scholarly journals Teacrine Does Not Enhance Physical Performance or Training Status Over 8 Weeks

Author(s):  
Henrique Santa Capita Cerqueira ◽  
Hugo Tourinho Filho ◽  
Marcos Corrêa Junior ◽  
Carlos Eduardo Martinelli Junior

Abstract Background: Fatigue is a condition that may affect physical performance during training sessions. Consequently, this will impact training performance, moreover in the performance of the individual in long-term. Caffeine is broadly utilized to this purpose, however contains several side effects. Thus, teacrine emerges as an alternative to the use of caffeine, providing the same benefits without the side effects. Thus, the current work had as an objective to investigate the effects of 8 weeks of supplementation with teacrine on physical performance and the training status of young amateur athletes. Methods: 22 subjects were divided into two groups – Teacrine Group (T) and Placebo Group (P) – and evaluated before and after the intervention period. Evaluations included physical tests and hormonal doses of IGF-I and IGFBP-3, utilized as markers of training status. Results: Results demonstrated that teacrine was not capable of promoting benefits in relation to physical performance of the subjects. Neither produced effects on serum secretion of IGF-I and its binding protein, IGFBP-3.Conclusion: Therefore, the findings of the present study do not support the use of teacrine for the purpose of increasing physical performance.

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.


2017 ◽  
Vol 10 (1) ◽  
pp. 214-221 ◽  
Author(s):  
Gavriil G. Arsoniadis ◽  
Petros G. Botonis ◽  
Ioannis S. Nikitakis ◽  
Dimitrios Kalokiris ◽  
Argyris G. Toubekis

Background: The magnitude of long-term changes on aerobic endurance indices provides useful information for understanding any training-induced adaptation during maturation. Objective: The aim of the present study was to compare changes in different aerobic endurance indices within two successive training years. Methods: Eight swimmers, (five male, three female; age: 14.1±1.5, height: 163.8±9.9 cm, body mass: 55.8±10 kg) were tested at four time-points, before and after the 12-week specific preparation period, within two successive training years (at year-1: start-1, end-1, at year-2: start-2, end-2). In each time-point were timed in distances of 50, 200 and 400 m front crawl to calculate the critical speed (CS). Subsequently, performed 5x200 m front crawl progressively increasing intensity and the lactate concentration was determined after each repetition. Using the individual speed vs. lactate concentration curve, the speed corresponding to 4 mmol.L-1 concentration (V4) and the speed corresponding to lactate threshold (sLT) were calculated. Results: Aerobic endurance was increased from year-1 to year-2 (effect of time, p<0.05) and no difference was observed between V4, sLT and CS at all time-points of evaluation (p>0.05). In year-1, V4, sLT and CS were unchanged even after the 12-week period (p>0.05). During year-2 of training it was only V4 that was increased from start-2 to end-2 (p<0.05), whereas sLT and CS were unchanged at the same period (p>0.05). Conclusion: The aerobic endurance indices change similarly throughout a two-year training, independent of the maturation. Possibly, V4 is more sensitive to detect training adaptations during the specific preparation period in young swimmers.


1998 ◽  
pp. 184-189 ◽  
Author(s):  
GE Krassas ◽  
TT Kaltsas ◽  
N Pontikides ◽  
H Jacobs ◽  
W Blum ◽  
...  

Leptin, a product of the ob gene, is a 16 kDa protein which is produced by adipocytes. In humans, obesity is a common finding in women with polycystic ovary syndrome (PCOS). The role, however, of leptin in PCOS is not clear. Some studies have reported increased levels of leptin in PCOS, while others report that they are normal. Also, insulin resistance is a common finding in PCOS. The aim of this study was to investigate further the role of insulin in leptin secretion in patients with PCOS by treating them for 10 days with diazoxide, an insulin-reducing compound. Eight women with PCOS, mean age 22.1 +/- 2.7 years, with mean body mass index (BMI) 28.4 +/- 5.7kg/m2, were studied. An oral glucose tolerance test (OGTT) was performed in all women and blood samples were taken before and at 30, 60, 90, 120 and 150 min after the administration of glucose. Glucose, insulin, leptin, free testosterone, delta4 androstenedione, sex hormone binding globulin (SHBG), LH, FSH, IGF-I and insulin-like growth factor-binding protein-3 (IGFBP-3) were measured in the sera taken before the administration of glucose, while glucose and insulin levels were measured in all samples which were collected after the administration of glucose. Diazoxide 300 mg daily was given to all women starting after the end of the OGTT for 10 days. A second OGTT was performed the day after the discontinuation of the diazoxide treatment. The same hormonal and biochemical parameters were also measured in all patients during the second OGTT. After the administration of diazoxide a reduction in sum insulin (262 +/- 147 vs 679 +/- 341 microU/ml. P<().01), leptin (18.5 +/- 10.6 vs 24.2 +/- 10.2 ng/ml, P<0.01), free testosterone (3.0 +/- 1.9 vs 5.1 +/- 1.9 pg/ml, P<0.01), delta4 androstenedione (3.8 +/- 1.9 vs 5.7 +/- 2.0 ng/ml, P<0.01) and IGF-I (219.5 +/- 69.2 vs 314.5 +/- 82.3 ng/ml, P<0.01) levels was observed. Serum SHBG (38.8 +/- 16.8 vs 27.8 +/- 12.1 nmol/l, P<0.01) and sum glucose levels (994.1 +/- 252.7 vs 711.1 +/- 166.1 mg/dl, P<0.05) were increased while IGFBP-3 (3.96 +/- 2.49 vs 3.75 +/- 2.24mg/l), FSH (6.2 +/- 1.8 vs 6.0 +/- 2.5 mU/l) and LH (18.9 +/- 6.7 vs 21.4 +/- 6.7 mU/l) concentrations did not change significantly. A significant positive correlation was found between serum leptin and BMI values before and after administration of diazoxide as well as between leptin, insulin and IGFBP-3 values. Also, sum insulin values correlated significantly with BMI. However, when multiple regression analysis was used this correlation was eliminated except that between leptin and BMI. This was most probably due to the small number of cases. The mechanism of the reduction of leptin levels is unclear. However, it is suggested that the concomitant decrease of insulin levels may play a role.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1782-1782 ◽  
Author(s):  
Augusto B. Federici ◽  
Francesca Gianniello ◽  
Maria T. Canciani ◽  
Pier M. Mannucci

Abstract Background and Objectives. Patients with severe forms of von Willebrand’s disease (VWD) may have frequent episodes of mucocutaneous bleeding and also of hemarthrosis or hematomas. However, little retrospective or prospective data on secondary long term prophylaxis in VWD are available. Aim of this study was to evaluate the efficacy and safety of fixed regimens of prophylaxis with factor VIII/VWF concentrates in our cohort of VWD patients with recurrent joint and gastrointestinal (GI) bleeds. Design and Methods. This is a cohort study on 452 VWD patients regularly followed up at our Center for at least three years. 89/452 cases (20%) were treated with FVIII/VWF concentrates during the last two years because of one or more bleedings and 11/89 (12%) were included in a long term prophylaxis program because of frequent recurrence of bleeds at the same sites. All patients were characterized by a bleeding severity score derived from a detailed history of 11 symptoms. Since concentrates available in Italy are still labelled in FVIII IU, patients were given 40 FVIII IU/Kg of high- (Alphanate, Fanhdi) or intermediate-purity (Haemate-P) concentrates, two times a week (joint bleeds) or every other day (GI bleeds) to maintain FVIII/VWF levels higher than baseline during prophylaxis. Effectiveness of prophylaxis was based on resolution/reduction of bleeding as well as on numbers of transfused packed red blood cells (PRBC) and days of hospitalization. Safety was measured by monitoring side effects and FVIII levels before and after every injection during the first three weeks of prophylaxis. Results. All the 11 patients were severe, as shown by high bleeding scores (&gt; 20) and VWF:RCo baseline levels &lt;10 U/dL. Prophylaxis was started because of GI bleeds in 7 patients with VWD type 3 (n=1), 2A (n=4), 2M (n=1) and 1 (n=1) and for joint bleeds only in VWD type 3 (n= 4). Prophylaxis could stop bleeding in 8 patients and largely reduced hospitalization for PRBC transfusions in the remaining 3. When prophylaxis was compared with previous on demand regimen in all 11 cases, the annual total FVIII IU (x 1000) of concentrate (a) as well as number of PRBC used (b) and days of hospitalization (c) were significantly reduced (mean ± SD, with * p &lt; 0.01): a * = 239±207 versus 385±247; b* = 9±11 versus 3±4; c* = 18±13 versus 4±3. As far as safety, FVIII levels were always &lt;180 U/dL in all VWD and no side effects, including thrombosis, were observed. Interpretations and Conclusions. Secondary long-term prophylaxis by high-and intermediate purity FVIII/VWF concentrates is effective and safe in severe forms of VWD. Cost-effectiveness of these prophylaxis regimens versus on demand therapy should be further investigated in large prospective studies.


2020 ◽  
Vol 3 (2) ◽  
pp. 110-114
Author(s):  
Dian Nurafifah ◽  
Ihda Mauliyah ◽  
Atiul Impartina

Dysmenorrhea is one of discomfort experienced by adolescent during menstruation. A Survey of 10 young women at University of Muhammadiyah Lamongan found 90% had dysmenorrhea. To reduce pain, they take pain relievers. However, the use of drugs can cause side effects, especially if long-term use can lead to addiction or dependence. Research design using Quasy Eksperiment (pretest-posttest). The study was conducted on adolescents who are experiencing dysmenorrhea. They were divided into two groups namely control and treament groups. The study began by assessing pain levels in both groups. The treatment group was given warm compresses but the control group was not given any treatment, after that reassess the level of pain. The study analyzes changes in pain levels and compares pain change in the two groups. The results showed that in the control group most of the adolescents did not experience pain changes during dysmenorrhea (86.7%), whereas in the treatment group most of the adolescents experienced a decrease in pain (93.3%). Data analysis using the Mann Whitney test showed p=0.000 where p0.05 so it can be concluded that there are differences in dysmenorrhea before and after treatment between the warm compress group and the control group. The results of this study are expected to be used as consideration in developing plans to reduce discomfort in the form of menstrual pain in a non-pharmacological manner.


Author(s):  
Yunkyeong Nam

A case study was conducted in order to track the human brain adapts to changing demands by physical exercise. Reaction time and amplitude discrimination capacity of the individual were measured with the Brain Gauge to monitor brain activity before and after aerobic exercise. The objective of the study was to determine if there were short-term and/or long-term effects of aerobic exercise.  The data suggests that there are short-term effects and some improvements in performance on the tasks when comparing metrics obtained after exercise to before exercise.  For this individual, aerobic exercise was a regular part of daily routine, there was no long-term effect detected over the relatively short duration of the study.


2021 ◽  
Author(s):  
Peter Wolf ◽  
Sylvie Salenave ◽  
Emmanuel Durand ◽  
Jacques Young ◽  
Peter Kamenicky ◽  
...  

  Background: Acromegaly is associated with changes in body composition. Long-term changes following acromegaly treatment and the impact of different treatments have been less investigated. Methods: We performed a retrospective study in 201 patients with acromegaly. Body composition was assessed by dual-energy X-ray absorptiometry (DXA). To investigate specific effects of treatment vs ageing, changes in body composition were compared in a group of patients evaluated both at the time of active and controlled disease (A>C; n=31) and in another group of patients evaluated two times while the disease was controlled (C>C; n=32). Results: In the whole cohort, IGF-I correlated with fat (r=-0.369;p<0.001) and lean mass (r=0.383;p<0.001). Patients from A>C and C>C groups were comparable for age, sex, BMI and follow-up duration (p=n.s.). Reduction in IGF-I levels was associated with an increase in fat mass and a decrease in lean mass in the A>C group, which was four and eight times more pronounced compared to the C>C group (fat mass: +39±34 vs +10±15%, p<0.001; lean mass: -8±8 vs -0.2±6%, p<0.001, respectively). Changes in fat mass were negatively associated with IGF-I (r=-0.450; p=0.011) and independent of the individual therapy. The daily dose of pegvisomant correlated with fat mass (r=0.421;p=0.002) and insulin sensitivity index (r=-0.466;p<0.001). Conclusions: Treatment of acromegaly strongly impacts body composition until biochemical disease remission, characterized by an increase in fat mass and a decrease in lean mass. These changes are closely associated with the normalization of IGF-I. Thereafter, body composition changes are similar to what is observed with ageing.


2007 ◽  
Vol 293 (3) ◽  
pp. E769-E775 ◽  
Author(s):  
Ranganath Muniyappa ◽  
John D. Sorkin ◽  
Johannes D. Veldhuis ◽  
S. Mitchell Harman ◽  
Thomas Münzer ◽  
...  

Circulating testosterone (T) and GH/IGF-I are diminished in healthy aging men. Short-term administration of high doses of T augments GH secretion in older men. However, effects of long-term, low-dose T supplementation on GH secretion are unknown. Our objective was to evaluate effects of long-term, low-dose T administration on nocturnal GH secretory dynamics and AM concentrations of IGF-I and IGFBP-3 in healthy older men (65–88 yr, n = 34) with low-normal T and IGF-I. In a double-masked, placebo-controlled, randomized study we assessed effects of low-dose T supplementation (100 mg im every 2 wk) for 26 wk on nocturnal GH secretory dynamics [8 PM to 8 AM, Q20 min sampling, analyzed by multiparameter deconvolution and approximate entropy (ApEn) algorithms]. The results were that T administration increased serum total T by 33% ( P = 0.004) and E2 by 31% ( P = 0.009) and decreased SHBG by 17% ( P = 0.002) vs. placebo. T supplementation increased nocturnal integrated GH concentrations by 60% ( P = 0.02) and pulsatile GH secretion by 79% ( P = 0.05), primarily due to a twofold increase in GH secretory burst mass ( P = 0.02) and a 1.9-fold increase in basal GH secretion rate ( P = 0.05) vs. placebo. There were no significant changes in GH burst frequency or orderliness of GH release (ApEn). IGF-I levels increased by 22% ( P = 0.02), with no significant change in IGFBP-3 levels after T vs. placebo. We conclude that low-dose T supplementation for 26 wk increases spontaneous nocturnal GH secretion and morning serum IGF-I concentrations in healthy older men.


1998 ◽  
Vol 83 (2) ◽  
pp. 542-549 ◽  
Author(s):  
Jun Nakae ◽  
Mikiko Kato ◽  
Mari Murashita ◽  
Nozomi Shinohara ◽  
Toshihiro Tajima ◽  
...  

Leprechaunism is the most severe form of insulin resistance, manifesting with abnormal glucose metabolism and retarded growth. In the present study, we investigated the biological actions of recombinant human insulin-like growth factor I (rhIGF-I) in fibroblasts derived from a patient with leprechaunism. In the same patient, we also investigated the pharmacokinetics of IGF-I and the long-term effect of rhIGF-I treatment on metabolic control and physical growth. The patient’s fibroblasts showed normal binding of IGF-I, normal phosphorylation of the β-subunit of the IGF-I receptor, and normal[ 3H]thymidine incorporation in response to IGF-I. The fibroblast studies suggested that the patient would respond to IGF-I therapy, but certainly did not exclude the possibility of IGF-I resistance in vivo. Administration of recombinant human GH at the dose of 2.0 IU/kg for 3 consecutive days induced a minimal response of serum total IGF-I and IGF-binding protein-3 (IGFBP-3), suggesting partial GH resistance. To increase the serum total IGF-I level, we administered rhIGF-I with combination therapy of intermittent and continuous sc injection. This sustained the serum total IGF-I level, but not the serum IGFBP-3 level, within the normal range. The patient was treated with combination therapy of rhIGF-I by both sc injection and continuous sc infusion for 6 yr and 10 months. Administration of rhIGF-I at total daily dose of 1.6 mg/kg maintained her growth rate and hemoglobin A1c level nearly within the normal range. These findings suggest 1) that this leprechaun patient has an IGF-Ideficient state and partial GH resistance, as reflected by impaired production of IGF-I and IGFBP-3; 2) that rhIGF-I treatment works effectively for preventing postnatal growth retardation and normalizing glucose metabolism in patients with extreme insulin resistance; 3) that this treatment requires relatively higher dose of rhIGF-I; and 4) that treatment appears to be safe and devoid of adverse effects.


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