Nutritional Status and Daytime Pattern of Protein Intake on Match, Post-Match, Rest and Training Days in Senior Professional and Youth Elite Soccer Players

The nutritional status of elite soccer players across match, post-match, training and rest days has not been defined. Recent evidence suggests the pattern of dietary protein intake impacts the daytime turnover of muscle proteins and, as such, influences muscle recovery. We assessed the nutritional status and daytime pattern of protein intake in senior professional and elite youth soccer players and compared findings against published recommendations. Fourteen senior professional (SP) and fifteen youth elite (YP)soccer players fromtheDutch premier division completed nutritional assessments using a 24-h web-based recall method. Recall days consisted of a match, post-match, rest and training day. Daily energy intake over the 4-day period was similar between SP (2988±583 kcal/day) and YP (2938±465 kcal/day;p=0.800). Carbohydrate intake over the combined 4-day period was lower in SP (4.7±0.7 g·kg-1BM·day-1)vs.YP(6.0±1.5 g·kg-1BM·day-1,p=0.006) and SP failed to meet recommended carbohydrate intakes on match and training days. Conversely, recommended protein intakes were met for SP (1.9±0.3 g·kg-1BM·day-1) and YP (1.7±0.4 g·kg-1BM·day-1), with no differences between groups (p=0.286). Accordingly, both groups met or exceeded recommended daily protein intakes on individual match, post-match, rest and training days. A similar ‘balanced’ daytime pattern of protein intake was observed in SP and YP. To conclude, SP increased protein intake on match and training days to a greater extent than YP, however at the expense of carbohydrate intake. The daytime distribution of protein intake for YP and SP aligned with current recommendations of a balanced protein meal pattern

Aberrant Mitochondrial Homeostasis at the Crossroad of Musculoskeletal Ageing and Non-Small Cell Lung Cancer

Cancer cachexia is accompanied by muscle atrophy, sharing multiple common catabolic pathways with sarcopenia, including mitochondrial dysfunction. This study investigated gene expression from skeletal muscle tissues of older healthy adults, who are at risk of age-related sarcopenia, to identify potential gene biomarkers whose dysregulated expression and protein interference were involved in non-small cell lung cancer (NSCLC). Screening of the literature resulted in 14 microarray datasets (GSE25941, GSE28392, GSE28422, GSE47881, GSE47969, GSE59880 in musculoskeletal ageing; GSE118370, GSE33532, GSE19804, GSE18842, GSE27262, GSE19188, GSE31210, GSE40791 in NSCLC). Differentially expressed genes (DEGs) were used to construct protein-protein interaction (PPI) networks and 35 retrieve clustering gene modules. Overlapping module DEGs were ranked based on 11 topological algorithms and were correlated with prognosis, tissue expression, and tumour purity in NSCLC. The analysis revealed that the dysregulated expression of the mammalian mitochondrial ribosomal proteins, MRPS26, MRPS17, MRPL18, and MRPL51 were linked to reduced survival and tumour purity in NSCLC while tissue expression of the same genes followed an opposite direction in healthy older adults. These results support a potential link between the mitochondrial microenvironment in ageing muscle and NSLC. Further studies comparing changes in sarcopenia and NSCL associated cachexia are warranted

Handgrip strength is associated with learning and verbal fluency in older men without dementia: insights from the NHANES

Low handgrip strength, a hallmark measure of whole-body strength, has been linked with greater odds of cognitive decline and dementia however conflicting findings, which could be due to population characteristics, and choice of tools, such for the assessment of handgrip strength and cognitive function domains, also exits Therefore, we examined the relationship of handgrip strength with a comprehensive list of tests to assess domains of cognitive function using a representative sample of US older men and women without neurogenerative disorders such as dementia. We analysed cross sectional data from the US National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014, with a study cohort of 777 older adults (380 men and 397 women) above 60 years of age. Handgrip strength was assessed using a handgrip dynamometer, while cognitive function was assessed through the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test (WLLT), Word List Recall Test (WLRT), Intrusion Word Count Test (WLLT-IC and WLRT-IC), the Animal Fluency Test (AFT) and the Digit Symbol Substitution Test (DSST). Sex-stratified multiple linear regression analyses were performed upon covariate adjustment for age, ethnicity, socio-economic status, education, medical history, body mass index, physical activity, energy, protein, and alcohol intake. Maximal handgrip strength was positively associated with cognitive function scores, including CERAD WLLT (P=0.009, R2=0.146) and AFT (P=0.022, R2=0.024) in older men, but not in women (CERAD WLLT: P=0.253, AFT: P=0.370). No significant associations with CERAD WLLRT (men: P=0.057, women: P=0.976), WLLT-IC (men: P=0.671, women: P=0.869), WLLRT-IC (men: P=0.111, women: P=0.861), and DSST (men: P=0.108, women: P=0.091) were observed. Dose-response curves exhibited a prominent linear relationship between all significant associations after covariate adjustment, with no indication of a plateau in these relationships. In conclusion, higher handgrip strength was independently associated with better learning ability for novel verbal information and verbal fluency in US men over the age of 60 and without dementia. Longitudinal studies are required to confirm whether muscle strength independently predicts cognitive function changes in older adults in a sex specific manner, and whether this connection is affirmed to the possibility of reverse causation due to declines in physical activity levels in the preclinical phase of dementia

Resistance training increases skeletal muscle oxidative capacity and net intramuscular triglyceride breakdown in type I and II fibres of sedentary males

New Findings What is the central question of this study? Recent research from our laboratory, supported by in vitro effects of perilipins, suggested that improvements in insulin sensitivity following endurance training are mechanistically linked to increases in muscle oxidative capacity, intramuscular triglyceride utilization during moderate endurance exercise and increases in the content of the lipid droplet-associated perilipins 2 and 5. This study aimed to investigate whether these adaptations also occur in response to resistance training. What is the main finding and its importance? Six weeks of resistance training increased all the mentioned variables. These novel data suggest that improvements in muscle oxidative capacity and lipid metabolism contribute to the increase in insulin sensitivity following resistance training. Recent in vitro and in vivo experimental observations suggest that improvements in insulin sensitivity following endurance training are mechanistically linked to increases in muscle oxidative capacity, intramuscular triglyceride (IMTG) utilization during endurance exercise and increases in the content of the lipid droplet-associated perilipin2 (PLIN2) and perilipin5 (PLIN5). This study investigated the hypothesis that similar adaptations may also underlie the resistance training (RT)-induced improvements in insulin sensitivity. Thirteen sedentary men (20±1years old; body mass index 24.8±0.8kgm-2) performed 6weeks of whole-body RT (three times per week), and changes in peak O2 uptake (in millilitres per minute per kilogram) and insulin sensitivity were assessed. Muscle biopsies (n=8) were obtained before and after 60min steady-state cycling at ∼65% peak O2 uptake. Immunofluorescence microscopy was used to assess changes in oxidative capacity (measured as cytochrome c oxidase protein content), IMTG and PLIN2 and PLIN5 protein content. Resistance training increased peak O2 uptake (by 8±3%), COX protein content (by 46±13 and 61±13% in type I and II fibres, respectively) and the Matsuda insulin sensitivity index (by 47±6%; all P<0.05). In typeI fibres, IMTG (by 52±11%; P<0.05) and PLIN2 content (by 107±19%; P<0.05) were increased and PLIN5 content tended to increase (by 54±22%; P=0.054) post-training. In typeII fibres, PLIN2 content increased (by 57±20%; P<0.05) and IMTG (by 46±17%; P=0.1) and PLIN5 content (by 44±24%; P=0.054) tended to increase post-training. Breakdown of IMTG during moderate-intensity exercise was greater in both typeI and typeII fibres (by 43±5 and 37±5%, respectively; P<0.05) post-RT. The results confirm the hypothesis that RT enhances muscle oxidative capacity and increases IMTG breakdown and the content of PLIN2 and PLIN5 in both typeI and typeII fibres during endurance-type exercise

Impact of probiotics on muscle mass, muscle strength, and lean body mass: a systematic review and meta-analysis Journal of Cachexia, Sarcopenia and Muscle

Probiotics have shown potential to counteract sarcopenia, although the extent to which they can influence domains of sarcopenia such as muscle mass and strength in humans is unclear. The aim of this systematic review and meta‐analysis was to explore the impact of probiotic supplementation on muscle mass, total lean mass and muscle strength in human adults. A literature search of randomized controlled trials (RCTs) was conducted through PubMed, Scopus, Web of Science and Cochrane Library from inception until June 2022. Eligible RCTs compared the effect of probiotic supplementation versus placebo on muscle and total lean mass and global muscle strength (composite score of all muscle strength outcomes) in adults (>18 years). To evaluate the differences between groups, a meta‐analysis was conducted using the random effects inverse‐variance model by utilizing standardized mean differences. Twenty‐four studies were included in the systematic review and meta‐analysis exploring the effects of probiotics on muscle mass, total lean mass and global muscle strength. Our main analysis (k = 10) revealed that muscle mass was improved following probiotics compared with placebo (SMD: 0.42, 95% CI: 0.10–0.74, I(2) = 57%, P = 0.009), although no changes were revealed in relation to total lean mass (k = 12; SMD: ‐0.03, 95% CI: −0.19 – 0.13, I(2) = 0%, P = 0.69). Interestingly, a significant increase in global muscle strength was also observed among six RCTs (SMD: 0.69, 95% CI: 0.33–1.06, I(2) = 64%, P = 0.0002). Probiotic supplementation enhances both muscle mass and global muscle strength; however, no beneficial effects were observed in total lean mass. Investigating the physiological mechanisms underpinning different ageing groups and elucidating appropriate probiotic strains for optimal gains in muscle mass and strength are warranted

Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men

Background: Adequate protein ingestion-mediated stimulation of myofibrillar protein synthesis (MPS) is required to maintain skeletal muscle mass. It is currently unknown what per meal protein intake is required to maximally stimulate the response in older men and whether it differs from that of younger men. Methods: We retrospectively analyzed data from our laboratories that measured MPS in healthy older (~71 years) and younger (~22 years) men by primed constant infusion of L-ring-[13C6]phenylalanine after ingestion of varying amounts (0–40 g) of high-quality dietary protein as a single bolus and normalized to body mass and, where available, lean body mass (LBM). Results: There was no difference (p = .53) in basal MPS rates between older (0.027±0.04%/h; means ± 95% CI) and young (0.028 ± 0.03%/h) men. Biphase linear regression and breakpoint analysis revealed the slope of first line segment was lower (p < .05) in older men and that MPS reached a plateau after ingestion of 0.40 ± 0.19 and 0.24 ± 0.06 g/kg body mass (p= .055) and 0.60 ± 0.29 and 0.25 ± 0.13 g/kg lean body mass (p < .01) in older and younger men, respectively. Conclusions: This is the first report of the relative (to body weight) protein ingested dose response of MPS in younger and older men. Our data suggest that healthy older men are less sensitive to low protein intakes and require a greater relative protein intake, in a single meal, than young men to maximally stimulate postprandial rates of MPS. These results should be considered when developing nutritional solutions to maximize MPS for the maintenance or enhancement of muscle mass with advancing age