Irisin Levels Are not Associated to Resistance Training-Induced Alterations in Body Mass Composition in Older Untrained Women with and without Obesity.

OBJECTIVE: The present study aimed to determine whether Irisin levels are correlated with body composition changes following 16 weeks of resistance training (RT) in older women with and without obesity. Design, Setting, Participants, Intervention: We recruited 49 inactive women (n = 23, non-obese: < 41.0% and n = 26, obese: ≥ 41.0% of body fat) aged 61-68 years to perform 16-week of RT consisting of 10 exercises (three sets of 10 exercises, 6-12 repetitions maximum and 1-min and 30-s rest intervals between sets and exercises, respectively) with two sessions per week. MEASUREMENTS: Before and after the intervention period, blood samples were collected to determine Irisin levels and body composition (percentage body fat and fat-free mass) was measured by dual energy x-ray absorptiometry. RESULTS: Circulating Irisin displayed a decrease for the non-obese group as compared with pre-intervention and obese group (p = 0.01 and p = 0.04, respectively), with no change for the obese group (p = 0.79). In addition, fat mass displayed a significant reduction (p < 0.05) following the training period only for the obese group. Furthermore, there was no association between changes in circulating Irisin with body mass index, body fat, fat-free mass and muscle strength. There was an increase in muscle strength (p < 0.05), regardless of obesity status. CONCLUSION: The modulation of body composition and muscle strength induced by 16-week of resistance training in older women with and without obesity is not associated with changes in circulating Irisin levels.

Correlation between acute and chronic 24-hour blood pressure response to resistance training in adult women.

The purpose of the present study was to correlate the acute and chronic decrease in blood pressure (BP) following resistance training (RT). 13 normotensive women (18-49 years) completed an acute whole body RT session with 3 sets of 10 repetitions at 60% 1RM and then 8 weeks of RT as follows: 3/week, 3 sets of 8-12 repetitions maximum. Systolic (SBP) and diastolic BP (DBP) were measured up to 60 min and 24 h following RT (acute and chronic). The greatest acute decrease of SBP (108.5±7.0 mmHg) and DBP (71.5±6.4 mmHg) values over the 60-min period were reduced compared to pre-exercise (117.3±11.7 and 79.3±8.2 mmHg, respectively; p<0.05). The chronic effect on resting BP was observed only for those presenting acute post-exercise hypotension (PEH). The change in both SBP and DBP following acute RT was correlated with the chronic change in resting SBP and DBP (r>0.5; p≤0.05). The change in 24 h BP after acute RT was correlated with the chronic reduction in SBP (r=0.74) and DBP (r=0.80). The magnitude of PEH is a promising candidate for the prediction of individual BP-related training efficacy.

The acute response of apoptosis and migration to resistance exercise is protocol-dependent.

The aim of the present study was to compare the acute effects of resistance exercise (RE) designed for hypertrophy or local muscle endurance (LME) on CD4+ and CD8+ T cell apoptosis and migration. 14 untrained subjects (age 20.5±0.8 years, body mass 70.0±12.8 kg, body mass index 24.0±3.2 kg/m(2)), women (N=11) and men (N=3) completed 2 RE sessions (3 sets of 9 exercises) designed for hypertrophy at 10 repetitions maximum (RM) and LME at 60% of 10RM with 1-min rest-intervals between sets and exercises. The investigated lymphocytes were: CD4+, CD4+/CD69RA+, CD8+ and CD8+/CD69RA+ with cell surface markers annexin V and CX3CR1 analyzed by flow cytometry. Percentage of CD4+ positive for annexin V+ were higher immediately following and 24 h after the hypertrophy protocol as compared with LME, while CD4+ positive for CX3CR1 were higher immediately after and lower at the 24 h time point after LME as compared with the hypertrophy session. CD8+ lymphocytes responded similarly to the hypertrophy and LME protocols with elevations in both cellular migration and cell death immediately following and 24 h after the bouts (p≤0.05). Considering that the acute response of CD4+ lymphocytes to RE is protocol-dependent, a gradual adaptation to a hypertrophy program could minimize the effect on CD4+ lymphocytes and reduce the potential susceptibility to antigens during this timeframe. This would also be interesting for a RE program designed for LME based on the observed CD8+ lymphocyte response.

Acute effects of resistance exercise on 24-h blood pressure in middle aged overweight and obese women.

This investigation was designed to evaluate responses of blood pressure (BP) following an acute resistance exercise (RE) session. Middle-aged women (N=13) who were classified as overweight (N=8) or obese (N=5) according to body mass index (BMI) participated in the investigation. Participants were randomly submitted to a control session (30-min seated rest) and a exercise session (3 sets, 10 repetitions at 60% 1RM of exercises for the upper and lower body) with systolic (SBP), diastolic (DBP) and mean blood pressure (MBP) obtained at rest and 10, 20, 30, 40, 50, and 60-min following exercise, and through 24 h. Acute RE decreased SBP at 10, 30, and 40-min compared with pre-exercise and control (P<0.05). DBP decreased at 10 and 40-min post-exercise compared with the control trial (P<0.05). Both SBP and DBP decreased in the nighttime period (-4.2 mmHg and -4.1 mmHg, respectively) and in the overall 24 h period (-3.6 mmHg and -4.5 mmHg, respectively) following the acute RE session when compared with the control trial. These findings indicate important benefits of acute RE on BP circadian rhythm, particularly at night as well as in the morning, which are critical periods associated with increased risk for cardiovascular events.

Acute resistance training affects cell surface markers for apoptosis and migration in CD4⁺ and CD8⁺ lymphocytes.

The purpose of the present study was to examine the acute effects of resistance training (RT) on CD4⁺ and CD8⁺ T lymphocytes apoptosis (annexin V⁺) and migration (CX3CR1). Twelve subjects performed two RT sessions (3 sets of 9 exercises) with 1 min (Hyper-1) and 3 min (Hyper-3) of rest-interval length between sets and exercises. CD4⁺ and CD8⁺ cells count displayed no change following Hyper-1 and Hyper-3. There was an increase in the percentage of CD4⁺ positive for annexin V⁺ and CX3CR1⁺ immediately after and 24 h post Hyper-1. Percentage of CD4⁺ positive for annexin V⁺ increased 2 and 24 h post Hyper-3, and decreased after CXCR1⁺ for the same time-points. There was an increase in CD8⁺ positive for annexin V⁺ and CX3CR1⁺ immediately after, 2 and 24 h post Hyper-1 and Hyper-3, while no differences were found between Hyper-1 and Hyper-3. Acute RT increase the apoptosis and migration of CD4⁺ and CD8⁺ lymphocytes even 24h after exercise, with minimal effects of rest-interval length.

Resistance training and glycogen content in ovariectomized rats.

The aim of the present study was to investigate the effects of resistance training on glycogen content and muscle cross-sectional area (CSA) in ovariectomized rats. Wistar rats were divided into: sedentary; ovariectomized sedentary; resistance trained; and ovariectomized resistance trained. In the 12-week resistance training, the animals climbed a 1.1 m vertical ladder, 3 days per week, with 4-8 climbs. Cardiac, liver and muscle glycogen content was determined. After the 12-week resistance training period there was a higher hepatic and muscle glycogen content in the resistance training group compared with the other groups (p<0.01). CSA was higher in soleus for the resistance trained, ovariectomized resistance trained and sedentary compared with ovariectomized sedentary (p<0.05). Ovariectomy attenuated the increase in liver and muscle glycogen content, while soleus muscle cross-sectional area increased with resistance training, even in ovariectomized rats. Resistance training could be an important exercise to increase muscle function in situations of reduced estrogen and progesterone.

Effects of resistance training on matrix metalloproteinase-2 activity and biomechanical and physical properties of bone in ovariectomized and intact rats.

The purpose of this study was to investigate the influence of resistance training on the activity of matrix metalloproteinase (MMP)-2 and bone biomechanical properties in ovariectomized and intact rats. Forty-eight female rats were divided into two distinct groups, ovariectomized (OVX) and intact (Int), which were subdivided into three similar subgroups: sedentary, acute exercise and chronic exercise. Rats performed a resistance training for 12 weeks in which animals climbed a vertical ladder of 1.1 m with weights attached to their tails. Sessions were performed with an interval of 3, 4-9 and 8-12 days scaled dynamic movements of climbing. Biomechanical and physical analyses were performed using a universal testing machine, and MMP-2 activity analysis by zymography. Bone density (BD), mineral density (MD), maximum load and fracture load was reduced in sedentary and acute exercise OVX groups compared with the sedentary intact group (P<0.05); in contrast, chronically trained groups (OVX and Int) showed a significant increase in BD, MD and fracture load compared with all the other groups. MMP-2 activity in chronically trained groups also showed a significant increase, while the sedentary OVX group showed a decrease in MMP-2 activity compared with the intact sedentary group (P<0.05). Our results suggest that the resistance training proposed in our work was efficient in reverting the deleterious effects of ovariectomy on bone tissue, and also produced modeling effects in intact rats. On the other hand, ovariectomy reduced the activity of MMP-2 and produced deleterious effects on bone tissue, mimicking menopause intrinsically.

Acute cardiorespiratory and metabolic responses during resistance exercise in the lactate threshold intensity.

The aims were both to determine lactate and ventilatory threshold during incremental resistance training and to analyze the acute cardiorespiratory and metabolic responses during constant-load resistance exercise at lactate threshold (LT) intensity. Ten healthy men performed 2 protocols on leg press machine. The incremental test was performed to determine the lactate and ventilatory thresholds through an algorithmic adjustment method. After 48 h, a constant-load exercise at LT intensity was executed. The intensity of LT and ventilatory threshold was 27.1±3.7 and 30.3±7.9% of 1RM, respectively (P=0.142). During the constant-load resistance exercise, no significant variation was observed between set 9 and set 15 for blood lactate concentration (3.3±0.9 and 4.1±1.4 mmol x L(-1), respectively. P=0.166) and BORG scale (11.5±2.9 and 13.0±3.5, respectively, P=0.783). No significant variation was observed between set 6 and set 15 for minute ventilation (19.4±4.9 and 22.4±5.5 L x min(-1), respectively, P=0.091) and between S3 and S15 for VO2 (0.77±0.18 and 0.83±0.16 L x min(-1), respectively, P=1.0). Constant-load resistance exercise at LT intensity corresponds to a steady state of ventilatory, cardio-metabolic parameters and ratings of perceived exertion.

Overexpression of kermit/dGIPC is associated with lethality in Drosophila melanogaster

Insertional mutagenesis is an important tool for functional genomics in Drosophila melanogaster. The insertion site in the KG00562 mutant fly line has been mapped to the CG8709 (herein named DmLpin) locus and to the 3’ of kermit (also called dGIPC). This mutant line presents a high lethality rate resulting from a gain of function. To obtain some insight into the biological role of the mutated locus, we have characterized the mutation and its relation to the high mortality of the KG00562 fly line. In this mutant, we did not detect one of the DmLpin transcripts, namely DmLpinK, but we did detect an unusual 2.3-kb mRNA (LpinK-w). Further investigation revealed that the LpinK-w transcript results from an aberrant splicing between the untranslated first exon of DmLpinK and the mini-white marker gene. Lack of DmLpinK or LpinK-w expression does not contribute to lethality, since heterozygous KG00562/Def7860 animals presented lethality rates comparable to those of the wild type. In contrast, the overexpression of kermit was associated with lethality of the KG00562 fly line. Significantly higher levels of kermit were detected in the Malpighian tubules of KG00562/+ flies that presented higher lethality rates than wild-type or KG00562/Def7860 animals, in which the lethality was rescued. In agreement with a recently reported study, our data support the hypothesis that misexpression of kermit/dGIPC could interfere with Drosophila development, with further investigations being needed in this direction.

Overexpression of kermit/dGIPC is associated with lethality in Drosophila melanogaster.

Insertional mutagenesis is an important tool for functional genomics in Drosophila melanogaster. The insertion site in the KG00562 mutant fly line has been mapped to the CG8709 (herein named DmLpin) locus and to the 3' of kermit (also called dGIPC). This mutant line presents a high lethality rate resulting from a gain of function. To obtain some insight into the biological role of the mutated locus, we have characterized the mutation and its relation to the high mortality of the KG00562 fly line. In this mutant, we did not detect one of the DmLpin transcripts, namely DmLpinK, but we did detect an unusual 2.3-kb mRNA (LpinK-w). Further investigation revealed that the LpinK-w transcript results from an aberrant splicing between the untranslated first exon of DmLpinK and the mini-white marker gene. Lack of DmLpinK or LpinK-w expression does not contribute to lethality, since heterozygous KG00562/Def7860 animals presented lethality rates comparable to those of the wild type. In contrast, the overexpression of kermit was associated with lethality of the KG00562 fly line. Significantly higher levels of kermit were detected in the Malpighian tubules of KG00562/+ flies that presented higher lethality rates than wild-type or KG00562/Def7860 animals, in which the lethality was rescued. In agreement with a recently reported study, our data support the hypothesis that misexpression of kermit/dGIPC could interfere with Drosophila development, with further investigations being needed in this direction.

Menopause: highlighting the effects of resistance training.

The increase in lifespan and in the proportion of elderly women has increased the focus on menopause induced physiological alterations. These modifications are associated with the elevated risk of several pathologies such as cardiovascular disease, diabetes, obesity, hypertension, dyslipidemia, non-alcoholic fat liver disease, among others. Because of estrogen levels decline, many tissue and organs (muscular, bone, adipose tissue and liver) are affected. Additionally, body composition suffers important modifications. In this sense, there is a growing body of concern in understanding the physiological mechanisms involved and establishing strategies to prevent and reverse the effects of menopause. The hormone reposition therapy, diet and physical exercise have been recommended. Among the diverse exercise modalities, resistance training is not commonly used as a therapeutic intervention in the treatment of menopause. Thus, the aim of this review was to analyze the physiological alterations on several organs and systems induced by menopause and ovariectomy (experimental model to reproduce menopause), as well as, to study the effects of resistance training in preventing and reverting these modifications. In conclusion, resistance training promotes beneficial effects on several organs and systems, mainly, on muscular, bone and adipose tissue, allowing for a better quality of life in this population.

Well-being changes in response to 30 years of regional integration in Maya populations from Yucatan, Mexico.

Infant mortality rate (IMR), overall frequency of linear enamel hypoplasia (LEH), sexual dimorphism in LEH, age of onset of LEH, and age at menarche were used as indicators to test the hypothesis that the origin and development of the tourist industry and increased state participation on Maya subsistence agriculturists in the early 1970s had improved the well-being of the Maya. Two historical moments where inferred from the data. The first was derived from cheap and effective immunization and sanitation campaigns that reduced IMR from 143.4/1,000 live births in the early 1960s to 97.4 in the early 1970s. State participation broke the undernutrition-disease cycle enough to reduce LEH frequencies significantly (from 71.9% in individuals born before 1971 to 51.5% in those born in 1971 or after, chi(2) = 55.72; 1 df; alpha = 0.00001) and to eliminate the sex difference in LEH expression (from a 14.8% LEH difference between men and women before 1971 [Male/Female Odds Radio = 0.45, alpha significant at 0.05] to a nonsignificant 2% difference). Improvement in overall living conditions reflected in a "modern stage" infant mortality regime and an almost disappearance of LEHs, resulted from gradual improvements in living conditions that did not become apparent until the 1980s. Trends in the age at menarche are not statistically significant, probably due to methodological limitations. However, if overall living conditions continue to improve or stay as they are today, accelerations in maturation should become noticeable.