Curcumin, a polyphenol, has been suggested to improve metabolic byproduct clearance and increase nitric oxide production in working muscle. These purported effects may delay neuromuscular fatigue. Therefore, the purpose of this study was to examine the effects of curcumin in combination with fenugreek (CUR) or fenugreek soluble fiber alone (FEN) on the neuromuscular fatigue threshold (PWCFT), time to exhaustion (Tlim) on a graded exercise test (GXT), and O2peak in untrained subjects.Forty-seven,college-aged, aerobically untrained individuals were randomly assigned to one of three supplementation groups; placebo (PLA, n=15),curcumin + fenugreek, CurQfen® (CUR, n=18), or fenugreek soluble fiber (FEN, n=14). All subjects performed a maximal GXT on a cycle ergometer to determine the PWCFT, Tlim, and O2peak before (PRE-test) and after (POST-test) 28 days of daily supplementation. Statistical analyses included 3 separate, one-way ANCOVAs to determine if there were any differences among the groups (PLA, CUR, FEN) for adjusted post-test scores for the PWCFT, O2peak, and Tlim. The respective pre-test score was used as the covariate. In addition, reliability analyses (PRE- to POST-test) for the PLA group were used to calculate the minimal difference needed to be real (MD). The adjusted POST PWCFTvalues showed no statistical differences between groups (F= 3.141p= 0.053); however pairwise LSD comparisons indicated a significant difference between the CUR and PLA groups (p= 0.016), but not between the CUR and FEN groups. Therefore, separate one-way ANCOVAs were used to examine the adjusted PWCFTmeans for the PLA vs. CUR (F = 4.906, p =0.035) and the PLA vs. FEN (F = 2.969, p = 0.097). The one- way ANCOVA for O2peak (F= 0.612 p= 0.547) and Tlim(F = 0.688, p = 0.508) values showed no statistical difference among the groups. Individual responses in each group showed ~ 20% of subjects in the CUR group, ~ 7% in the FEN group, and ~6% in the PLA group had values greater than the MD for the PWCFT, but none of the subjects in the PLA, FEN, or CUR groups exceeded the MD for O2peak or Tlim. These findings indicatedCurQfen® supplementation increased the PWCFTcompared to a placebo, but not compared to fenugreek soluble fiber alone. However, there were no effects of CurQfen® on O2 peak or Tlim. The mechanisms responsible for delaying time to neuromuscular fatigue may include increased NO production and increased blood flow to remove metabolic byproducts; however, the cellular changes which could lead to increases in Tlim andO2peak may not have been sensitive to the GXT protocol or the given dosage of curcumin supplementation. Considering individual responses, CurQfen® supplementation resulted in a real change in the PWCFTfor a small portion of the subjects (~20%). These findings suggested that CurQfen® supplementation without exercise training may help to improve time to neuromuscular fatigue in certain individuals, but the group mean analyses were not necessarily reflective of the responses for a majority of the subjects.

Tyrimo pagrindimas ir hipotezė. Didinti jėgai treniruotėse naudojami skirtingi svoriai, pasipriešinimas, darbo apimtis, poilsio periodai, dažnis, ir atlikimo greitis. Tradicinę treniruočių priemonę su dideliu pasipriešinimu, galime pakeisti mažu pasipriešinimu kartu apribojant raumenų kraujotaką. Hipotezė: vienkartinė 15; 10; 5 ar 3 minučių trukmės 200 mm Hg slėgio okliuzija gali turėti įtakos fiziniam darbingumui ir kraujotakos intensyvumui. Tyrimo tikslas. Išanalizuoti blauzdos raumenų arterinės kraujotakos intensyvumo kaitą ir fizinį darbingumą be ir su skirtingos trukmės 200 mm Hg slėgio okliuzijomis. Uždaviniai. 1. Nustatyti blauzdos raumenų arterinės kraujotakos intensyvumą ramybėje be ir su 200 mm Hg okliuzija. 2. Nustatyti arterinio kraujo spaudimo (AKS) kaitą ramybėje be ir su 200 mm Hg okliuzija. 3. Nustatyti blauzdos raumenų darbingumo kaitą be ir su 15min, 10 min, 5 min ir 3 min trukmės, 200 mm Hg slėgio, okliuzijomis. 4. Nustatyti blauzdos raumenų arterinės kraujotakos intensyvumą ir AKS kaitą po fizinio krūvio, be ir su 15 min, 10 min, 5 min ir 3 min trukmės, 200 mm Hg slėgio, okliuzijomis Tyrimo metodai. Dinamometrija, ergometrija, veninė okliuzinė pletizmografija, Tyrimų organizavimas. Pirmoje tyrimų dalyje kontrolinėje grupėje dalyvavo 6, o eksperimentinėje grupėje 12 vyrų sportuojančių ištvermės sporto šakose. Grupėse 20 minučių registruojama arterinė kraujotaka ramybėje, o eksperimentinėje grupėje atlikta 15 minučių 200 mm Hg slėgio okliuzija. Antroje... [toliau žr. visą tekstą] / Research background and hypothesis. Different weights, resistance, scope of work, rest periods, frequency, and performance velocity are used to increase strength in training sessions. The traditional training facility with high resistance can be replaced by low resistance while limiting muscle blood flow. Hypothesis: a single 15, 10, 5 or 3 minute 200 mm Hg occlusion pressure can affect physical working capacity and blood flow intensity. Research aim. Analyse changes in the intensity of the calf muscle arterial blood flow and physical working capacity with and without 200 mm Hg pressure occlusion of different duration. Research tasks. 1. Establish arterial blood flow of the calf muscle at rest with and without 200 mm Hg occlusion. 2. Establish changes in arterial blood pressure at rest with and without 200 mm Hg occlusion. 3. Establish changes in the calf muscle work with and without 15 min, 10 min, 5 min and 3 min 200 mm Hg pressure occlusion. 4. Establish changes in the calf muscle blood flow and arterial blood pressure after exercise, with and without 15 min, 10 min, 5 min and 3 min 200 mm Hg pressure occlusion. Research methods. Dynamometry, ergometry, venous occlusive plethysmography. Research organization. In first part of the research, the control group included six and the experimental group - 12 male athletes in endurance sports. In both groups we recorded arterial blood flow at rest for 20 min; in the experimental group we applied 15 min 200 mm Hg occlusion. In the... [to full text]

This study investigated the effects of high intensity interval training (HIIT) and β-hydroxy-β-methylbutyric free acid (HMBFA) on the onset of neuromuscular fatigue in healthy young men and women. Thirty-seven subjects (22 men and 15 women; mean ± SD age = 22.8 ± 3.4yrs) completed an incremental cycle ergometer test (GXT) to exhaustion. During the GXT, electromyography (EMG) signals from the right vastus lateralis were recorded to determine the power output at the onset of neuromuscular fatigue (PWCFT), and peak wattage was used to assign individual training loads. After baseline testing (PRE), subjects were randomly assigned to one of three groups: control (C, n = 9), training with placebo (P, n = 14), or training with supplementation (S, n = 14). Subjects assigned to P and S completed 12 HIIT sessions over 4 weeks while subjects assigned to C were asked to maintain their normal diet and activity patterns. After 4 weeks, subjects returned for post-testing (POST). The PWCFT values (W) were determined using a DMAX method. The EMG amplitude root mean square (µVrms) values were used to generate a third-order polynomial regression (3PR) representing the increase in µVrms versus time of the GXT. The onset of fatigue (TF) was defined as the x-value (time, s) of the point on the 3PR that measured the maximal perpendicular distance from the line between the first and last data points. TF was used to estimate PWCFT according to the equation: PWCFT = PO + a · (n/N), where PO is the power output of the stage in which TF occurred, a is the increment in power output between GXT stages (25W), n is the difference (s) between TF and the beginning of the stage during which TF occurred, and N is the duration of a stage (120s). A two-way repeated measures ANOVA was used to identify group × time interaction for PWCFT. If a significant interaction occurred, one-way factorial ANOVAs were used. Fisher's least significant difference post hoc comparisons were performed between groups. If a significant main effect occurred, dependent samples t-tests with Bonferroni corrections (p = [0.05/3] = 0.017) were performed across time for each group. The two-way ANOVA resulted in a significant interaction (F = 6.69, p = 0.004). Follow-up analysis with one-way ANOVA resulted in no difference among groups at PRE (F = 0.87, p = 0.43), however a significant difference was shown for POST values (F = 5.46, p = 0.009). Post-hoc analysis among POST values showed significant differences between S and both P (p = 0.034) and C (p = 0.003). No differences (p = 0.226) were noted between P and C. Paired samples t-tests detected significant changes following HIIT for S (p < 0.001) and P (p = 0.016), but no change in C (p = 0.473). Results of this study indicate that HIIT was effective in delaying the onset of fatigue, but supplementation with HMBFA in conjunction with HIIT was more effective than HIIT alone. An increase in PWCFT represents an increase in the maximal power output an individual can sustain without eliciting fatigue. Therefore, HIIT can be used to improve performance in both endurance activities as well as intermittent sports. In addition, HMBFA supplementation is a simple method that can be used to maximize the benefits of HIIT. Acknowledgments: Metabolic Technologies, Inc. provided the supplement and funding for this study.