Omega-3 Supplementation, Menstrual Cycle, and Acute Eccentric Exercise on Plasma Lipid Profiles

Omega-3 fatty acids supplementation and the menstrual cycle may independently influence plasma lipids and lipoproteins following acute exercise. PURPOSE: The current study investigated the effects of dietary fish oil supplement and acute eccentric exercise on plasma lipids and lipoproteins during two different phases of the menstrual cycle [mid-follicular (MF) vs. mid-luteal phase (ML)]. METHODS: As a double-blind, placebo-controlled design, 22 healthy young females (age= 20.86±1.39 years) volunteered. Participants were randomly assigned to either the fish oil (N=11) or the placebo (N=11) group. The fish oil group took a total of 6 capsules of fish oil per day (6g total; each capsule with 2.4 g of eicosapentaenoic acid and 1.8 g of docosahexaenoic acid), while the placebo group took 6 capsules of safflower oil/day (6g total; 2.8 g of lauric acid, 1.1g of myristic acid, 0.4 g of caprylic acid, 0.4 g of oleic acid, and 0.09 mg of linoleic acid) for 3 weeks. Participants in each group performed an acute eccentric single-leg exercise protocol during the MF and ML phases, which consisted of 10 sets of 10 repetitions with a 3-min resting between sets at an isokinetic speed of 30⁰/sec. The leg exercised for the MF phase was randomly selected and the opposing leg exercised during the ML phase. Plasma samples were collected at pre-, 6-hours post-exercise (6-hr PE), and 24-hours post-exercise (24-hr PE)] to analyze total cholesterol (TC), high-density lipoprotein (HDL-C), lipoprotein (a), very low-density lipoprotein (VLDL-C), and low-density lipoprotein (LDL-C). Data were analyzed using a multivariate analysis of variance (p \u3c 0.05). If a significant interaction was found, a Tukey’s post-hoc test was performed. RESULTS: Plasma lipids and lipoproteins were not different between the fish oil and placebo groups or before and after the acute eccentric leg exercise. However, HDL-C was significantly higher (p = 0.041) during the ML (61.66 ± 2.44 mg/dL) phase than that of the MF (54.53 ± 2.44 mg/dL) phase. CONCLUSION: Although it didn’t reach a statistical significance, the overall lipid and lipoprotein profile tended to improve following a relatively short-term fish oil supplement in healthy, young women. Acute eccentric exercise may not negatively affect plasma lipids and lipoproteins. Elevated HDL-C during the mid-luteal phase may possibly be associated with increased estradiol levels. It is recommended for future studies that an extended period of fish oil supplement using different dosages and exercise regimen be implemented to examine a long-term benefit of fish oil supplement in a variety of sample groups

Fiber Type Profile and its Relation to Wilks Coefficient in Both Male and Female Powerlifters

While powerlifters tend to display higher fast-twitch fiber content, it is unknown if this content predicts competitive performance via Wilks coefficient. Purpose: to 1) compare the myosin heavy chain (MHC) fiber type (FT) profiles between powerlifters and sedentary controls of both sexes, and 2) determine if fast-twitch fiber content predicts Wilks coefficient. Methods: Twelve actively competing powerlifters (PL; n=6M/6F; age=21±1.0y; 3.0±1.8y competing; 7.3±6.6 meets attended) and ten sedentary controls (CON; n=5M/5F; age=19.4±2.0y) underwent vastus lateralis muscle biopsies, with samples analyzed for MHC isoform content via mixed homogenate SDS-PAGE. Individual MHC isoform differences between group and sex were analyzed using a 3x2x2 (FT [MHC I, IIa, & IIx] x group [PL & CON] x sex [male & female]) ANOVA and MHC IIa content was compared to Wilks coefficient using Pearson correlation coefficient at pResults: Male PL MHC isoform distribution was 50±6% I, 45±6% IIa, and 5±11% IIx, vs 46±6% I, 53±6 IIa, and 0% IIx in PL females. Conversely, male CON MHC distribution was 33±5% I, 38±7% IIa, and 30±8% IIx, vs 35±9% I, 44±8% IIa, and 21±17% IIx in CON females. Analysis revealed a significant FT main effect (pConclusions:These results illustrate powerlifters have higher MHC I and IIa proportions, as well as lower MHC IIx content compared to sedentary controls. While overall limited by sample size, MHC IIa content does not appear to be a significant predictor of powerlifting Wilks coefficient, suggesting this characteristic alone does not define powerlifter skill variations

Ubiquitin Proteasome System Activity is Suppressed by Curcumin Following Exercise-Induced Muscle Damage in Human Skeletal Muscle

PURPOSE: Curcumin is a natural polyphenolic compound with antioxidant and anti-inflammatory properties. In vitro and in vivo animal studies have demonstrated that exposure to curcumin leads to dysregulation of the ubiquitin-proteasome system (UPS). However, to date, no study has investigated curcumin’s ability to influence UPS activity in a human model. Therefore, the purpose of this study was to investigate the effects of curcumin supplementation on markers of UPS activity in the presence of elevations in UPS activity due to exercise-induced muscle damage. METHODS: Twenty-three recreationally active male and female participants between the ages of 18-30 were randomized into a curcumin (CUR; n=11) or placebo (PLA; n=12) group. Both groups were instructed to consume 2 g of their respective supplement and 20 mg of piperine for 11 consecutive days. Following 8 consecutive days of supplementation, participants performed a 45 minute eccentrically-biased muscle damaging treadmill protocol at 60% VO2max. Muscle biopsies and delayed onset muscle soreness (DOMS) analyses were performed 30 minutes prior and 3, 24, 48, and 72 hours following exercise-induced muscle damage. Skeletal muscle ubiquitin, MAFbx/Atrogin-1, ubiquitin specific peptidase 19 (USP19), and chymotrypsin-like protease concentrations were measured using ELISA. A 3-way repeated measures ANOVA with pairwise comparisons was conducted with significance set at p≤0.05. RESULTS: Both groups had a significant time effect for DOMS (p \u3c .001). Pairwise comparisons indicated DOMS was significantly greater from baseline at all time points except 72 hours following muscle damage. No significant differences were found for USP19 between groups. Regardless of time, a significant main effect for condition was observed for ubiquitin (p=.016) and MAFbx/Atrogin-1 (p=.006) where CUR was significantly lower than PLA. Additionally, a significant main effect for gender was observed for MAFbx/Atrogin-1 (p=.013) where females were greater than males. A significant group x gender interaction was found for chymotrypsin-like protease (p = .049) where males had lower values with curcumin supplementation while females had slightly higher. CONCLUSION: Curcumin supplementation in humans does appear to dysregulate UPS activity in the presence of exercise-induced muscle damage. Specifically, curcumin’s ability to suppress protein ubiquination provides preliminary evidence of curcumin supplementation’s potential therapeutic role in decreasing protein degradation associated with skeletal muscle damage and perhaps other atrophic scenarios

Restrictive Breathing Mask Reduces Total Repetitions in Resistance-Trained Males: An Ongoing Study

Recently a popular exercise training device has been developed, which has been promoted by companies as a training aid, known as a restrictive breathing mask (RBM).The RBM is designed to simulate training at higher altitudes and has become commonplace for individuals to utilize during resistance-training sessions. PURPOSE: The purpose of this study was to examine the impact of a RBM on muscle performance and perceptual measures in resistance-trained males. METHODS: A cross-over study design was utilized in 9 resistance-trained males with performance trials separated by 7 days. A baseline strength testing session was completed for 12RM for squat, leg press, and leg extension. Participants completed the lower body workout with no mask or RBM. After the initial warm up, participants completed 4 sets of reps to failure of squats, leg press, and leg extension with 2 minutes rest between sets and 3 minutes between exercises. Heart rate was collected immediately post set. Participants completed a 10cm visual stress scale immediately post resistance training session and Session RPE (SRPE) was collected 10 minutes post. Paired T-tests were utilized to analyze total session reps, SRPE, average post set session heart rate, and session stress scale. RESULTS: There was a significant reduction in total session reps during the RBM trial compared to the no mask trial (p\u3c 0.001). SRPE was significantly higher during the RBM trial compared to the no mask trial (p= 0.003). There was a significant elevation in perceived stress during the RBM trial (p= 0.01). Finally, there was a statistically significant increase in post set heart rate during the RBM session (p=0.04) CONCLUSION: Based on the performance variables, it appears that a RBM reduces the total repetitions that an individual can complete during an acute bout of resistance training, while also increasing the perceived difficulty and stressfulness of the bout. Subsequently, a reduction in mechanical stimuli could result in a diminished hypertrophic response over time

The Effects of Short-Term Detraining and Subsequent Retraining on Body Composition and Muscle Performance in Males Consuming a Whey Protein or Carbohydrate Supplement

An acute bout of resistance exercise (RE) can up-regulate processes that stimulate muscle protein synthesis (MPS). Additionally, nutritional strategies involving carbohydrate (CHO) and whey protein (WP) supplementation can augment MPS. However, resistance training (RT) induced muscle anabolism during the early phases of training can attenuate over time. The use of a short-term cessation of training (detraining; DT) can potentially restore the attenuated muscular anabolic adaptive responses. Therefore, the purpose of this study was to explore the effects of a successive cycle of detraining and retraining (ReT) in humans on body composition and muscle performance. Resistance-trained males (age 20.95 ± 1.23 y; n=20) were recruited and randomized into one of two groups (WP or CHO; 25 grams) in a double-blind fashion. Both groups followed a standardized 4 days per week resistance-training program for 4 weeks, carried out 2 weeks of DT and continued the resistance-training program for another 4 weeks of ReT. Participants were instructed to consume their respective supplement only on workout days during RT, but every day during DT. Research visits were conducted at baseline, 4 weeks (post-RT), 6 weeks (post-2-week-DT), and after 10 weeks (post-ReT). Each visit consisted of body composition assessments and muscular strength and endurance testing using the bench press and angled leg press exercises. Four-day diet records, workout logs, and supplement compliance forms were utilized. Factorial 2x4 (group by time) ANOVAs with repeated measures were conducted using SPSS (version 20.0) with a probability level of ≤ .05. There were no significant group by time interactions for lean or fat mass changes throughout the study (p \u3e .05). However, both groups were able to retain lean mass following 2 weeks of DT. The WP group appeared to have an elevation in lean mass (+1.58kg on average) by the end of ReT in comparison to baseline, even though it was not statistically significant (p \u3e .05). Leg press strength (LPS) increased throughout the study (p=.003), and neither group showed a decrease in LPS following DT. There were no group-by-time interactions or group differences between WP and CHO for bench press strength (BPS), bench press endurance (BPE), leg press endurance (LPE), or any dietary variables (p \u3e .05). Interestingly, the WP group presented a non-significant overall increase in lean mass compared to the CHO group by the end of 10 weeks. LPS and BPS were also elevated and retained respectfully following DT. In summary, a short-term 2 week cycle of DT in resistance trained males maintained both muscle mass and muscular strength, which potentially reinforces the importance of recovery

Effect of Pre-Exercise Nutrition on Human Skeletal Muscle UCP3 Expression

BACKGROUND: Increased UCP3 expression in skeletal muscle after exercise may be attributed to elevated free fatty acids (FFA) that are known to directly activate UCP3 expression. Pre-exercise glucose consumption has shown to blunt UCP3 expression in response to exercise. Since glucose ingestion before and during exercise is typically not a common practice, the goal of the present study was to assess the effect of a multi-macronutrient meal (drinkable shake) in the pre-exercise period towards human skeletal muscle UCP3 expression. METHODS: Using a crossover design, untrained participants performed an endurance exercise session (350 kcal at 70% of their VO2max) after two experimental conditions 1) consumption of a multi-macronutrient meal and 2) a fasting period of 8 h. Blood samples were taken at baseline, pre-exercise, post-exercise, 1h, and 4h post-exercise, while muscle biopsies were taken at the last four time points. RESULTS: A significant increase in FFA was observed in the fasting condition (p= 0.046) as well as a significant increase in UCP3 mRNA and protein expression at post-exercise (p= 0.042) and 4 h post-exercise (p= 0.036) respectively, in the multi-macronutrient meal condition. DISCUSSION: Variables showed a total opposite response to what has been reported after the consumption of pure glucose before an exercise session. Instead of observing a decrease in UCP3 expression in the non-fasting condition, we observed a significant increase in UCP3 mRNA and protein concentration in the multi-macronutrient condition. According to previous research, variables such as the protein and fat content from the multi-macronutrient meal, as well as the insulin levels, could have played key roles in altering UCP3 mRNA and protein expression in the multi-macronutrient condition; however, further research is needed to confirm this hypothesis. CONCLUSION: The expression of UCP3 mRNA and protein expression as a result of exercise might be controlled by factors other than FFA