage 25); pre-metamorphosis (stages 26–41); pro-metamorphosis (stage 42); metamorphic climax (stages 43–46). Marked increases in total length were evidenced during elongation and during stage 25, when the tadpole begins to feed. Stage 25 was the longest one (8 days) and it was related to organs rearrangement, morphological progression and body mass increment typical of free life larval form. Similar studies on related species are needed to compare different developmental stages at different taxonomic levels.

Plasma levels of leptin and orexin A in the restrictive type of anorexia nervosa

Objective The aim of the study was to analyze the pattern of leptin and orexin A plasma levels in patients with the restrictive type of anorexia nervosa (AN-R), during the course of treatment. Thirty females with AN-R, aged 18.0 ± 1.6 years (mean ± SD), range of 15.5–21.0 years, were investigated before and after 2, 3, and 6 months of treatment, which included a normocaloric diet and cognitive–behavioral psychotherapy. The control group consisted of 20 age-matched, healthy control females. Results Before the therapy, both leptin and orexin A plasma levels were significantly lower than in the control group and were negatively correlated. During treatment, leptin levels increased and, after 6 months, showed a correlation with body mass index (BMI). Orexin A levels showed a further decrease during treatment, with no correlation with BMI. Conclusions The results corroborate those of other researchers showing a decrease of leptin levels in patients with AN-R and its increase with body mass increment. They may also suggest a possible relationship between leptin and orexin A plasma level patterns in such patients.

Physical state of mother at the period of pregnancy and sexual maturation of descendants-sons of the water vole (Arvicola terrestris L.)

The role of characteristics of the maternal medium (the mother's physical state at periods of pregnancy and lactation, calendar terms of birth, the number of pups, and the ratio of sexes in the litter) has been elucidated in regulation of growth and the sexual maturation of the water vole male pups. The anogenital distance was used as an indirect supravital evaluation of the mass of testicles. The physical state of females was estimated by a change of the body mass at the period of pregnancy or lactation with aid of parameters characterizing deviation of the female body mass after the end of each reproductive cycle stage from the calculated value found from the empirical regression equation. Sons of the females whose body mass increment for the period of pregnancy exceeded the expected value or was equal to it were growing faster. Results of regression analysis have shown that the the anogenital distance in the 19-week old males is dependent statistically significantly only on the physical state of the mother at the period of their embryonic development.

Biological Symptoms of Aging in Women Regarding Physical Activity and Lifestyle

Purpose. Menopause in many women is related to worse health conditions, increased diseases incidence and body mass. The purpose of this research was to investigate whether the differentiation of the involutional changes related to the climacteric period depends on women’s physical activity and selected aspects of lifestyle. The following aging indices were analyzed: age of menopause, value of blood parameters, disease incidence, BMI. Basic procedures. The research, conducted in the health care units, was based on the survey approved by the Bioethical Com­ mittee at the Jagiellonian University. The data of 896 women above the age of 40 were used in the research. Basic statistics were calculated and tests of significance of differences and correlation were applied. Main findings. There is no significant relationship between the level of physical activity, the type of work performed and the age of menopause. However, women performing white­collar work and practicing sports enter menopause last. In smokers the age of menopause lowered. Women using vegetarian diets and women with high BMI values go through menopause later. High BMI values and nicotine addiction are significantly related to the increased level of blood sugar, diabetes incidence and high blood pressure. The cholesterol level is significantly related to the age of the subjects. The percentage of increased cholesterol level is smaller in women practicing sports who have also significantly lower BMI values than those who do not go in for any sports. Conclusions. The analysis of health and aging indices confirms the highest correlation between BMI and the external factors. Moreover, regarding the specificity of hormo­ nal changes during climacterium, overweight and obese women go through menopause later. key words: aging, menopause, physical activity, lifestyle doi:10.2478/v10038­010­0023­1 2010, vol. 11 (2), 172–178 * Corresponding author. Introduction Aging is a natural result of development and reached maturity. In recent years, due to the observed increase in life expectancy in modern societies the interest in the subject of late adulthood has increased. Many publi­ cations on aging indicate genetical and physiological conditioning of this phenomenon, yet they do not ex­ clude the influence of general lifestyle frequently re­ sulting from the educational level [1–3]. In various re­ search on different aspects of aging, including the in­ fluence of external factors on the involutional changes, ambiguities which raise questions can be observed. It means that the level of knowledge on aging processes is still insufficient. Different assessment methods of the involutional processes and the human’s biological age can be distin­ guished (e.g. based on the osteological changes, the bio­ chemical composition of cells, intensity of metabolism and many others). In women’s case also age at meno­ pause is thought to be a symptom of aging and health. This research reveals that entering the menopause pe­ riod is related to worse health conditions, increased inci­ dence of vascular diseases, osteoporosis and body mass increment. Mondul et al. [4] report that menopause in older age is related to the increased risk of breast and uterine cervix cancer. On the other hand, it has been implied that women going through menopause earlier live shorter than those going through it later [5]. The purpose of this research was to investigate whether the differentiation of the involutional changes related to the climacteric period depends on women’s physical activity and selected aspects of lifestyle (type of work, nicotine addiction, diets). The analyzed aging and health indices were: age at menopause, values of physiological and biochemical parameters (blood glu­ cose and total cholesterol, blood pressure), incidence of cardiovascular diseases and osteoporosis, body mass index (BMI) values. The obtained results may be useful to create health oriented programs for women. The increased health care of mature women is more noticeable now, since a vast majority of Polish female population born in the post­war baby boom is currently passing this onto­ genesis period. Moreover, due to the fast lifestyle and

Diet and growth of chicks of the Great Cormorant, Phalacrocorax carbo, at Ramsar, northern Iran (Aves: Phalacrocoracidae)

The diet of Great Cormorant (Phalacrocorax carbo Linnaeus, 1758) chicks was studied using regurgitated fish prey in a colony at Ramsar, northern Iran, in the 2003 breeding season. The development of young was analysed in terms of body mass and wing length growth. The regurgitated prey items belong to Gobiidae, Mugilidae, Atherinidae and Clupeidae, with approximately 90% of the regurgitated prey mass belonging to Gobiidae and Mugilidae. The growth rate, expressed as body mass increment per day during the period 1–30 days, ranged from 58.7 to 112.2 g/d and was independent of age ranking and brood size. The growth rate of wings was 5.5 to 8.2 mm/d and did not vary between broods of different sizes and chicks of different ages.

Relationship between avian growth rate and immune response depends on food availability

Life history theory predicts that when resources are limited growing organisms are likely to trade an immune response for competing demands of growth. To test this we examined the effect of energy intake on body mass increments and an immune response in hand-reared sand martin (Riparia riparia) nestlings. We subjected the nestlings to three different feeding regimes, mimicking the range of food availability in the wild, and then evaluated nestlings' immune response to phytohaemagglutinin (PHA). Direction of correlation between the magnitude of PHA-induced swelling response and body mass increments depended on food availability: it was negative when food was scarce and positive when resources were plentiful. There was no significant correlation between the two traits under intermediate feeding conditions. We conclude that the relative cost of immune function in young birds depends on food availability and, therefore, may be modified by external factors such as weather conditions or hatching asynchrony.

What explains the trot–gallop transition in small mammals?

The transition from trot to gallop in quadruped mammals has been widely hypothesized to be a strategy to minimize the energetic costs of running. This view, however, has been challenged by some experimental evidence suggesting instead that this transition might be triggered by mechanical cues, and would occur when musculoskeletal stresses reach a certain critical value. All previous experiments to test those hypotheses have used relatively large species and their results, therefore, may not be applicable to small mammals. In this study we evaluated the effect of carrying loads on the locomotor energetics and gait transitions of the rodent Octodon degus running on a treadmill. Metabolic rate and cost of transport increased about 30% with a 20% increment in body mass. This increment was higher than expectations based on other mammals, where energy consumption increases in proportion to the added mass, but similar to the response of humans to loads. No abrupt change of energy consumption between gaits was observed and therefore no evidence was found to support the energetic hypothesis. The trot-gallop transition speed did not vary when subjects were experimentally loaded, suggesting that the forces applied to the musculoskeletal system do not trigger gait transition.

Running Economy in 9- to 17-Year-Old Soccer Players

Running economy (ml.kg−1.min−1) seems to improve steadily with age, both in normally active children and adolescents and in those subjected to formal training. Allometric modelling for body mass, on the other hand, provides evidence of lack of effects for maturity in submaximal VO2 uptake. PURPOSE: The purpose of this study was to investigate the influence of treadmill gradient and velocity on the relationship between maturation and running economy. We hypothesized that a smaller increase in the oxygen uptake with increasing slope in younger children would indicate that they are less economical because of body dimensions. METHODS: Forty 9 to 17-year-old soccer players participated in this study. Standard anthropometric measurements as well as skeletal age (SkA), based on radiographs of the hand and wrist bones acording to Tanner-Whitehouse III Method (TW3) were assessed. Running economy was evaluated during a submaximal test protocol with three 6 min workloads with fixed velocity and gradient: the first at 8 km/h and 0% (EC8/0), the second at 9,5 km/h and 0% (EC9.5/0) and the third at 8 km/h and 5% (EC8/5). After cluster analysis, the whole sample was divided in three groups with the SkA as criterium: Group 1 <12years; Group 2≥12, <14years; Group 3 ≥14years. Correlation coefficients between variables were calculated using Pearson's Product Moment (r). The interaction between SkA groups and workloads was analysed using two-way ANOVA with repeated measures. RESULTS: VO2 uptake (ml.kg−1.min−1) consistently decreased with body mass increment for the three submaximal workloads (p<0.05 in EC8/0 and EC8/5; p<0.01 in EC9.5/0) but was not related to SkA in any situation. Standard ratio VO2 values were negatively correlated to body mass (p<0.05) in all workloads but were not significantly different among groups, in any workload. Percent differences in VO2(ml.kg−1.min−1) from EC8/0 to EC8/5 and to EC9.5/0 were correlated (r = 0.564; p<0.01) in the whole sample but were not significantly different from each other neither did they vary between SkA based groups. Allometric modelling provided us with scaling factors of 0.838, 0.843 and 0.842 for EC8/0, EC8/5 andEC9.5/0, respectively. VO2 scaled allometric ally showed stables values with SkA (r = 0.02). CONCLUSIONS: Within this group of young soccer players, submaximal VO2 responses were explained predominantly by changes in body mass, with no additional maturity-related effects. Moreover, the variation in oxygen uptake as a consequence of increased workload either by velocity or slope increases is independent of maturation.

Comparison of body mass, food intake and plasma constituents in lean and obese Zucker rats under cold acclimation and deacclimation

Male obese and lean Zucker rats, aged 7 weeks, were maintained at 25 °C for 11 weeks, at 10 °C for 11weeks or at 25 °C for 2 weeks following exposure to 10 °C for 9 weeks. The increase in food intake during cold exposure was much smaller in obese rats than in lean rats. The suppressive effect on body mass increment by cold acclimation was more profound in obese rats. In obese rats, the concentration of plasma triglycerides and insulin was lower during cold acclimation, and improvement in carbohydrate and lipid metabolism due to cold exposure was maintained during deacclimation.