Long-Chain Omega-3 Fatty Acid Supplementation and Exercise-Induced Muscle Damage: EPA or DHA?

PURPOSE: Long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) may enhance recovery from exercise-induced muscle damage (EIMD). However, it is unclear if the effects are due to EPA, DHA, or both. The purpose of this investigation was to examine the effect of EPA + DHA, EPA, and DHA compared with placebo (PL) on muscular recovery. METHODS: Thirty males were randomized to 4 g·d -1 EPA + DHA ( n = 8), EPA ( n = 8), DHA ( n = 7), or PL ( n = 7). After 7-wk supplementation, a downhill running (20 min, 70% V̇O 2max , -16% gradient) plus jumping lunges (5 × 20 reps, 2-min rest intervals) muscle damage protocol was performed. Indices of muscle damage, soreness, muscle function, and inflammation were measured at baseline and throughout recovery. The omega-3 index (O3i; %EPA + %DHA in erythrocytes) was used to track tissue EPA and DHA status. RESULTS: After supplementation, the O3i was significantly higher than PL in all experimental groups ( P < 0.001). Leg press performance was lower in the PL group at 24 h compared with EPA ( P = 0 .019) and at 72 h for EPA ( P = 0.004) and DHA ( P = 0 .046). Compared with PL, muscle soreness was lower in the DHA ( P = 0.015) and EPA ( P = 0.027) groups at 48 h. Albeit nonsignificant, EPA + DHA tended to attenuate muscle soreness ( d = 1.37) and leg strength decrements ( d = 0.75) compared with PL. Jump performance and power metrics improved more rapidly in the EPA and DHA groups (time effects: P < 0.001). Measures of inflammation, range of motion, and muscle swelling were similar between groups ( P > 0.05). CONCLUSIONS: Compared with PL, 4 g·d -1 of EPA or DHA for 52 d improves certain aspects of recovery from EIMD. EPA + DHA did not clearly enhance recovery. Equivalent dosing of EPA + DHA may blunt the performance effects observed in EPA or DHA alone.

Omega-3 Index improves after increased intake of foods with omega-3 polyunsaturated fatty acids among US service academy cadets.

The inclusion of omega-3 fatty acids in our dietary intake is important for performance and recovery and may reduce the risk of various health issues. Studies have shown the omega-3 fatty acid status of US service members is low. The purpose of this study was to evaluate whether offering fish and omega-3-enhanced foods would increase the Omega-3 Index (O3I). We hypothesize cadets will increase O3I with enhanced omega-3 options more than fish alone. Food service venues at 3 US service academies offered fish and other omega-3 foods to cadets for 12 weeks. Questionnaires were used to collect information on the dietary habits and omega-3 food intake of participants. The O3I of each participant was measured at baseline, mid- (6 weeks), and after data collection (12 weeks) time points. Following the 12 weeks, we found a significant increase in O3I. More specifically, the intake of other omega-3 foods, smoothies (3 per week) and toppings (3 per week), increased O3I in cadets. This study identified a strategy encouraging omega-3 food intake and improving O3I among cadets. These results help us understand how we can more effectively impact military service member nutrition for optimal health and performance.

Sex differences in body composition and serum metabolome responses to sustained, physical training suggest enhanced fat oxidation in women compared with men.

Sex differences in energy metabolism during acute, submaximal exercise are well documented. Whether these sex differences influence metabolic and physiological responses to sustained, physically demanding activities is not well characterized. This study aimed to identify sex differences within changes in the serum metabolome in relation to changes in body composition, physical performance, and circulating markers of endocrine and metabolic status during a 17-day military training exercise. Blood was collected, and body composition and lower body power were measured before and after the training on 72 cadets (18 women). Total daily energy expenditure (TDEE) was assessed using doubly labeled water in a subset throughout. TDEE was greater in men (4,085 ± 482 kcal/d) than in women (2,982 ± 472 kcal/d, P < 0.001), but not after adjustment for dry lean mass (DLM). Men tended to lose more DLM than women (mean change [95% CI]: -0.2[-0.3, -0.1] vs. -0.0[-0.0, 0.0] kg, P = 0.063, Cohen's d = 0.50) and have greater reductions in lower body power (-244[-314, -174] vs. -130[-209, -51] W, P = 0.085, d = 0.49). Reductions in DLM and lower body power were correlated (r = 0.325, P = 0.006). Women demonstrated greater fat oxidation than men (Δfat mass/DLM: -0.20[-0.24, -0.17] vs. -0.15[-0.17, -0.13] kg, P = 0.012, d = 0.64). Metabolites within pathways of fatty acid, endocannabinoid, lysophospholipid, phosphatidylcholine, phosphatidylethanolamine, and plasmalogen metabolism increased in women relative to men. Independent of sex, changes in metabolites related to lipid metabolism were inversely associated with changes in body mass and positively associated with changes in endocrine and metabolic status. These data suggest that during sustained military training, women preferentially mobilize fat stores compared with men, which may be beneficial for mitigating loss of lean mass and lower body power.NEW & NOTEWORTHY Women preferentially mobilize fat stores compared with men in response to sustained, physically demanding military training, as evidenced by increased lipid metabolites and enhanced fat oxidation, which may be beneficial for mitigating loss of lean mass and lower body power.

The effect of fish oil supplementation on resistance training-induced adaptations.

BACKGROUND: Resistance exercise training (RET) is a common and well-established method to induce hypertrophy and improvement in strength. Interestingly, fish oil supplementation (FOS) may augment RET-induced adaptations. However, few studies have been conducted on young, healthy adults. METHODS: A randomized, placebo-controlled design was used to determine the effect of FOS, a concentrated source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), compared to placebo (PL) on RET-induced adaptations following a 10-week RET program (3 days·week-1). Body composition was measured by dual-energy x-ray absorptiometry (LBM, fat mass [FM], percent body fat [%BF]) and strength was measured by 1-repetition maximum barbell back squat (1RMSQT) and bench press (1RMBP) at PRE (week 0) and POST (10 weeks). Supplement compliance was assessed via self-report and bottle collection every two weeks and via fatty acid dried blood spot collection at PRE and POST. An a priori α-level of 0.05 was used to determine statistical significance and Cohen's d was used to quantify effect sizes (ES). RESULTS: Twenty-one of 28 male and female participants (FOS, n = 10 [4 withdrawals]; PL, n = 11 [3 withdrawals]) completed the 10-week progressive RET program and PRE/POST measurements. After 10-weeks, blood EPA+DHA substantially increased in the FOS group (+109.7%, p< .001) and did not change in the PL group (+1.3%, p = .938). Similar between-group changes in LBM (FOS: +3.4%, PL: +2.4%, p = .457), FM (FOS: -5.2%, PL: 0.0%, p = .092), and %BF (FOS: -5.9%, PL: -2.5%, p = .136) were observed, although, the between-group ES was considered large for FM (d = 0.84). Absolute and relative (kg·kg [body mass]-1) 1RMBP was significantly higher in the FOS group compared to PL (FOS: +17.7% vs. PL: +9.7%, p = .047; FOS: +17.6% vs. PL: +7.3%, p = .011; respectively), whereas absolute 1RMSQT was similar between conditions (FOS: +28.8% vs. PL: +20.5%, p = .191). Relative 1RMSQT was higher in the FOS group (FOS: +29.3% vs. PL: +17.9%, p = .045). CONCLUSIONS: When combined with RET, FOS improves absolute and relative 1RM upper-body and relative 1RM lower-body strength to a greater extent than that observed in the PL group of young, recreationally trained adults.

International society of sports nutrition position stand: tactical athlete nutrition.

This position stand aims to provide an evidence-based summary of the energy and nutritional demands of tactical athletes to promote optimal health and performance while keeping in mind the unique challenges faced due to work schedules, job demands, and austere environments. After a critical analysis of the literature, the following nutritional guidelines represent the position of the International Society of Sports Nutrition (ISSN). General Recommendations: Nutritional considerations should include the provision and timing of adequate calories, macronutrients, and fluid to meet daily needs as well as strategic nutritional supplementation to improve physical, cognitive, and occupational performance outcomes; reduce risk of injury, obesity, and cardiometabolic disease; reduce the potential for a fatal mistake; and promote occupational readiness. Military Recommendations: Energy demands should be met by utilizing the Military Dietary Reference Intakes (MDRIs) established and codified in Army Regulation 40-25. Although research is somewhat limited, military personnel may also benefit from caffeine, creatine monohydrate, essential amino acids, protein, omega-3-fatty acids, beta-alanine, and L-tyrosine supplementation, especially during high-stress conditions. First Responder Recommendations: Specific energy needs are unknown and may vary depending on occupation-specific tasks. It is likely the general caloric intake and macronutrient guidelines for recreational athletes or the Acceptable Macronutrient Distribution Ranges for the general healthy adult population may benefit first responders. Strategies such as implementing wellness policies, setting up supportive food environments, encouraging healthier food systems, and using community resources to offer evidence-based nutrition classes are inexpensive and potentially meaningful ways to improve physical activity and diet habits. The following provides a more detailed overview of the literature and recommendations for these populations.

Differential recovery rates of fitness following U.S. Army Ranger training.

OBJECTIVES: To investigate tactically-related physical performance and body composition recovery following U.S. Army Ranger training. DESIGN: Prospective cohort. METHODS: Physical performance was comprehensively assessed using a tactically-related performance battery (i.e., Ranger Athlete Warrior assessment) in 10 male Soldiers at baseline (BL) two-weeks (P1), and six-weeks (P2) post-Ranger School. Body composition was determined using DXA. A one-way repeated measures ANOVA was used followed by Bonferroni-adjusted pairwise comparisons when group differences existed (p≤0.05). Pearson correlation coefficients were used to establish associations between changes in fitness and body composition. RESULTS: All performance domains except the bench press and deadlift worsened following training. Speed/mobility (Illinois agility test, seconds - BL: 16.20±0.86 vs. P2: 18.66±2.09), anaerobic capacity (300-yard shuttle run, seconds - BL: 62.95±6.17 vs. P2: 67.23±5.91), core strength (heel clap, repetitions - BL: 15.80±4.08 vs. P2: 11.50±4.95), and aerobic endurance (beep test, stage - BL: 9.95±2.18 vs. P2: 7.55±1.07) had not recovered by P2. Only upper body muscular endurance and strength (metronome push-up and pull-up, respectively) were similar to BL by P2. Percent body fat increased from 15.62±3.94 (BL) to 19.33±2.99 (P2) (p<0.001). There were no significant associations between changes in body composition and performance. CONCLUSIONS: A comprehensive characterization of physical performance and body composition revealed Rangers did not experience full recovery of fitness six weeks after training. Optimal recovery strategies are needed to return Soldiers to a state of readiness following arduous training.

The relationship between vitamin D status and depression in a tactical athlete population.

BACKGROUND: Stressors inherent to the military, such as combat exposure, separation from family, and strenuous training, collectively contribute to compromised psychological resilience and greatly impact military performance. METHODS: This retrospective review of records was conducted to determine whether vitamin D status was associated with diagnoses of depression and if diagnoses differed by geographic location. RESULTS: Depression (defined using diagnostic codes) was more prevalent in individuals who were diagnosed with vitamin D deficiency (20.4%) than in individuals who were not (4.2%). After adjustment, vitamin D deficient diagnoses remained significantly associated with depression diagnoses (OR = 1.22; 95% CI, 1.11-1.33, p < 0.001). Furthermore, vitamin D deficient diagnoses were strongly associated with geographic latitude (r2 = 0.92, p = 0.002). CONCLUSION: These results suggest that service members stationed at installations located at northerly latitudes may be at increased risk for vitamin D deficiency. Furthermore, vitamin D deficient service members may be at higher risk for diagnosis of depression. As a number of military service members avoid reporting symptoms or seeking treatment, vitamin D status may be a useful screening tool to identify service members at risk for depression.

Relationship of Strength and Conditioning Metrics to Success on the Army Ranger Physical Assessment Test.

Barringer, ND, McKinnon, CJ, O'Brien, NC, and Kardouni, JR. Relationship of strength and conditioning metrics to success on the army ranger physical assessment test. J Strength Cond Res 33(4): 958-964, 2019-The purpose of our study was to compare standard strength and conditioning assessments in the Ranger Athlete Warrior (RAW) assessments to a tactical assessment of the Ranger Physical Assessment Test (RPAT) to determine what influence, if any, that they may have on the RPAT outcome. We analyzed RAW and RPAT data on 1,141 soldiers attempting the Ranger Assessment and Selection Program I (RASP I) for entrance into the 75th Ranger Regiment as part of their routine program data collection from July 2014 to July 2017. We found better performance in the broad jump, pull-ups, and average 300-yard shuttle time was associated with improved odds of passing the RPAT. For every increasing 2.54 centimeters in broad jump, the odds of passing the RPAT increased by 4% (OR = 1.04, 95% CI [1.01-1.07]). Each additional pull-up was associated with 6% better odds (OR = 1.06, 95% CI [1.01-1.12]) of passing the RPAT, and every second faster in the 300-yard shuttle was associated with 9% better odds of passing the RPAT (OR = 1.09, 95% CI [1.03-1.14]). The results of this study indicate that lower-body power, pulling strength, and anaerobic conditioning seemed to have the greatest influence on RPAT success. Our current results provide guidance to Strength Coaches or TSAC-Fs preparing tactical athletes for this specific or similar tactical assessment as better performance was found for tactical athletes with greater lower-body power, pulling strength, and anaerobic endurance.

Impact of a purported nootropic supplementation on measures of mood, stress, and marksmanship performance in U.S. active duty soldiers.

BACKGROUND: The purpose of this study was to determine the impact of a commercially available purported nootropic supplement on mood, stress, and rifle marksmanship accuracy and engagement time via an Engagement Skills Trainer. METHODS: In this double-blind, placebo-controlled trial, 43 U.S. active duty Soldiers participating in a professional military course were assigned to treatment (n = 20; 16 males and 4 females) or placebo (n = 23; 15 males and 8 females) based on initial marksmanship score. The study period was 31 days (testing performed on days 1 and 31, supplementation days 2 through 30). Participants were instructed to consume 2 pills at breakfast and 1 pill at dinner for a total of 3 pills per day (1925 mg) of either the Alpha Brain® nootropic supplement or a placebo. Height, weight, cortisol (in a hair sample), body composition using multi-frequency tetrapolar bioelectrical impedance (InBody 720), and marksmanship (Engagement Skills Trainer 2000). Marksmanship was assessed in the prone position with zeroed M-4 rifles with a twenty target protocol with targets presenting and remaining for 3 s at set intervals. Participants' performance were assessed with hits versus misses, distance of hit from target center mass (DCM), and target engagement speed. Statistical analysis via SPSS Statistics 21 (IBM) was conducted using a repeated measures ANOVA with significance set at P < 0.5. RESULTS: There was no statistically significant difference between Treatment and Placebo for hits (TreatmentPre 18.5 ± 1.5, TreatmentPost 19.4 ± 0.8, PlaceboPre18.2 ± 2.9, PlaceboPost19.4 ± 1.3), initial reaction time in seconds (TreatmentPre 1.65 ± 0.28, TreatmentPost 1.43 ± 0.28, PlaceboPre1.59 ± 0.29, PlaceboPost1.41 ± 0.21), mean reaction time in seconds (TreatmentPre 1.60 ± 0.20, TreatmentPost 1.41 ± 0.16, PlaceboPre1.61 ± 0.51, PlaceboPost1.46 ± 0.56), or distance from center mass in centimeters (TreatmentPre 11.28 ± 4.28, TreatmentPost 11.92 ± 4.23, PlaceboPre10.52 ± 5.29, PlaceboPost10.94 ± 4.64). A significant time effect (P < 0.5) was found for both groups on all variables except distance from center mass. Reaction time values were adjusted to give percent decrease for initial reaction and mean reaction for the Treatment group (- 12.3% ± 16, - 15.2% ± 21.6) compared to the Placebo group (- 8.3% ± 21.8, - 12.5% ± 23.5), but no significant difference was found. CONCLUSION: The Alpha Brain® nootropic supplement did not have any statistically significant effects on marksmanship performance in this study. Given the rising popularity of nootropic supplements, future research on their potential impact on cognitively demanding soldier tasks, such as target discrimination scenarios, are recommended.

Fatty Acid Blood Levels, Vitamin D Status, Physical Performance, Activity, and Resiliency: A Novel Potential Screening Tool for Depressed Mood in Active Duty Soldiers.

This study examined whether blood fatty acid levels, vitamin D status, and/or physical activity are associated with physical fitness scores; a measure of mood, Patient Health Questionnaire-9; and a measure of resiliency, Dispositional Resiliency Scale-15 in active duty Soldiers. 100 active duty males at Fort Hood, Texas, underwent a battery of psychometric tests, anthropometric measurements, and fitness tests, and they also provided fasting blood samples for fatty acid and vitamin D analysis. Pearson bivariate correlation analysis revealed significant correlations among psychometric tests, anthropometric measurements, physical performance, reported physical inactivity (sitting time), and fatty acid and vitamin D blood levels. On the basis of these findings, a regression equation was developed to predict a depressed mood status as determined by the Patient Health Questionnaire-9. The equation accurately predicted depressed mood status in 80% of our participants with a sensitivity of 76.9% and a specificity of 80.5%. Results indicate that the use of a regression equation may be helpful in identifying Soldiers at higher risk for mental health issues. Future studies should evaluate the impact of exercise and diet as a means of improving resiliency and reducing depressed mood in Soldiers.

Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance.

BACKGROUND: Creatine monohydrate (CrM) and nitrate are popular supplements for improving exercise performance; yet have not been investigated in combination. We performed two studies to determine the safety and exercise performance-characteristics of creatine nitrate (CrN) supplementation. METHODS: Study 1 participants (N = 13) ingested 1.5 g CrN (CrN-Low), 3 g CrN (CrN-High), 5 g CrM or a placebo in a randomized, crossover study (7d washout) to determine supplement safety (hepatorenal and muscle enzymes, heart rate, blood pressure and side effects) measured at time-0 (unsupplemented), 30-min, and then hourly for 5-h post-ingestion. Study 2 participants (N = 48) received the same CrN treatments vs. 3 g CrM in a randomized, double-blind, 28d trial inclusive of a 7-d interim testing period and loading sequence (4 servings/d). Day-7 and d-28 measured Tendo™ bench press performance, Wingate testing and a 6x6-s bicycle ergometer sprint. Data were analyzed using a GLM and results are reported as mean ± SD or mean change ± 95 % CI. RESULTS: In both studies we observed several significant, yet stochastic changes in blood markers that were not indicative of potential harm or consistent for any treatment group. Equally, all treatment groups reported a similar number of minimal side effects. In Study 2, there was a significant increase in plasma nitrates for both CrN groups by d-7, subsequently abating by d-28. Muscle creatine increased significantly by d-7 in the CrM and CrN-High groups, but then decreased by d-28 for CrN-High. By d-28, there were significant increases in bench press lifting volume (kg) for all groups (PLA, 126.6, 95 % CI 26.3, 226.8; CrM, 194.1, 95 % CI 89.0, 299.2; CrN-Low, 118.3, 95 % CI 26.1, 210.5; CrN-High, 267.2, 95 % CI 175.0, 359.4, kg). Only the CrN-High group was significantly greater than PLA (p < 0.05). Similar findings were observed for bench press peak power (PLA, 59.0, 95 % CI 4.5, 113.4; CrM, 68.6, 95 % CI 11.4, 125.8; CrN-Low, 40.9, 95 % CI -9.2, 91.0; CrN-High, 60.9, 95 % CI 10.8, 111.1, W) and average power. CONCLUSIONS: Creatine nitrate delivered at 3 g was well-tolerated, demonstrated similar performance benefits to 3 g CrM, in addition, within the confines of this study, there were no safety concerns.

Effects of powdered Montmorency tart cherry supplementation on an acute bout of intense lower body strength exercise in resistance trained males.

BACKGROUND: The purpose of this study was to examine whether short-term ingestion of a powdered tart cherry supplement prior to and following intense resistance-exercise attenuates muscle soreness and recovery strength loss, while reducing markers of muscle damage, inflammation, and oxidative stress. METHODS: Twenty-three healthy, resistance-trained men (20.9 ± 2.6 yr, 14.2 ± 5.4% body fat, 63.9 ± 8.6 kg FFM) were matched based on relative maximal back squat strength, age, body weight, and fat free mass. Subjects were randomly assigned to ingest, in a double blind manner, capsules containing a placebo (P, n = 12) or powdered tart cherries [CherryPURE(®)] (TC, n = 11). Participants supplemented one time daily (480 mg/d) for 10-d including day of exercise up to 48-h post-exercise. Subjects performed ten sets of ten repetitions at 70% of a 1-RM back squat exercise. Fasting blood samples, isokinetic MVCs, and quadriceps muscle soreness ratings were taken pre-lift, 60-min, 24-h, and 48-h post-lift and analyzed by MANOVA with repeated measures. RESULTS: Muscle soreness perception in the vastus medialis (») (p = 0.10) and the vastus lateralis (») (p = 0.024) was lower in TC over time compared to P. Compared to pre-lift, TC vastus medialis (») soreness was significantly attenuated up to 48-h post-lift with vastus lateralis (») soreness significantly lower at 24-h post-lift compared to P. TC changes in serum creatinine (p = 0.03, delta p = 0.024) and total protein (p = 0.018, delta p = 0.006) were lower over time and smaller from pre-lift levels over time compared to P Significant TC group reductions from pre-lift levels were found for AST and creatinine 48-h post-lift, bilirubin and ALT 60-min and 48-h post-lift. No significant supplementation effects were observed for serum inflammatory or anti-inflammatory markers. None of the free radical production, lipid peroxidation, or antioxidant capacity markers (NT, TBARS, TAS, SOD) demonstrated significant changes with supplementation. Changes in TC whole blood lymphocyte counts (p = 0.013) from pre-lift were greater compared to P, but TC lymphocyte counts returned to pre-lift values quicker than P. CONCLUSION: Short-term supplementation of Montmorency powdered tart cherries surrounding a single bout of resistance exercise, appears to be an effective dietary supplement to attenuate muscle soreness, strength decrement during recovery, and markers of muscle catabolism in resistance trained individuals.