Tracey Matthews

Effects of betaine on body composition, performance, and homocysteine thiolactone

BackgroundThis study investigated the effects of long term betaine supplementation on body composition, performance, and homocysteine thiolactone (HCTL) in experienced strength trained men.MethodsTwenty-three subjects were matched for training experience (4.8 ± 2.3 years) and body fat percentage (BF%: 16.9 ± 8.0%), randomly assigned to either a placebo (PL; n = 12) or betaine group (BET; n = 11; 2.5 g/day), and completed a 6 week periodized training program consisting of 3 two-week micro-cycles. Bench press and back squat training volumes were recorded and changes in training volume were assessed at each micro-cycle. Fasting urine was collected at baseline (BL), weeks 2, 4 and 6, and assayed for HCTL. Subjects were tested prior to and following 6 weeks of treatment. Arm and thigh cross sectional area (CSA) was estimated via girth and skin fold measurements. Body density was estimated via skin fold calipers and used to estimate BF%, fat mass (FM), and lean body mass (LBM). Performance was assessed via vertical jump (VJ), bench press 1 RM (BP), and back squat 1 RM (BS).ResultsArm CSA increased significantly (p < .05) in BET but not PL. No differences existed between group and time for changes in thigh CSA. Back squat training volume increased significantly (p < .05) for both groups throughout training. Bench press training volume was significantly (p < .05) improved for BET compared to PL at microcycles one and three. Body composition (BF%, FM, LBM) improved significantly (p < .05) in BET but not PL. No differences were found in performance variables (BP, BS, VJ) between groups, except there was a trend (p = .07) for increased VJ power in BET versus PL. A significant interaction (p < .05) existed for HCTL, with increases from BL to week 2 in PL, but not BET. Additionally, HCTL remained elevated at week 4 in PL, but not BET.ConclusionSix-weeks of betaine supplementation improved body composition, arm size, bench press work capacity, attenuated the rise in urinary HCTL, and tended to improve power (p = .07) but not strength.

Effects of a short-term carbohydrate-restricted diet on strength and power performance.

Abstract Sawyer, JC, Wood, RJ, Davidson, PW, Collins, SM, Matthews, TD, Gregory, SM, and Paolone, VJ. Effects of a short-term carbohydrate-restricted diet on strength and power performance. J Strength Cond Res 27(8): 2255–2262, 2013—The purpose of the study was to examine the effects of switching from a habitual diet to a carbohydrate-restricted diet (CRD) on strength and power performance in trained men (n = 16) and women (n = 15). Subjects performed handgrip dynamometry, vertical jump, 1RM bench press and back squat, maximum-repetition bench press, and a 30-second Wingate anaerobic cycling test after consuming a habitual diet (40.7% carbohydrate, 22.2% protein, and 34.4% fat) for 7 days and again after following a CRD (5.4% carbohydrate, 35.1% protein, and 53.6% fat) for 7 days. Before both testing sessions, body weight and composition were examined using bioelectrical impedance analysis. Three 2 × 2 multiple analyses of variance were used to compare performance variables between the habitual diet and CRD. Subjects consumed significantly fewer (p < 0.05) total kilocalories during the CRD (2,156.55 ± 126.7) compared with the habitual diet (2,537.43 ± 99.5). Body mass decreased significantly (p < 0.05). Despite a reduction in body mass, strength and power outputs were maintained for men and women during the CRD. These findings may have implications for sports that use weight classes, and in which strength and power are determinants of success. A CRD may be an alternative method for short-term weight loss without compromising strength and power outputs. The use of a 7-day CRD could replace weight loss methods employing severe dehydration before competition.

Acute effects of a cluster-set protocol on hormonal, metabolic and performance measures in resistance-trained males

Abstract Limited research exists on rest-pause or cluster-set (CS) protocols. Acute effects of a traditional set (TS) and CS protocols of resistance exercise on serum growth hormone (GH), cortisol (C), blood lactate (BL), countermovement vertical jump (CMVJ) and standing long jump (SLJ) were compared. Eleven resistance-trained males (22.9±2.6 year; 176.9±10.6 cm; 78.5±1.6 kg; 12.9±3.1% BF) completed one repetition maximum tests for clean pull (CP), back squat (BS) and bench press (BP). Subjects were then randomly assigned to TS or CS protocols for sessions 2 and 3, and performed CP and BS lifts followed by two circuits of three sets of three exercises. GH, C, BL, CMVJ and SLJ were measured pre-exercise (Pre), mid-exercise following completion of CS or TS protocol (Mid), immediately (IP), 15 (15P) and 30 (30P) minutes post-exercise. Repeated measures ANOVAs examined differences in GH, C, BL, CMVJ and SLJ. No differences (p>0.05) existed between protocols for GH and C. GH levels 15P were elevated (p<0.05) above 30P (15.78 + 4.66 vs. 12.10 + 4.66 µg.L−1). C levels 30P were elevated (p<0.05) above Pre (716.85 + 102.56 vs. 524.79 + 75.79 nmol.L−1). Interaction (p <0.05) existed between protocol and time for BL; mid-BL was lower for CS than TS (7.69±3.73 vs. 12.78±1.90 mmol.L−1). Pooled data for CMVJ and SLJ were greater (p <0.05) across the CS protocol. The less metabolically taxing CS protocol resulted in better sustainability of jump measures.

Preservation of Fat-Free Mass After Two Distinct Weight Loss Diets with and without Progressive Resistance Exercise

BACKGROUND Preserving fat-free mass (FFM) during weight loss is important in older adults. The purpose was to examine a low-fat diet (LFD) versus a carbohydrate-restricted diet (CRD) with and without progressive resistance exercise (PRE) on preservation of FFM in older men with metabolic syndrome. METHODS A total of 42 men (59±7 years) were matched [body mass index (BMI)] and randomized to LFD, LFD&PRE, CRD, and CRD&PRE. PRE groups performed supervised strength training three times per week. Body weight, composition, metabolic syndrome criteria, and strength were measured at baseline and week 12. A 3-day diet record was kept at baseline and at weeks 1, 6, and 12. RESULTS Attrition (24%) was similar between groups. Depicted as % carbohydrate:fat:protein, the intervention diet was: LFD=55:24:18, LFD&PRE=57:20:20, CRD=16:54:28, and CRD&PRE=12:56:31. Weight (lb) decreased similarly in all groups (LFD, -18.0±7.4; LFD&PRE, -19.8±12.8; CRD, -20.2±8.0; CRD&PRE, -22.7±6.0; P<0.001), and number of participants with metabolic syndrome decreased in all groups (-3, -6, -3, -4, respectively). Percent of weight loss from appendicular FFM was 27.5%, 15.9%, 15.7%, and 17.3% respectively. A trend was found when comparing LFD and LFD&PRE (P=0.068), and when comparing LFD&CRD (P=0.072). Triglycerides improved more for the LFD&PRE, CRD, and CRD&PRE groups compared to the LFD group (P<0.05). Improvements in high-density lipoprotein-cholesterol were better in the CRD&PRE group (4.1±5.1 mg/dL) versus the LFD group (-5.0±5.9 mg/dL; P<0.01). CONCLUSIONS LFD&PRE, CRD, and CRD&PRE preserve FFM similarly. PRE is an important component of a LFD during weight loss in this population.

Motivational differences for participation among championship and non-championship caliber NCAA division III football teams.

Abstract Blegen, MD, Stenson, MR, Micek, DM, and Matthews, TD. Motivational differences for participation among championship and non-championship caliber NCAA division III football teams. J Strength Cond Res 26(11): 2924–2928. 2012—Reasons for participation in National Collegiate Athletic Association (NCAA) Division III athletics vary greatly. The purpose of this study was to investigate if differences in motivational climate existed between championship and non–championship-level NCAA Division III football teams, and differences in player status (starter vs. nonstarter). Players (N = 224) from 3 NCAA Division III football programs (1 championship level and 2 non-championship level) were recruited as participants. All players completed the Sport Motivation Scale, and the results were analyzed using a 2 × 2 multivariate analysis of variance (MANOVA) to examine differences among the motivation variables for starter vs. nonstarter and championship vs. non-championship teams. A 1-way MANOVA was used to examine differences across year in school. Dependent variables included internal motivation to experience stimulation, internal motivation for accomplishment, internal motivation for knowledge, external motivation for identification regulation, external motivation for introjection regulation, external motivation for external regulation, and amotivation. The interaction between starter status and team was not significant (&Lgr; = 0.996, p > 0.40). Additionally, there were no significant differences in the mean vector scores for starter vs. nonstarter (&Lgr; = 0.965, p = 0.378). For team type, however, differences did exist across dependent variables (&Lgr; = 0.898, p = 0.002). For all variables except amotivation, the championship-level team had significantly higher scores than the non–championship-level teams. Members of NCAA Division III championship-level football teams have higher motivation to participate in their sport compared with members of non-championship teams. These results could have an impact on player morale, coaching strategies, and future success in athletic-related activities.

Measurement in Physical Education and Exercise Science: A Brief Report on 2015 and Calls for Manuscripts in 2016 and Beyond

In June 2015, Eddie Lam completed his second term as Editor-in-Chief forMeasurement in Physical Education and Exercise Science (MPEES). We thank Eddie for his service and we look forward to his continued contributions to MPEES as a member of the Editorial Board. In July 2015, I, Nicholas Myers, began a 3-year term as Editor-in-Chief forMPEESwithTraceyD.Matthews continuing asChair of the Editorial Board. The purposes of this editorial are to: (a) provide a summary ofMPEES-related activities in 2015 and (b) share some ideas for MPEES-related activities in 2016 and beyond. Before proceeding directly toward both of these purposes, however, a summary of the mission, scope, and aim ofMPEES is provided. The mission of MPEES is to increase both the quality and the amount of measurement research being conducted in physical education and exercise science. The scope of MPEES covers original measurement research, special issues, and tutorials within six substantive disciplines of physical education and exercise science. Six of the seven sections of MPEES define the substantive disciplines within the purview of the original research to be published in the journal: Exercise Science, Physical Activity, Physical Education Pedagogy, Psychology, Research Methodology and Statistics, and Sport Management and Administration. The seventh section of MPEES, Tutorial and Teacher’s Toolbox, serves to provide an outlet for review and/or didactic manuscripts to be published in the journal. Special issues provide an avenue for a coherent set of manuscripts (e.g., four to five) to collectively focus in-depth on an important and timely measurement-related issue within the scope of MPEES. The primary aim of MPEES is to publish high-impact manuscripts, most of which will focus on original research, that fit within the scope of the journal. Full information on all operating guidelines for MPEES (e.g., mission, scope, and aims) are available by request to Thomas Lawson (TLawson@shapeamerica.org). MPEES-related activities in 2015

Measurement in Physical Education and Exercise Science (MPEES): A Reflection on 20 Years of Publications and a Brief Report on 2016

This editorial has two purposes that are addressed in the two major sections of this article. The first major section of this editorial provides a reflection on 20 years of publications in MPEES and follows a decennial tradition started by Yuanlong Liu (2007). Tracey Matthews, the current Chair of the Editorial Board of MPEES, provided the content for the first major section of this article. The second major section of this editorial provides a summary of MPEES-related activities in 2016 and serves to update the most recent 2015 annual review provided by Myers, Matthews, and Park (2016). Nicholas Myers, the current Editor-in-Chief of MPEES, and Seungmin Lee provided the content for the second major section of this article.

Influence of Sustained Beta-Alanine Supplementation on Body Composition and Physical Performance in College-aged Males Seeking Military Commission

The present study was designed to investigate the effects of chronic ingestion of a proprietary beta-alanine supplement on body composition, indices of strength and power performance, and markers of cardiovascular endurance in physically active, college-aged males commissioning within the armed services. Subjects (n = 30) participated in four separate testing sessions, both pre and post assessment consuming either 6.0 g/day beta-alanine or Placebo supplementation for 6 weeks. Parameters evaluated included body fat percentage (BF%), fat free mass (FFM), vertical jump (VJ), 1 repetition maximum back squat (SQ) and bench press (BP), and a repetition maximum bench press (RMBP) at 75% of the attained maximum, maximal oxygen consumption (VO2peak), respiratory exchange ratio (RER), lactate threshold (LT), and peak lactate concentration. For all variables, no significant interactions existed across condition and time (p > .05). In addition, for all variables, no significant differences existed between conditions (p > .05). Beta-alanine did not show any benefit for improving body composition or physical performance parameters in this group of individuals.

Changes in Sitting Time and Sitting Fragmentation after a Workplace Sedentary Behaviour Intervention

Prolonged sedentary behaviour (SB) has shown to be detrimental to health. Nevertheless, population levels of SB are high and interventions to decrease SB are needed. This study aimed to explore the effect of a personalized intervention aimed at reducing SB and increasing breaks in SB among college employees. A pre-experimental study design was used. Participants (n = 36) were recruited at a college in Massachusetts, USA. SB was measured over 7 consecutive days using an activPAL3 accelerometer. Following baseline measures, all participants received a personalized SB consultation which focused on limiting bouts of SB >30 min, participants also received weekly follow-up e-mails. Post-intervention measures were taken after 16 weeks. Primary outcome variables were sedentary minutes/day and SB bouts >30 min. Differences between baseline and follow-up were analyzed using paired t-tests. The intervention did not change daily sedentary time (−0.48%; p > 0.05). The number of sedentary bouts >30 min decreased significantly by 0.52 bouts/day (p = 0.010). In this study, a personalized SB intervention was successful in reducing number of bouts >30 min of SB. However, daily sedentary time did not reduce significantly. These results indicate that personalized, consultation-based interventions may be effective if focused on a specific component of SB.

The Effects Of An Acute Bout Of Self-myofascial Release On The Physiological Parameters Of Running: 3473 Board #234 May 30, 8

This study examined changes in the physiological parameters of running performance when self-myofascial release (SMR) was used prior to a submaximal run. A total of 16 male recreational runners, between the ages of 27 and 50 years old volunteered for the study. Participants had to complete a running event measuring a 10K or longer in the past 12 months and obtained a V̇O2peak value of 45 mL·kg-l · min-1 to be included in the study. Participants took part in two 40 min treadmill runs at 75% of their V̇O2peak, one session with the use of SMR and the other with 20 min of seated rest prior to the run. Measurements of heart rate, blood lactate concentrations, ventilatory efficiency (V̇E/ V̇O2), RPE, and running velocity were assessed. There was no statistically significant interaction or treatment effect for these variables when SMR was used prior to a 40 min treadmill run (p > .05; heart rate: d = .01, V̇E/ V̇O2: d = .07, RPE: d = .07). Although no positive effects on running performance were found, the lack of negative effects suggests the use of SMR prior to running does not hinder performance.