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Sirant LW, Singh J, Martin S, Gaul CA, Stuart-Hill L, Candow DG, Mang C, Neary JP. Long-term effects of multiple concussions on prefrontal cortex oxygenation during repeated squat-stands in retired contact sport athletes. Brain Inj 2022; 36:931-938. [PMID: 35968581 DOI: 10.1080/02699052.2022.2109737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND This study investigated the long-term effects of multiple concussions on prefrontal cortex oxygenation using near-infrared spectroscopy (NIRS) during a squat-stand maneuver that activated dynamic cerebral autoregulation. METHODS Active male retired contact sport athletes with a history of 3+ concussions (mTBI; n = 55), and active retired athletes with no concussion history (CTRL; n = 29) were recruited. Participants completed a 5-min squat-stand maneuve (10-s squat, 10-s stand, 0.05 Hz; 15 times). Oxygenated (O2Hb), deoxygenated (HHb), total (tHb) hemoglobin, and hemoglobin difference (HbDiff) were analyzed through the change in maximal and minimal values during the test (∆MAX), Z-scores, and standard deviations. RESULTS mTBI group showed left prefrontal cortex O2Hb ∆MAX (p = 0.046) and HbDiff ∆MAX (p = 0.018) were significantly higher. Within-group analyses showed significantly higher left HHb ∆MAX (p = 0.003) and lower left HbDiff Z-scores (p = 0.010) only in the mTBI group. The CTRL group demonstrated significantly lower left HbDiff SD (p = 0.039), tHb Z-scores (p = 0.030), and HbDiff ∆MAX (p = 0.037) compared to right prefrontal cortex response. CONCLUSION These preliminary results suggest changes in prefrontal cortex oxygenation potentially affecting the brain's ability to adapt to changing cerebral perfusion pressure after multiple previous concussions.
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Butchart S, Candow DG, Forbes SC, Mang CS, Gordon JJ, Ko J, Deprez D, Chilibeck PD, Ditor DS. Effects of Creatine Supplementation and Progressive Resistance Training in Stroke Survivors. INTERNATIONAL JOURNAL OF EXERCISE SCIENCE 2022; 15:1117-1132. [PMID: 35992184 PMCID: PMC9362889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The purpose was to investigate the effects of progressive resistance training (PRT) and creatine supplementation in stroke survivors. Participants were randomized to one of two groups: creatine (n = 5; 51 ± 16y) or placebo (n = 3; 73 ± 8y) during 10 weeks of supervised PRT. Prior to and following PRT and supplementation, assessments were made for body composition (lean tissue and fat mass), muscle thickness, muscle strength (1-repetition maximum), functional exercise capacity (6-minute walk test, Berg Balance Scale; BBS), cognition (Montreal Cognitive Assessment; MoCA), and symptoms of anxiety (Generalized Anxiety Disorder Assessment-7; GAD-7) and depression (Center for Epidemiological Studies Depression Scale; CES-D). There were time main effects for leg press strength (increased; p = 0.001), chest press strength (increased; p = 0.003), elbow flexor muscle thickness (increased; p = 0.007), BBS (increased; p = 0.002), MoCA (increased; p = 0.031) and CES-D (decreased; p = 0.045). There was a group x time interaction for the 6 minute walk test (p = 0.039). The creatine group significantly increased walking distance over time (p = 0.002) with no change in the placebo group (p = 0.120). Ten weeks of PRT had some positive effects on measures of muscle strength and size, balance, cognition and depression. The addition of creatine to PRT significantly improved walking performance in stroke survivors.
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Delpino FM, Figueiredo LM, Forbes SC, Candow DG, Santos HO. The Influence of Age, Sex, and Type of Exercise on the Efficacy of Creatine Supplementation on Lean Body Mass: A Systematic Review and Meta-analysis of Randomized Clinical Trials. Nutrition 2022; 103-104:111791. [DOI: 10.1016/j.nut.2022.111791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/06/2022] [Accepted: 06/27/2022] [Indexed: 10/31/2022]
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Giannos P, Prokopidis K, Forbes SC, Celoch K, Candow DG, Tartar JL. Gene Expression Changes of Murine Cortex Homeostasis in Response to Sleep Deprivation Hint Dysregulated Aging-like Transcriptional Responses. Brain Sci 2022; 12:825. [PMID: 35884632 PMCID: PMC9313387 DOI: 10.3390/brainsci12070825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 12/04/2022] Open
Abstract
Sleep deprivation leads to the deterioration in the physiological functioning of the brain, cognitive decline, and many neurodegenerative diseases, all of which progress with advancing age. Sleep insufficiency and impairments in cognitive function are characterized by progressive neuronal losses in the cerebral cortex. In this study, we analyze gene expression profiles following sleep-deprived murine models and circadian matched controls to identify genes that might underlie cortical homeostasis in response to sleep deprivation. Screening of the literature resulted in three murine (Mus musculus) gene expression datasets (GSE6514, GSE78215, and GSE33491) that included cortical tissue biopsies from mice that are sleep deprived for 6 h (n = 15) and from circadian controls that are left undisturbed (n = 15). Cortical differentially expressed genes are used to construct a network of encoded proteins that are ranked based on their interactome according to 11 topological algorithms. The analysis revealed three genes-NFKBIA, EZR, and SGK1-which exhibited the highest multi-algorithmic topological significance. These genes are strong markers of increased brain inflammation, cytoskeletal aberrations, and glucocorticoid resistance, changes that imply aging-like transcriptional responses during sleep deprivation in the murine cortex. Their potential role as candidate markers of local homeostatic response to sleep loss in the murine cortex warrants further experimental validation.
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Cornish SM, Cordingley DM, Shaw KA, Forbes SC, Leonhardt T, Bristol A, Candow DG, Chilibeck PD. Effects of Omega-3 Supplementation Alone and Combined with Resistance Exercise on Skeletal Muscle in Older Adults: A Systematic Review and Meta-Analysis. Nutrients 2022; 14:2221. [PMID: 35684018 PMCID: PMC9182791 DOI: 10.3390/nu14112221] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/21/2022] [Accepted: 05/24/2022] [Indexed: 12/21/2022] Open
Abstract
Sarcopenia negatively affects skeletal muscle mass and function in older adults. Omega-3 (ω-3) fatty acid supplementation, with or without resistance exercise training (RET), is suggested to play a role as a therapeutic component to prevent or treat the negative effects of sarcopenia. A systematic review and meta-analysis were conducted on the impact of ω-3 fatty acid supplementation with or without RET on measures of muscle mass and function in older adults (≥55 y). The data sources included SPORTDiscus, PubMed, and Medline. All the study types involving ω-3 fatty acid supplementation on measures of muscle mass and function in older adults (without disease) were included. The mean differences (MDs) or standardized mean differences (SMDs) with 95% confidence intervals were calculated and pooled effects assessed. Sixteen studies (1660 females, 778 males) met our inclusion criteria and were included in the meta-analysis. ω-3 fatty acid supplementation did not impact lean tissue mass (SMD 0.09 [-0.10, 0.28]). Benefits were observed for lower body strength (SMD 0.54 [0.33, 0.75]), timed-up-and-go (MD 0.29 [0.23, 0.35]s), and 30-s sit-to-stand performance (MD 1.93 [1.59, 2.26] repetitions) but not walking performance (SMD -0.01 [-0.10, 0.07]) or upper body strength (SMD 0.05 [-0.04, 0.13]). Supplementing with ω-3 fatty acids may improve the lower-body strength and functionality in older adults.
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Candow DG, Forbes SC, Roberts MD, Roy BD, Antonio J, Smith-Ryan AE, Rawson ES, Gualano B, Roschel H. Creatine O'Clock: Does Timing of Ingestion Really Influence Muscle Mass and Performance? Front Sports Act Living 2022; 4:893714. [PMID: 35669557 PMCID: PMC9163789 DOI: 10.3389/fspor.2022.893714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
It is well-established that creatine supplementation augments the gains in muscle mass and performance during periods of resistance training. However, whether the timing of creatine ingestion influences these physical and physiological adaptations is unclear. Muscle contractions increase blood flow and possibly creatine transport kinetics which has led some to speculate that creatine in close proximity to resistance training sessions may lead to superior improvements in muscle mass and performance. Furthermore, creatine co-ingested with carbohydrates or a mixture of carbohydrates and protein that alter insulin enhance creatine uptake. The purpose of this narrative review is to (i) discuss the purported mechanisms and variables that possibly justify creatine timing strategies, (ii) to critically evaluate research examining the strategic ingestion of creatine during a resistance training program, and (iii) provide future research directions pertaining to creatine timing.
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Arazi H, Aboutalebi S, Taati B, Cholewa JM, Candow DG. Effects of short-term betaine supplementation on muscle endurance and indices of endocrine function following acute high-intensity resistance exercise in young athletes. J Int Soc Sports Nutr 2022; 19:1-16. [PMID: 35599921 PMCID: PMC9116406 DOI: 10.1080/15502783.2022.2041988] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Objective This study examined the effects of short-term betaine supplementation on muscle endurance, plasma lactate, testosterone and cortisol levels, and the testosterone to cortisol (T/C) ratio in response to acute resistance exercise (RE). Method Using a double-blind, crossover study design, 10 handball players (age ± SD = 16 ± 1 yrs) without prior-structured RE experience performed a high-intensity RE session (leg press followed by bench press; 5 sets to volitional fatigue using 80% baseline 1 repetition maximum (1RM)), before and after 14 days of either placebo (maltodextrin) or betaine (2.5 g·d−1) supplementation. A 30-day washout period separated each treatment. 48 h prior to testing sessions, participants recorded their food intake and did not perform strenuous exercise. Venous blood was sampled before supplementation, and before and after each RE session. Results After betaine supplementation, participants performed more repetitions (p < 0.001) during the leg press (Betaine: 35.8 ± 4.3; Placebo: 24.8 ± 3.6, Cohen’s d = 2.77) and bench press (Betaine: 36.3 ± 2.6; Placebo: 26.1 ± 3.5, Cohen’s d = 3.34). Betaine resulted in lower post-exercise cortisol (Betaine: 7.6 ± 1.7; Placebo: 13 ± 3.4 µg.dL−1, p = 0.003, generalized eta squared (ηG2) = 0.49) and lactate (Betaine: 5.2 ± 0.3; Placebo: 6 ± 0.3 mmol.L−1, p < 0.001, ηG2 = 0.96) and higher total testosterone (Betaine: 15.2 ± 2.2; Placebo: 8.7 ± 1.7 ng.mL−1, p < 0.001, ηG2 = 0.87) and T/C ratio (Betaine: 0.21 ± 0.05; Placebo: 0.07 ± 0.02, p < 0.001, = 0.82). Conclusions Two weeks of betaine supplementation improved upper- and lower-body muscle endurance and influenced indices of endocrine function following an acute session of high-intensity RE in adolescent handball players.
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Grzyb K, Candow DG, Schoenfeld BJ, Bernat P, Butchart S, Neary JP. Effect of Equal Volume, High-Repetition Resistance Training to Volitional Fatigue, With Different Workout Frequencies, on Muscle Mass and Neuromuscular Performance in Postmenopausal Women. J Strength Cond Res 2022; 36:31-36. [PMID: 32028459 DOI: 10.1519/jsc.0000000000003422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Grzyb, K, Candow, DG, Schoenfeld, BJ, Bernat, P, Butchart, S, and Neary, JP. Effect of equal volume, high-repetition resistance training to volitional fatigue, with different workout frequencies, on muscle mass and neuromuscular performance in postmenopausal women. J Strength Cond Res 36(1): 31-36, 2022-This study examined the effects of equal volume, high-repetition resistance training (HRRT) performed to volitional fatigue, with different workout frequencies, on muscle mass and neuromuscular performance (strength, endurance) in untrained postmenopausal women. Subjects were randomized to perform HRRT 2 d·wk-1 (HRRT-2; 3 sets of 20-30 repetitions/set for elbow and knee flexion and extension) or 3 d·wk-1 (HRRT-3; 2 sets of 20-30 repetitions/set per exercise) for 8 weeks. Baseline and post-training assessments were made for muscle thickness, strength (1 repetition maximum [1RM]) and endurance (number of repetitions performed at 50% baseline 1RM) for elbow and knee flexor and extensor muscle groups. Significance was set at p < 0.05. There was a significant increase over time for all measures of muscle thickness, strength, and endurance (p < 0.005), with no differences between groups. Untrained postmenopausal women can expect to achieve similar improvements in muscle size, strength, and endurance when training 2 or 3 days per week, provided total weekly training volume is equal.
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Forbes SC, Ostojic SM, Souza-Junior TP, Candow DG. A high dose of creatine combined with resistance training appears to be required to augment indices of bone health in older adults. ANNALS OF NUTRITION AND METABOLISM 2021; 78:183-186. [PMID: 34788768 DOI: 10.1159/000520967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 11/19/2022]
Abstract
Not applicable.
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Ostojic SM, Forbes SC, Candow DG. Do Pregnant Women Consume Enough Creatine? Evidence from NHANES 2011-2018. ANNALS OF NUTRITION AND METABOLISM 2021; 78:114-116. [PMID: 34763333 DOI: 10.1159/000520818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 11/19/2022]
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Candow DG, Chilibeck PD, Gordon JJ, Kontulainen S. Efficacy of Creatine Supplementation and Resistance Training on Area and Density of Bone and Muscle in Older Adults. Med Sci Sports Exerc 2021; 53:2388-2395. [PMID: 34107512 DOI: 10.1249/mss.0000000000002722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To examine the efficacy of creatine (Cr) supplementation and any sex differences during supervised whole-body resistance training (RT) on properties of bone and muscle in older adults. METHODS Seventy participants (39 men, 31 women; mean age ± standard deviation: 58 ± 6 yr) were randomized to supplement with Cr (0.1 g·kg-1·d-1) or placebo (Pl) during RT (3 d·wk-1 for 1 yr). Bone geometry (radius and tibia) and muscle area and density (forearm and lower leg) were assessed using peripheral quantitative computed tomography. RESULTS Compared with Pl, Cr increased or maintained total bone area in the distal tibia (Cr, Δ +17 ± 27 mm2; Pl, Δ -1 ± 22 mm2; P = 0.031) and tibial shaft (Cr, Δ 0 ± 9 mm2; Pl, Δ -5 ± 7 mm2; P = 0.032). Men on Cr increased trabecular (Δ +28 ± 31 mm2; P < 0.001) and cortical bone areas in the tibia (Δ +4 ± 4 mm2; P < 0.05), whereas men on Pl increased trabecular bone density (Δ +2 ± 2 mg·cm-3; P < 0.01). There were no bone changes in the radius (P > 0.05). Cr increased lower leg muscle density (Δ +0.83 ± 1.15 mg·cm-3; P = 0.016) compared with Pl (Δ -0.16 ± 1.56 mg·cm-3), with no changes in the forearm muscle. CONCLUSIONS One year of Cr supplementation and RT had some favorable effects on measures of bone area and muscle density in older adults.
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dos Santos EEP, de Araújo RC, Candow DG, Forbes SC, Guijo JA, de Almeida Santana CC, do Prado WL, Botero JP. Efficacy of Creatine Supplementation Combined with Resistance Training on Muscle Strength and Muscle Mass in Older Females: A Systematic Review and Meta-Analysis. Nutrients 2021; 13:nu13113757. [PMID: 34836013 PMCID: PMC8619193 DOI: 10.3390/nu13113757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 12/15/2022] Open
Abstract
Sarcopenia refers to the age-related loss of muscle strength and muscle mass, which is associated with a reduced quality of life, particularly in older females. Resistance training (RT) is well established to be an effective intervention to counter indices of sarcopenia. Accumulating research indicates that the addition of creatine supplementation (Cr) to RT augments gains in muscle strength and muscle mass, compared to RT alone. However, some evidence indicates that sex differences may alter the effectiveness of Cr. Therefore, we systematically reviewed randomized controlled trials (RCTs) investigating the efficacy of Cr + RT on measures of upper- and lower-body strength and muscle mass in older females. A systematic literature search was performed in nine electronic databases. Ten RCTs (N = 211 participants) were included the review. Overall, Cr significantly increased measures of upper-body strength (7 studies, n = 142, p = 0.04), with no effect on lower-body strength or measures of muscle mass. Sub-analyses revealed that both upper-body (4 studies, n = 97, p = 0.05) and lower-body strength (4 studies, n = 100, p = 0.03) were increased by Cr, compared to placebo in studies ≥ 24 weeks in duration. In conclusion, older females supplementing with Cr experience significant gains in muscle strength, especially when RT lasts for at least 24 weeks in duration. However, given the level of evidence, future high-quality studies are needed to confirm these findings.
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Lixandrão ME, Longobardi I, Leitão AE, Morais JVM, Swinton PA, Aihara AY, Goes PCK, Ugrinowitsch C, Candow DG, Gualano B, Roschel H. Daily Leucine Intake Is Positively Associated with Lower Limb Skeletal Muscle Mass and Strength in the Elderly. Nutrients 2021; 13:nu13103536. [PMID: 34684538 PMCID: PMC8539207 DOI: 10.3390/nu13103536] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/30/2021] [Accepted: 10/06/2021] [Indexed: 01/03/2023] Open
Abstract
Higher daily protein intake, with an emphasis on leucine content, is thought to mitigate age-related anabolic resistance, potentially counteracting age-related morphological and functional declines. The present study investigated potential associations between total daily leucine intake and dependent variables, including quadriceps muscle cross-sectional area (CSA) and maximum dynamic muscle strength (1-RM) in a cohort of healthy free-living older individuals of both sexes (n = 67; 34/33 men/women). Participants performed three 24 h dietary recalls and underwent a magnetic resonance imaging exam followed by 1-RM tests. Our results demonstrate moderate associations between total daily leucine and both quadriceps CSA (r = 0.42; p = 0.004) and 1-RM (r = 0.45; p = 0.001). Furthermore, our exploratory biphasic linear regression analyses, adjusted for sex, age, and protein intake relative to body weight, revealed a plateau for daily leucine intake and muscle mass and muscle strength (~7.6–8.0 g·day−1) in older adults. In conclusion, we demonstrated that total daily leucine intake is associated with muscle mass and strength in healthy older individuals and this association remains after controlling for multiple factors, including overall protein intake. Furthermore, our breakpoint analysis revealed non-linearities and a potential threshold for habitual leucine intake, which may help guide future research on the effects of chronic leucine intake in age-related muscle loss.
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Forbes SC, Krentz JR, Candow DG. Timing of creatine supplementation does not influence gains in unilateral muscle hypertrophy or strength from resistance training in young adults: a within-subject design. J Sports Med Phys Fitness 2021; 61:1219-1225. [PMID: 34610729 DOI: 10.23736/s0022-4707.20.11668-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Creatine supplementation, in close proximity to resistance training sessions, may be an important strategy to augment muscle accretion and strength. The purpose of this study was to examine the effects of creatine supplementation immediately before compared to immediately after unilateral resistance training on hypertrophy and strength. METHODS Using a counter-balanced, double-blind, repeated measures within-subject design, ten recreationally active participants (7 males; 3 females; age: 23±5 years; height: 174±9 cm; body mass: 73.5±9.7 kg) were randomized to supplement with creatine monohydrate (0.1 g/kg of body mass) immediately before and placebo immediately after training one side of the body and placebo immediately before and creatine immediately after training the other side of the body on alternate days. Resistance training consisted of elbow flexion and knee extension (3-6 sets at 80% 1-repetition maximum [1-RM]) for 8 weeks. Prior to and following training, muscle thickness (elbow flexors and leg extensors; ultrasonography) and strength (1-RM for the elbow flexors and knee extensors) was assessed. RESULTS There was a significant increase over time for muscle thickness, strength, and relative strength (P<0.01), with no differences between creatine ingestion strategies. Total training volume performed was similar between conditions (P=0.56). CONCLUSIONS Creatine supplementation, immediately before or immediately after unilateral resistance training, produces similar gains in muscle hypertrophy and strength in young adults.
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Ruple BA, Godwin JS, Mesquita PHC, Osburn SC, Vann CG, Lamb DA, Sexton CL, Candow DG, Forbes SC, Frugé AD, Kavazis AN, Young KC, Seaborne RA, Sharples AP, Roberts MD. Resistance training rejuvenates the mitochondrial methylome in aged human skeletal muscle. FASEB J 2021; 35:e21864. [PMID: 34423880 DOI: 10.1096/fj.202100873rr] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/11/2022]
Abstract
Resistance training (RT) dynamically alters the skeletal muscle nuclear DNA methylome. However, no study has examined if RT affects the mitochondrial DNA (mtDNA) methylome. Herein, ten older, Caucasian untrained males (65 ± 7 y.o.) performed six weeks of full-body RT (twice weekly). Body composition and knee extensor torque were assessed prior to and 72 h following the last RT session. Vastus lateralis (VL) biopsies were also obtained. VL DNA was subjected to reduced representation bisulfite sequencing providing excellent coverage across the ~16-kilobase mtDNA methylome (254 CpG sites). Biochemical assays were also performed, and older male data were compared to younger trained males (22 ± 2 y.o., n = 7, n = 6 Caucasian & n = 1 African American). RT increased whole-body lean tissue mass (p = .017), VL thickness (p = .012), and knee extensor torque (p = .029) in older males. RT also affected the mtDNA methylome, as 63% (159/254) of the CpG sites demonstrated reduced methylation (p < .05). Several mtDNA sites presented a more "youthful" signature in older males after RT in comparison to younger males. The 1.12 kilobase mtDNA D-loop/control region, which regulates replication and transcription, possessed enriched hypomethylation in older males following RT. Enhanced expression of mitochondrial H- and L-strand genes and complex III/IV protein levels were also observed (p < .05). While limited to a shorter-term intervention, this is the first evidence showing that RT alters the mtDNA methylome in skeletal muscle. Observed methylome alterations may enhance mitochondrial transcription, and RT evokes mitochondrial methylome profiles to mimic younger men. The significance of these findings relative to broader RT-induced epigenetic changes needs to be elucidated.
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Lewgood J, Oliveira B, Korzepa M, Forbes SC, Little JP, Breen L, Bailie R, Candow DG. Efficacy of Dietary and Supplementation Interventions for Individuals with Type 2 Diabetes. Nutrients 2021; 13:2378. [PMID: 34371888 PMCID: PMC8308746 DOI: 10.3390/nu13072378] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 02/06/2023] Open
Abstract
The prevalence of Type 2 diabetes (T2D) is increasing, which creates a large economic burden. Diet is a critical factor in the treatment and management of T2D; however, there are a large number of dietary approaches and a general lack of consensus regarding the efficacy of each. Therefore, the purpose of this narrative review is twofold: (1) to critically evaluate the effects of various dietary strategies on diabetes management and treatment, such as Mediterranean diet, plant-based diet, low-calorie and very low-calorie diets, intermittent fasting, low-carbohydrate and very low-carbohydrate diets, and low glycemic diets and (2) to examine several purported supplements, such as protein, branched-chain amino acids, creatine, and vitamin D to improve glucose control and body composition. This review can serve as a resource for those wanting to evaluate the evidence supporting the various dietary strategies and supplements that may help manage T2D.
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Asbaghi O, Ashtary-Larky D, Bagheri R, Moosavian SP, Olyaei HP, Nazarian B, Rezaei Kelishadi M, Wong A, Candow DG, Dutheil F, Suzuki K, Alavi Naeini A. Folic Acid Supplementation Improves Glycemic Control for Diabetes Prevention and Management: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials. Nutrients 2021; 13:nu13072355. [PMID: 34371867 PMCID: PMC8308657 DOI: 10.3390/nu13072355] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/30/2021] [Accepted: 07/06/2021] [Indexed: 02/07/2023] Open
Abstract
Background: There is a growing interest in the considerable benefits of dietary supplementations, such as folic acid, on the glycemic profile. We aimed to investigate the effects of folic acid supplementation on glycemic control markers in adults. Methods: Randomized controlled trials examining the effects of folic acid supplementation on glycemic control markers published up to March 2021 were detected by searching online databases, including Scopus, PubMed, Embase, and ISI web of science, using a combination of related keywords. Mean change and standard deviation (SD) of the outcome measures were used to estimate the mean difference between the intervention and control groups at follow-up. Meta-regression and non-linear dose-response analysis were conducted to evaluate the association between pooled effect size and folic acid dosage (mg/day) and duration of the intervention (week). From 1814 detected studies, twenty-four studies reported fasting blood glucose (FBG), fasting insulin, hemoglobin A1C (HbA1C), and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) as an outcome measure. Results: Results revealed significant reductions in FBG (weighted mean difference (WMD): −2.17 mg/dL, 95% CI: −3.69, −0.65, p = 0.005), fasting insulin (WMD: −1.63 pmol/L, 95% CI: −2.53, −0.73, p < 0.001), and HOMA-IR (WMD: −0.40, 95% CI: −0.70, −0.09, p = 0.011) following folic acid supplementation. No significant effect was detected for HbA1C (WMD: −0.27%, 95% CI: −0.73, 0.18, p = 0.246). The dose-response analysis showed that folic acid supplementation significantly changed HOMA-IR (r = −1.30, p-nonlinearity = 0.045) in non-linear fashion. However, meta-regression analysis did not indicate a linear relationship between dose, duration, and absolute changes in FBG, HOMA-IR, and fasting insulin concentrations. Conclusions: Folic acid supplementation significantly reduces some markers of glycemic control in adults. These reductions were small, which may limit clinical applications for adults with type II diabetes. Further research is necessary to confirm our findings.
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Forbes SC, Candow DG, Ostojic SM, Roberts MD, Chilibeck PD. Meta-Analysis Examining the Importance of Creatine Ingestion Strategies on Lean Tissue Mass and Strength in Older Adults. Nutrients 2021; 13:nu13061912. [PMID: 34199420 PMCID: PMC8229907 DOI: 10.3390/nu13061912] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/26/2021] [Accepted: 05/30/2021] [Indexed: 12/25/2022] Open
Abstract
Creatine supplementation in conjunction with resistance training (RT) augments gains in lean tissue mass and strength in aging adults; however, there is a large amount of heterogeneity between individual studies that may be related to creatine ingestion strategies. Therefore, the purpose of this review was to (1) perform updated meta-analyses comparing creatine vs. placebo (independent of dosage and frequency of ingestion) during a resistance training program on measures of lean tissue mass and strength, (2) perform meta-analyses examining the effects of different creatine dosing strategies (lower: ≤5 g/day and higher: >5 g/day), with and without a creatine-loading phase (≥20 g/day for 5-7 days), and (3) perform meta-analyses determining whether creatine supplementation only on resistance training days influences measures of lean tissue mass and strength. Overall, creatine (independent of dosing strategy) augments lean tissue mass and strength increase from RT vs. placebo. Subanalyses showed that creatine-loading followed by lower-dose creatine (≤5 g/day) increased chest press strength vs. placebo. Higher-dose creatine (>5 g/day), with and without a creatine-loading phase, produced significant gains in leg press strength vs. placebo. However, when studies involving a creatine-loading phase were excluded from the analyses, creatine had no greater effect on chest press or leg press strength vs. placebo. Finally, creatine supplementation only on resistance training days significantly increased measures of lean tissue mass and strength vs. placebo.
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Pakulak A, Candow DG, Totosy de Zepetnek J, Forbes SC, Basta D. Effects of Creatine and Caffeine Supplementation During Resistance Training on Body Composition, Strength, Endurance, Rating of Perceived Exertion and Fatigue in Trained Young Adults. J Diet Suppl 2021; 19:587-602. [PMID: 33759701 DOI: 10.1080/19390211.2021.1904085] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The primary purpose was to determine the separate and combined effects of creatine and caffeine supplementation during resistance training on body composition and muscle performance in trained young adults. Twenty-eight participants were randomized to supplement with creatine and caffeine (CR-CAF; n = 9, 22 ± 4 years; 0.1 g·kg-1·d-1 of creatine monohydrate + 3 mg·kg-1·d-1 of caffeine anhydrous micronized powder); creatine (CR; n = 7, 22 ± 4 years, 0.1 g·kg-1·d-1 of creatine + 3 mg·kg-1·d-1 of micronized cellulose), caffeine (CAF; n = 6, 19 ± 1 years, 3 mg·kg-1·d-1 of caffeine + 0.1 g·kg-1·d-1 of maltodextrin) or placebo (PLA; n = 6, 23 ± 7 years, 0.1 g·kg-1·d-1 of maltodextrin + 3 mg·kg-1·d-1 micronized cellulose) one hour prior to performing resistance training for 6 weeks. Before and after training and supplementation, fat-free and fat mass (air-displacement plethysmography), muscle thickness (elbow and knee flexors and extensors; ultrasound), muscle strength (1-repetition maximum [1-RM] for the leg press and chest press), and endurance (one set of repetitions to volitional fatigue using 50% baseline 1-RM for leg press and chest press) were assessed. There was a group x time interaction (p = 0.049) for knee extensor muscle thickness with CR experiencing an increase over time with no changes in the other groups. There were no other between group differences for any variable. In conclusion, creatine supplementation and resistance training results in a small improvement in knee extensor muscle accretion in trained young adults.
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Pourabbas M, Bagheri R, Hooshmand Moghadam B, Willoughby DS, Candow DG, Elliott BT, Forbes SC, Ashtary-Larky D, Eskandari M, Wong A, Dutheil F. Strategic Ingestion of High-Protein Dairy Milk during a Resistance Training Program Increases Lean Mass, Strength, and Power in Trained Young Males. Nutrients 2021; 13:nu13030948. [PMID: 33804259 PMCID: PMC7999866 DOI: 10.3390/nu13030948] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/01/2021] [Accepted: 03/09/2021] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND We evaluated the effects of high-protein dairy milk ingestion on changes in body composition, strength, power, and skeletal muscle regulatory markers following 6 weeks of resistance training in trained young males. METHODS Thirty resistance-trained young males (age: 27 ± 3 years; training experience: 15 ± 2 months) were randomly assigned to one of two groups: high-protein dairy milk (both whey and casein) + resistance training (MR; n = 15) or isoenergetic carbohydrate (maltodextrin 9%) + resistance training (PR; n = 15). Milk and placebo were ingested immediately post-exercise (250 mL; 30 g protein) and 30 min before sleep (250 mL; 30 g protein). Before and after 6 weeks of linear periodized resistance training (4 times/week), body composition (bioelectrical impedance), strength, power, and serum levels of skeletal muscle regulatory markers (insulin-like growth factor 1 (IGF-1), growth hormone, testosterone, cortisol, follistatin, myostatin, and follistatin-myostatin ratio) were assessed. RESULTS The MR group experienced a significantly higher (p < 0.05) increase in lean mass, strength, and power (upper- and lower-body) than the PR group. Further, IGF-1, growth hormone, testosterone, follistatin, and follistatin-myostatin ratio were significantly increased, while cortisol and myostatin significantly decreased in the MR group than the PR group (p < 0.05). CONCLUSIONS The strategic ingestion of high-protein dairy milk (post-exercise and pre-sleep) during 6 weeks of resistance training augmented lean mass, strength, power, and altered serum concentrations of skeletal muscle regulatory markers in trained young males compared to placebo.
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Antonio J, Candow DG, Forbes SC, Gualano B, Jagim AR, Kreider RB, Rawson ES, Smith-Ryan AE, VanDusseldorp TA, Willoughby DS, Ziegenfuss TN. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr 2021; 18:13. [PMID: 33557850 PMCID: PMC7871530 DOI: 10.1186/s12970-021-00412-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/28/2021] [Indexed: 01/01/2023] Open
Abstract
Supplementing with creatine is very popular amongst athletes and exercising individuals for improving muscle mass, performance and recovery. Accumulating evidence also suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations. Furthermore, evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day). Although there are over 500 peer-refereed publications involving creatine supplementation, it is somewhat surprising that questions regarding the efficacy and safety of creatine still remain. These include, but are not limited to: 1. Does creatine lead to water retention? 2. Is creatine an anabolic steroid? 3. Does creatine cause kidney damage/renal dysfunction? 4. Does creatine cause hair loss / baldness? 5. Does creatine lead to dehydration and muscle cramping? 6. Is creatine harmful for children and adolescents? 7. Does creatine increase fat mass? 8. Is a creatine 'loading-phase' required? 9. Is creatine beneficial for older adults? 10. Is creatine only useful for resistance / power type activities? 11. Is creatine only effective for males? 12. Are other forms of creatine similar or superior to monohydrate and is creatine stable in solutions/beverages? To answer these questions, an internationally renowned team of research experts was formed to perform an evidence-based scientific evaluation of the literature regarding creatine supplementation.
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Odgers JB, Zourdos MC, Helms ER, Candow DG, Dahlstrom B, Bruno P, Sousa CA. Rating of Perceived Exertion and Velocity Relationships Among Trained Males and Females in the Front Squat and Hexagonal Bar Deadlift. J Strength Cond Res 2021; 35:S23-S30. [PMID: 33629974 DOI: 10.1519/jsc.0000000000003905] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Odgers, JB, Zourdos, MC, Helms, ER, Candow, DG, Dahlstrom, B, Bruno, P, and Sousa, CA. Rating of perceived exertion and velocity relationships among trained males and females in the front squat and hexagonal bar deadlift. J Strength Cond Res 35(2S): S23-S30, 2021-This study examined the accuracy of intraset rating of perceived exertion (RPE) to predict repetitions in reserve (RIR) during sets to failure at 80% of 1 repetition maximum (1RM) on the front squat and high-handle hexagonal bar deadlift (HHBD). Furthermore, the relationship between RPE and average concentric velocity (ACV) during the sets to failure was also determined. Fourteen males (29 ± 6 years, front squat relative 1RM: 1.78 ± 0.2 kg·kg-1, and HHBD relative 1RM: 3.0 ± 0.1 kg·kg-1) and 13 females (30 ± 5 years, front squat relative 1RM: 1.60 ± 0.2 kg·kg-1, and HHBD relative 1RM: 2.5 ± 0.3 kg·kg-1) visited the laboratory 3 times. The first visit tested 1RM on both exercises. During visits 2 and 3, which were performed in a counterbalanced order, subjects performed 4 sets to failure at 80% of 1RM for both exercises. During each set, subjects verbally indicated when they believed they were at "6" and "9" on the RIR-based RPE scale, and ACV was assessed during every repetition. The difference between the actual and predicted repetitions performed was recorded as the RPE difference (RPEDIFF). The RPEDIFF was significantly (p < 0.001) lower at the called 9 RPE versus the called 6 RPE in the front squat for males (9 RPE: 0.09 ± 0.19 versus 6 RPE: 0.71 ± 0.70) and females (9 RPE: 0.19 ± 0.36 versus 6 RPE: 0.86 ± 0.88) and in the HHBD for males (9 RPE: 0.25 ± 0.46 versus 6 RPE: 1.00 ± 1.12) and females (9 RPE: 0.21 ± 0.44 versus 6 RPE: 1.19 ± 1.16). Significant inverse relationships existed between RPE and ACV during both exercises (r = -0.98 to -1.00). These results indicate that well-trained males and females can gauge intraset RPE accurately during moderate repetition sets on the front squat and HHBD.
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Forbes SC, Candow DG, Ferreira LHB, Souza-Junior TP. Effects of Creatine Supplementation on Properties of Muscle, Bone, and Brain Function in Older Adults: A Narrative Review. J Diet Suppl 2021; 19:318-335. [PMID: 33502271 DOI: 10.1080/19390211.2021.1877232] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Aging is associated with reductions in muscle and bone mass and brain function, which may be counteracted by several lifestyle factors, of which exercise appears to be most beneficial. However, less than 20% of older adults (> 55 years of age) adhere to performing the recommended amount of resistance training (≥ 2 days/week) and less than 12% regularly meet the aerobic exercise guidelines (≥ 150 min/week of moderate to vigorous intensity aerobic exercise) required to achieve significant health benefits. Therefore, from a healthy aging and clinical perspective, it is important to determine whether other lifestyle interventions (independent of exercise) can have beneficial effects on aging muscle quality and quantity, bone strength, and brain function. Creatine, a nitrogen containing organic compound found in all cells of the body, has the potential to have favorable effects on muscle, bone, and brain health (independent of exercise) in older adults. The purpose of this narrative review is to examine and summarize the small body of research investigating the effects of creatine supplementation alone on measures of muscle mass and performance, bone mineral and strength, and indices of brain health in older adults.
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Sarshin A, Fallahi V, Forbes SC, Rahimi A, Koozehchian MS, Candow DG, Kaviani M, Khalifeh SN, Abdollahi V, Naderi A. Short-term co-ingestion of creatine and sodium bicarbonate improves anaerobic performance in trained taekwondo athletes. J Int Soc Sports Nutr 2021; 18:10. [PMID: 33478522 PMCID: PMC7819230 DOI: 10.1186/s12970-021-00407-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 01/05/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Creatine (CR) and sodium bicarbonate (SB) alone improve anaerobic performance. However, the ergogenic effects of CR and SB co-ingestion on taekwondo anaerobic performance remains unknown. METHODS Forty trained taekwondo athletes (21 ± 1 y.; 180.5 ± 7.3 cm; 72.7 ± 8.6 kg) were randomized to: (i) CR and SB (CR + SB; 20 g of CR+ 0.5 g·kg- 1·d- 1 of SB), (ii) CR, (iii) SB, (iv) placebo (PLA), or (v) control (CON) for 5 days. Before and after supplementation, participants completed 3 bouts of a Taekwondo Anaerobic Intermittent Kick Test (TAIKT) to determine changes in peak power (PP), mean power (MP), and fatigue index (FI). Blood lactate (BL) was measured before, immediately following, and 3 min post-TAIKT. RESULTS PP and MP increased over time (P < 0.05) following CR + SB, CR, and SB ingestion, with no changes in the PLA or CON groups. There was a greater increase over time in MP following CR + SB (Absolute Δ: 1.15 ± 0.28 W∙kg67) compared to CR (Absolute Δ: 0.43 ± 0.33 W∙kg67; P < 0.001) and SB (Absolute Δ: 0.73 ± 0.24 W∙kg67; P = 0.03). There were no significant time and condition effect for FI (P > 0.05). BL increased following exercise across all groups; however, CR + SB and SB post-exercise BL was lower compared to CR, PLA, and CON (P < 0.05). CONCLUSION Short-term CR and SB alone enhance TAIKT performance in trained taekwondo athletes. Co-ingestion of CR and SB augments MP compared to CR and SB alone, with similar PP improvements.
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Bagheri R, Hooshmand Moghadam B, Ashtary-Larky D, Forbes SC, Candow DG, Galpin AJ, Eskandari M, Kreider RB, Wong A. Whole Egg Vs. Egg White Ingestion During 12 weeks of Resistance Training in Trained Young Males: A Randomized Controlled Trial. J Strength Cond Res 2020; 35:411-419. [DOI: 10.1519/jsc.0000000000003922] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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