The Effect of Omega-3 Supplementation on Exercise-Induced Muscle Damage

Exercise-induced muscle damage (EIMD) results in transient muscle inflammation, strength loss, muscle soreness (Damas et al., 2016) and can result in subsequent exercise avoidance. Omega-3 (n-3) supplementation has been proposed to minimise EIMD via its anti-inflammatory properties (Jakeman et al., 2017), however its action remains unclear. We aimed to examine the effects of n-3 supplementation on exercise-induced inflammatory response following muscle-damaging exercise. Physically active, healthy Caucasian males (n = 14, 25.07 ± 4.05 years) provided written informed consent, then were single-blind randomised to either receive 3 g/day n-3 supplementation (N-3, n = 7) or placebo (PLA, n = 7). Following 4 weeks n-3 supplementation, a downhill running protocol (60 minutes at 65% V̇O2max, -10% gradient) was performed. Before supplementation (baseline), prior to EIMD, immediately after EIMD, and at 24, 48, and 72 hours post-EIMD, venous plasma was collected for creatine kinase (CK), interleukin (IL)-6 and tumour necrosis factor (TNF)-a, and maximal voluntary isometric contraction (MVIC), peak power (PP) and perceived muscle soreness were also quantified. Results are presented here as ‘median and interquartile range’ for CK, IL-6, TNF-a and perceived muscle soreness, and as ‘mean ± SD’ for MVIC and PP. Significant difference in CK activity was found between N-3 and PLA (p = 0.048) at 24 h post-EIMD, with PLA showing a larger increase in serum CK (baseline- vs 24h post-EIMD) compared to N-3 (677.4% vs 459.6%, respectively). PLA showed a larger increase in plasma IL-6 compared to N-3 immediately post-EIMD (143.9% vs 131.1%, respectively), however, there was no significant difference between groups at any time point (p > 0.05). TNF-a showed a smaller increase for the N-3 group compared to the PLA, again, there were no significant differences between groups at any time point (p > 0.05). Significant difference in muscle soreness was found between N-3 and PLA at 24 h post-EIMD (p = 0.034), with PLA showing a higher muscle soreness compared to N-3. A significant main effect for time was observed for MVIC with both groups showing a significant reduction in leg strength immediately post-EIMD. However, there were no significant differences between groups (p = 0.26) nor any group by time interactions (p = 0.90). A significant main effect for time was observed for PP, again, with PLA showing a larger reduction in PP at 24 h post-EIMD (pre- vs 24 h post-EIMD) compared to the N-3 (>96.6% vs N-3). However, there were no significant differences between groups (p = 0.31) nor any group by time interactions (p = 0.51). N-3 supplementation may attenuate EIMD, however, n-3 supplementation had no impact on muscle function nor power output. Even though we recorded some reduction in the inflammatory markers for the N-3 group, there was no statistically significant decrease to allow us to draw any definitive conclusions about the n-3 supplementation on exercise-induced muscle inflammation. Future studies might compare the dosage and duration of n-3 supplementation on muscle function or examine the effect of n-3 supplementation on EIMD during ageing-associated muscle function loss, where increased basal inflammation is seen

The Potential of Omega-3 Supplementation to Reduce Muscle-Inflammation after Muscle-Damaging Exercise

Muscle Damaging exercise (EIMD) induces inflammation and relates to strength loss, muscle-soreness and impaired recovery. Overall, this means a performance impairment which might be relevant for those who engages in competitions or strenuous physical activities. It remains unclear whether Omega-3 fatty acids (O-3) supplementation blunts the exercise-induced inflammation associated with EIMD and therefore prevents performance impairment. PURPOSE: Following a three-week supplementation with O-3, indirect markers of muscle damage were examined after a bout of EIMD to determine if supplementation had any beneficial effect in maintaining leg-strength levels. METHODS: Eight healthy, recreationally active caucasian males (28.13 ± 3.4 yr) were randomly allocated to a supplementation group (SUP, n = 4) to receive 2.85g/day O-3 supplementation or a control group (CON, n = 4) for three weeks. Following supplementation, participants performed a bout of EIMD, which consisted of performing 10 sets of 15 repetitions of leg extension at a self-assessed intensity of 7/10 on the Rate of Perceived Exertion scale. Creatine Kinase (CK) from venous blood samples, isometric right-leg strength, squat-jump test and perceived soreness were determined, as indirect markers of muscle-damage at Baseline, immediately after EIMD (POST) and 48 hours after EIMD to coincide with the delayed muscle inflammatory response. RESULTS: No statistically significant differences were found between Baseline and POST. There was a trend for smaller increase of CK levels (pre vs 48-h post EIMD) on the SUP group (38.8% increase) compared with the CON group (105.6% increase; P = 0.051). There was no significant effect (baseline vs. 48-h post EIMD) on muscle strength between SUP and CON group (P > 0.05), however, CON showed a larger decrease in strength compared to SUP (> 6.3% vs SUP). No differences in jump height were found between SUP and CON (P > 0.05). There was no significant difference in muscle soreness at 48-h post EIMD between SUP and CON group (P = 0.171). CONCLUSION: Three weeks of O-3 supplementation might decrease exercise-induced muscle inflammation after eccentric exercise. The lack of statistical significance may be adduced to the limitations of the study design and sample size. Supplementation with O-3 can be beneficial in athletes undergoing heavy exercise regimes and in sedentary individuals restarting physical activity, decreasing the exercise related muscle inflammation. The encouraging results from this pilot study have led to designing further work related to this topic

The effect of Omega-3 polyunsaturated fatty acid supplementation on exercise-induced muscle damage

Background Exercise-induced muscle damage (EIMD) results in transient muscle inflammation, strength loss, muscle soreness and may cause subsequent exercise avoidance. Omega-3 (n-3) supplementation may minimise EIMD via its anti-inflammatory properties, however, its efficacy remains unclear. Methods Healthy males (n = 14, 25.07 ± 4.05 years) were randomised to 3 g/day n-3 supplementation (N-3, n = 7) or placebo (PLA, n = 7). Following 4 weeks supplementation, a downhill running protocol (60 min, 65% V̇O2max, − 10% gradient) was performed. Creatine kinase (CK), interleukin (IL)-6 and tumour necrosis factor (TNF)-α, perceived muscle soreness, maximal voluntary isometric contraction (MVIC) and peak power were quantified pre, post, and 24, 48 and 72 h post-EIMD. Results Muscle soreness was significantly lower in N-3 vs PLA group at 24 h post-EIMD (p = 0.034). IL-6 was increased in PLA (p = 0.009) but not in N-3 (p = 0.434) following EIMD, however, no significant differences were noted between groups. Peak power was significantly suppressed in PLA relative to pre-EIMD but not in N-3 group at 24 h post-EIMD. However, no significant difference in peak power output was observed between groups. MVIC, CK and TNF-α were altered by EIMD but did not differ between groups. Conclusion N-3 supplementation for 4 weeks may successfully attenuate minor aspects of EIMD. Whilst not improving performance, these findings may have relevance to soreness-associated exercise avoidance

Relationships between hyperinsulinaemia, magnesium, vitamin D, thrombosis and COVID-19: rationale for clinical management

Risk factors for COVID-19 patients with poorer outcomes include pre-existing conditions: obesity, type 2 diabetes mellitus, cardiovascular disease (CVD), heart failure, hypertension, low oxygen saturation capacity, cancer, elevated: ferritin, C reactive protein (CRP) and D-dimer. A common denominator, hyperinsulinaemia, provides a plausible mechanism of action, underlying CVD, hypertension and strokes, all conditions typified with thrombi. The underlying science provides a theoretical management algorithm for the frontline practitioners. Vitamin D activation requires magnesium. Hyperinsulinaemia promotes: magnesium depletion via increased renal excretion, reduced intracellular levels, lowers vitamin D status via sequestration into adipocytes and hydroxylation activation inhibition. Hyperinsulinaemia mediates thrombi development via: fibrinolysis inhibition, anticoagulation production dysregulation, increasing reactive oxygen species, decreased antioxidant capacity via nicotinamide adenine dinucleotide depletion, haem oxidation and catabolism, producing carbon monoxide, increasing deep vein thrombosis risk and pulmonary emboli. Increased haem-synthesis demand upregulates carbon dioxide production, decreasing oxygen saturation capacity. Hyperinsulinaemia decreases cholesterol sulfurylation to cholesterol sulfate, as low vitamin D regulation due to magnesium depletion and/or vitamin D sequestration and/or diminished activation capacity decreases sulfotransferase enzyme SULT2B1b activity, consequently decreasing plasma membrane negative charge between red blood cells, platelets and endothelial cells, thus increasing agglutination and thrombosis. Patients with COVID-19 admitted with hyperglycaemia and/or hyperinsulinaemia should be placed on a restricted refined carbohydrate diet, with limited use of intravenous dextrose solutions. Degree/level of restriction is determined by serial testing of blood glucose, insulin and ketones. Supplemental magnesium, vitamin D and zinc should be administered. By implementing refined carbohydrate restriction, three primary risk factors, hyperinsulinaemia, hyperglycaemia and hypertension, that increase inflammation, coagulation and thrombosis risk are rapidly managed

Sprint interval training (SIT) reduces serum epidermal growth factor (EGF), but not other inflammatory cytokines in trained older men

Purpose The present study aimed to investigate the effect of age on circulating pro- and anti-inflammatory cytokines and growth factors. A secondary aim was to investigate whether a novel sprint interval training (SIT) intervention (3 × 20 s ‘all out’ static sprints, twice a week for 8 weeks) would affect inflammatory markers in older men. Methods Nine older men [68 (1) years] and eleven younger men [28 (2) years] comprised the younger group. Aerobic fitness and inflammatory markers were taken at baseline for both groups and following the SIT intervention for the older group. Results Interleukin (IL)-8, vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) were unchanged for the older and younger groups at baseline (IL-8, p = 0.819; MCP-1, p = 0.248; VEGF, p = 0.264). Epidermal growth factor (EGF) was greater in the older group compared to the younger group at baseline [142 (20) pg mL−1 and 60 (12) pg mL−1, respectively, p = 0.001, Cohen's d = 1.64]. Following SIT, older men decreased EGF to 100 (12) pg mL−1 which was similar to that of young men who did not undergo training (p = 0.113, Cohen's d = 1.07). Conclusion Older aerobically trained men have greater serum EGF than younger aerobically trained men. A novel SIT intervention in older men can shift circulating EGF towards trained younger concentrations. As lower EGF has previously been associated with longevity in C. elegans, the manipulative effect of SIT on EGF in healthy ageing in the human may be of further interest

Preliminary Investigations Into the Effect of Exercise-Induced Muscle Damage on Systemic Extracellular Vesicle Release in Trained Younger and Older Men

Background: Exercise-induced muscle damage (EIMD) results in transient muscle inflammation, strength loss, and muscle soreness and may cause subsequent exercise avoidance. Research has recently proven that skeletal muscle can also release extracellular vesicles (EVs) into the circulation following a bout of exercise. However, EV’s potential role, including as a biomarker, in the response to eccentric resistance exercise stimulus remains unclear. Methods: Twelve (younger, n=7, 27.0±1.5years and older, n=5, 63.0±1.0years) healthy, physically active males, undertaking moderate, regular physical activity (3–5 times per week) performed a unilateral high intensity eccentric exercise protocol. Venous plasma was collected for assessment of EVs and creatine kinase (CK) prior to EIMD, immediately after EIMD, and 1–72h post-EIMD, and maximal voluntary isometric contraction (MVIC) and delayed onset muscle soreness (DOMS) were assessed at all time points, except 1 and 2h post-EIMD. Results: A significant effect of both time (p=0.005) and group (pp=0.014) and in the older group (p=0.034) following EIMD, no significant differences were observed between groups. CK was not different between age groups but was altered following the EIMD (main effect of time p=0.026), with increased CK seen immediately post-, at 1 and 2h post-EIMD. EV count tended to be lower in older participants at rest, relative to younger participants (p=0.056), whilst EV modal size did not differ between younger and older participants pre-EIMD. EIMD did not substantially alter EV modal size or EV count in younger or older participants; however, the alteration in EV concentration (ΔCount) and EV modal size (ΔMode) between post-EIMD and pre-EIMD negatively associated with CK activity. No significant associations were noted between MVIC or DOMS and either ΔCount or ΔMode of EVs at any time point. Conclusion: These findings suggest that profile of EV release, immediately following exercise, may predict later CK release and play a role in the EIMD response. Exercise-induced EV release profiles may therefore serve as an indicator for subsequent muscle damage

How do MNC R&D laboratory roles affect employee international assignments?

Research and development (R&D) employees are important human resources for multinational corporations (MNCs) as they are the driving force behind the advancement of innovative ideas and products. International assignments of these employees can be a unique way to upgrade their expertise; allowing them to effectively recombine their unique human resources to progress existing knowledge and advance new ones. This study aims to investigate the effect of the roles of R&D laboratories in which these employees work on the international assignments they undertake. We categorise R&D laboratory roles into those of the support laboratory, the locally integrated laboratory and the internationally interdependent laboratory. Based on the theory of resource recombinations, we hypothesise that R&D employees in support laboratories are not likely to assume international assignments, whereas those in locally integrated and internationally interdependent laboratories are likely to assume international assignments. The empirical evidence, which draws from research conducted on 559 professionals in 66 MNC subsidiaries based in Greece, provides support to our hypotheses. The resource recombinations theory that extends the resource based view can effectively illuminate the international assignment field. Also, research may provide more emphasis on the close work context of R&D scientists rather than analyse their demographic characteristics, the latter being the focus of scholarly practice hitherto