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.

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.

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.