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1.
Death Stud ; 45(9): 677-691, 2021.
Article in English | MEDLINE | ID: mdl-31608784

ABSTRACT

The authors present the development and validation of the Coping Assessment for Bereavement and Loss Experiences (CABLE), the first instrument designed to assess a range of potentially constructive strategies for coping with grief following the death of a loved one. Exploratory and confirmatory factor analysis with an international sample of bereaved adults (N = 844) yielded a six-factor, 28-item structure. Use of this validated, clinically useful, self-report tool can inform clinicians and researchers in evaluating bereavement coping, and in developing interventions designed to increase the number and broaden the types of coping strategies used to facilitate healing following loss.


Subject(s)
Bereavement , Adaptation, Psychological , Adult , Factor Analysis, Statistical , Grief , Humans
2.
Muscle Nerve ; 55(3): 344-349, 2017 03.
Article in English | MEDLINE | ID: mdl-27422091

ABSTRACT

INTRODUCTION: The purpose of this study was to determine the validity of the maximal distance-electromyography (Dmax-EMG) method for estimating physical working capacity at fatigue threshold (PWCFT ). METHODS: Twenty-one men and women (age 22.9 ± 3.0 years) volunteered to perform 12 sessions of high-intensity interval training (HIIT) over 4 weeks. Before and after HIIT training, a graded exercise test (GXT) was used to estimate PWCFT using the Dmax method and the original (ORG) method. RESULTS: There was a significant increase in PWCFT for both ORG (+10.6%) and Dmax (+12.1%) methods, but no significant difference in the change values between methods. Further, Bland-Altman analyses resulted in non-significant biases (ORG-Dmax) between methods at pre-HIIT (-6.4 ± 32.5 W; P > 0.05) and post-HIIT (-4.2 ± 33.1 W; P > 0.05). CONCLUSION: The Dmax method is sensitive to training and is a valid method for estimating PWCFT in young men and women. Muscle Nerve 55: 344-349, 2017.


Subject(s)
Exercise/physiology , Muscle Fatigue/physiology , Physical Education and Training , Work Capacity Evaluation , Adult , Analysis of Variance , Electromyography , Exercise Test , Female , Healthy Volunteers , Humans , Male , Physical Examination , Young Adult
3.
Eur J Appl Physiol ; 116(9): 1663-70, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27333913

ABSTRACT

PURPOSE: To examine the mitogen-activated protein kinase (MAPK) family of signaling proteins following typical high volume (HV) and high intensity (HI) lower body resistance exercise protocols in resistance-trained men. METHODS: Ten resistance-trained men (24.7 ± 3.4 year; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. The HV protocol utilized a load of 70 % 1-RM for sets of 10-12 repetitions with a 1-min rest period length between sets and exercises. The HI protocol utilized a load of 90 % 1-RM for sets of 3-5 repetitions with a 3-min rest period length between sets and exercises. Both protocols included six sets of barbell back squats and four sets of bilateral leg press, bilateral hamstring curls, bilateral leg extensions, and seated calf raises. Fine needle muscle biopsies of the vastus lateralis were completed at baseline (BL) and 1-h post exercise (1H). RESULTS: No significant differences over time were noted for phosphorylation of MEK1, ERK1/2, p38, MSK1, ATF2, p53, or c-Jun (p > 0.05). No significance between trial interactions was noted for phosphorylation of MAPK signaling proteins, including MEK1, ERK1/2, p38, JNK, MSK1, ATF2, STAT1, p53, c-Jun, or HSP27 (p > 0.05). However, significant time effects were observed for phosphorylation of JNK (p < 0.01), HSP27 (p < 0.01), and STAT1 (p = 0.03). Phosphorylation of JNK, HSP27, and STAT1 was significantly elevated from BL at 1H for both HV and HI. CONCLUSIONS: HV and HI lower body resistance exercise protocols appear to elicit similar MAPK activation in resistance-trained men.


Subject(s)
High-Intensity Interval Training/methods , MAP Kinase Signaling System/physiology , Mitogen-Activated Protein Kinase Kinases/metabolism , Muscle, Skeletal/physiology , Physical Conditioning, Human/physiology , Resistance Training/methods , Exercise/physiology , Humans , Leg/physiology , Male , Physical Conditioning, Human/methods , Physical Exertion/physiology , Physical Fitness/physiology , Young Adult
4.
J Strength Cond Res ; 30(3): 626-34, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26418369

ABSTRACT

This study investigated the effects of high-intensity interval training (HIIT) and ß-hydroxy-ß-methylbutyric free acid (HMB) supplementation on physical working capacity at the onset of neuromuscular fatigue threshold (PWC(FT)). Thirty-seven participants (22 men, 15 women; 22.8 ± 3.4 years) completed an incremental cycle ergometer test (graded exercise test [GXT]); electromyographic amplitude from the right vastus lateralis was recorded. Assessments occurred preceding (PRE) and after 4 weeks of supplementation (POST). Participants were randomly assigned to control (C, n = 9), placebo (P, n = 14), or supplementation (S, n = 14) groups. Both P and S completed 12 HIIT sessions, whereas C maintained normal diet and activity patterns. The PWC(FT) (W) was determined using the maximal perpendicular distance (D(MAX)) method. Electromyographic amplitude (µVrms) over time was used to generate a cubic regression. Onset of fatigue (TF) was the x-value of the point on the regression that was at D(MAX) from a line between the first and last data points. The PWC(FT) was estimated using TF and GXT power-output increments. The 2-way analysis of variance (ANOVA) (group × time) resulted in a significant interaction for PWC(FT) (F = 6.69, p = 0.004). Post hoc analysis with 1-way ANOVA resulted in no difference in PWC(FT) among groups at PRE (F = 0.87, p = 0.43); however, a difference in PWC(FT) was shown for POST (F = 5.46, p = 0.009). Post hoc analysis among POST values revealed significant differences between S and both P (p = 0.034) and C (p = 0.003). No differences (p = 0.226) were noted between P and C. Paired samples t-tests detected significant changes after HIIT for S (p < 0.001) and P (p = 0.016), but no change in C (p = 0.473). High-intensity interval training increased PWC(FT), but HMB with HIIT was more effective than HIIT alone. Furthermore, it seems that adding HMB supplementation with HIIT in untrained men and women may further improve endurance performance measures.


Subject(s)
Dietary Supplements , Muscle Fatigue/physiology , Physical Conditioning, Human/methods , Physical Conditioning, Human/physiology , Quadriceps Muscle/physiology , Valerates/administration & dosage , Adult , Double-Blind Method , Electromyography , Exercise Test , Exercise Tolerance , Female , Humans , Male , Muscle Fatigue/drug effects , Physical Exertion/physiology , Young Adult
5.
Muscle Nerve ; 51(1): 132-3, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25186664

ABSTRACT

INTRODUCTION: The aim of this study was to examine the relationship between serum C-terminal agrin fragment (CAF) concentrations and neuromuscular fatigue in older adults. METHODS: Twenty-two healthy older men and women volunteered for this study. Resting fasted blood samples were collected and prepared for measurement of serum CAF concentration by a commercially available ELISA kit. The onset of neuromuscular fatigue was measured by monitoring electromyographic fatigue curves from the vastus lateralis muscle using the physical working capacity at fatigue threshold (PWCFT ) test. RESULTS: A significant inverse correlation for men was observed between CAF and PWCFT (r = -0.602; P = 0.05), but not for women (r = 0.208; P = 0.54). After controlling for age and body mass index, significant correlations (r = -0.69; P = 0.042) remained for men, but not for women (r = 0.12; P = 0.76). CONCLUSIONS: These data suggest that serum CAF concentrations were significantly related to the onset of neuromuscular fatigue independent of age and BMI in men only.


Subject(s)
Agrin/blood , Fatigue/blood , Fatigue/physiopathology , Muscle Fatigue , Aged , Aged, 80 and over , Aging , Agrin/chemistry , Electromyography , Ergometry , Female , Humans , Male , Middle Aged , Muscle, Skeletal/physiopathology
6.
J Sports Sci Med ; 14(2): 452-8, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25983596

ABSTRACT

To evaluate the time course of EMG frequency changes during a three-minute maximal effort cycling test (3MT) session and to examine which parameter between mean (MNF) and median (MDF) frequency is more suitable for evaluation of changes in neuromuscular function throughout a 3MT. Eighteen recreationally-active men volunteered to participate in this study. Maximum voluntary contraction (MVC) was measured using a dynamometer to determine maximal EMG frequency of the vastus lateralis (VL) of the kicking leg during isometric knee extension. A maximal oxygen consumption test (VO2peak) on a cycle ergometer was performed to establish the appropriate load profile for the 3MT which was completed after a period of at least 48 hours. MNF, MDF and power output (PO) values were measured at 10-second epochs throughout the duration of the 3MT. Repeated measures analysis of variance was used to compare the changes in EMG frequency, relative to maximal values from the MVC, and change in PO during the testing procedure. MNF, Root Mean Square (RMS), and PO significantly decreased during the 3MT, while MDF did not change significantly. Statistically, EMG frequency and PO decreased at first and remained constant in response to the 3MT, which may be reflective of differing patterns of muscle fiber type fatigue throughout the testing session. Due to decreased variability, changes in neuromuscular function during this protocol may be better evaluated using MNF than MDF. Key pointsEMG frequency decreased initially and remained constant in response to all-out cycling test.The change in EMG frequency and power output were similar during all-out cycling test.MNF may be better than MDF for neuromuscular function evaluation during all-out cycling test due to decreased variability.

7.
J Strength Cond Res ; 28(7): 1812-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24950225

ABSTRACT

The relationships between 30-m sprint time and performance on a nonmotorized treadmill (TM) test and a vertical jump test were determined in this investigation. Seventy-eight physically active men and women (22.9 ± 2.7 years; 73.0 ± 14.7 kg; 170.7 ± 10.4 cm) performed a 30-second maximal sprint on the curve nonmotorized TM after 1 familiarization trial. Pearson product-moment correlation coefficients produced significant (p ≤ 0.05) moderate to very strong relationships between 30-m sprint time and body mass (r = -0.37), %fat (r = 0.79), peak power (PP) (r = -0.59), relative PP (r = -0.42), time to peak velocity (r = -0.23) and TM sprint times at 10 m (r = 0.48), 20 m (r = 0.59), 30 m (r = 0.67), 40 m (r = 0.71), and 50 m (r = 0.75). Strong relationships between 30-m sprint time and peak (r = -0.479) and mean vertical jump power (r = -0.559) were also observed. Subsequently, stepwise regression was used to produce two 30-m sprint time prediction models from TM performance (TM1: body mass + TM data and TM2: body composition + TM data) in a validation group (n = 39), and then crossvalidated against another group (n = 39). As no significant differences were observed between these groups, data were combined (n = 72) and used to create the final prediction models (TM1: r = 0.75, standard error of the estimate (SEE) = 0.27 seconds; TM2: r = 0.84, SEE = 0.22 seconds). These final movement-specific models seem to be more accurate in predicting 30-m sprint time than derived peak (r = 0.23, SEE = 0.48 seconds) and mean vertical jump power (r = 0.31, SEE = 0.45 seconds) equations. Consequently, sprinting performance on the TM can significantly predict short-distance sprint time. It, therefore, may be used to obtain movement-specific measures of sprinting force, velocity, and power in a controlled environment from a single 30-second maximal sprinting test.


Subject(s)
Athletic Performance/physiology , Exercise Test , Running/physiology , Adiposity , Adult , Body Weight , Exercise Test/instrumentation , Female , Humans , Male , Models, Theoretical , Predictive Value of Tests , Young Adult
8.
J Sports Sci Med ; 13(1): 145-50, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24570618

ABSTRACT

Recently, the Dynavision™ D2 Visuomotor Training Device (D2) has emerged as a tool in the assessment of reaction time (RT); however, information regarding the reliability of the D2 have been limited, and to date, reliability data have been limited to non- generalizable samples. Therefore, the purpose of this study was to establish intraclass correlation coefficients (ICC2,1) for the D2 that are generalizable across a population of recreationally active young adults. Forty-two recreationally active men and women (age: 23.41 ± 4.84 years; height: 1.72 ± 0.11 m; mass: 76.62 ± 18.26 Kg) completed 6 trials for three RT tasks of increasing complexity. Each trial was separated by at least 48-hours. A repeated measures ANOVA was used to detect differences in performance across the six trials. Intraclass correlation coefficients (ICC2,1) standard error of measurement (SEM), and minimal differences (MD) were used to determine the reliability of the D2 from the two sessions with the least significant difference score. Moderate to strong reliability was demonstrated for visual RT (ICC2,1: 0.84, SEM: 0.033), and reactive ability in both Mode A and Mode B tasks (Mode A hits: ICC2,1: 0.75, SEM: 5.44; Mode B hits: ICC2,1: 0.73, SEM: 8.57). Motor RT (ICC2,1: 0.63, SEM: 0.035s) showed fair reliability, while average RT per hit for Modes A and B showed moderate reliability (ICC2,1: 0.68, SEM: 0.43 s and ICC2,1: 0.72, SEM: 0.03 s respectively). It appears that one familiarization trial is necessary for the choice reaction time (CRT) task while three familiarization trials are necessary for reactive RT tasks. In conclusion, results indicate that the Dynavision™ D2 is a reliable device to assess neuromuscular reactivity given that an adequate practice is provided. The data presented are generalizable to a population of recreationally active young adults. Key PointsThe Dynavision™ D2 is a light-training reaction device, developed to train sensory motor integration through the visual system, offering the ability to assess visual and motor reaction to both central and peripheral stimuli, with a capacity to integrate increasing levels of cognitive challenge.The Dynavision™ D2 is a reliable instrument for assessing reaction time in recreationally active young adults.It is recommended that one familiarization trial is necessary for the choice reaction time task assessment to learn the test protocol, while three familiarization trials are needed for reactive ability in Mode A and Mode B before a subsequent reliable baseline score can be established.Significant training effects were observed for all reaction time tests and should be taken into account with continuous trials.

9.
Arch Gerontol Geriatr ; 61(1): 27-32, 2015.
Article in English | MEDLINE | ID: mdl-25957058

ABSTRACT

The purpose of this study was to investigate the effects of short term resistance exercise on neuromuscular fatigue threshold (PWCFT), strength, functional performance, and body composition in older adults. Twenty-three participants (71.2 ± 6.0 yr) were randomly assigned to 6 weeks of resistance exercise (EXE) or control (CONT). A submaximal cycle ergometer test, physical working capacity at fatigue threshold, was used to determine PWCFT. Strength was assessed with predicted leg extension 1-RM and functional performance with time to complete 5 chair rises (CHAIR) and walk an 8-ft course (WALK). PWCFT, 1-RM and CHAIR significantly (p<0.05) improved in the EXE (27%, 24%, 27%) compared with CONT (-0.1%, 7%, 6%), respectively. The results of this study suggest that short term EXE improved strength, functionality and the capacity to delay the onset of neuromuscular fatigue in older adults.


Subject(s)
Aging , Exercise Tolerance/physiology , Fatigue/prevention & control , Muscle, Skeletal/physiopathology , Resistance Training/methods , Walking/physiology , Aged , Body Composition , Electromyography , Exercise Test , Fatigue/physiopathology , Female , Humans , Male
10.
Int J Endocrinol ; 2015: 856708, 2015.
Article in English | MEDLINE | ID: mdl-25792982

ABSTRACT

Objective. To examine the endocrine response to a bout of heavy resistance exercise following acute ß-hydroxy-ß-methylbutyrate free acid (HMB-FA) ingestion. Design. Twenty resistance trained men were randomized and consumed either 1 g of HMB-FA (BetaTor) or placebo (PL) 30 min prior to performing an acute heavy resistance exercise protocol. Blood was obtained before (PRE), immediately after (IP), and 30 min after exercise (30P). Circulating concentrations of testosterone, growth hormone (GH), insulin-like growth factor (IGF-1), and insulin were assayed. Data were analyzed with a repeated measures ANOVA and area under the curve (AUC) was analyzed by the trapezoidal rule. Results. The resistance exercise protocol resulted in significant elevations from PRE in testosterone (P < 0.01), GH (P < 0.01), and insulin (P = 0.05) at IP, with GH (P < 0.01) and insulin (P < 0.01) remaining elevated at 30P. A significant interaction was noted between groups in the plasma GH response at IP, which was significantly higher following HMB-FA compared to PL (P < 0.01). AUC analysis revealed an elevated GH and IGF-1 response in the HMB-FA group compared to PL. Conclusion. HMB-FA prior to resistance exercise augments the GH response to high volume resistance exercise compared to PL. These findings provide further support for the potential anabolic benefits associated with HMB supplementation.

11.
Physiol Rep ; 3(7)2015 Jul.
Article in English | MEDLINE | ID: mdl-26197935

ABSTRACT

Resistance exercise paradigms are often divided into high volume (HV) or high intensity (HI) protocols, however, it is unknown whether these protocols differentially stimulate mTORC1 signaling. The purpose of this study was to examine mTORC1 signaling in conjunction with circulating hormone concentrations following a typical HV and HI lower-body resistance exercise protocol. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Fine needle muscle biopsies were completed at BL, 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HV and HI produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following HI compared to HV (P = 0.01-0.02), whereas the lactate response was significantly higher following HV compared to HI (P = 0.003). The growth hormone, cortisol, and insulin responses were significantly greater following HV compared to HI (P = 0.0001-0.04). No significant differences between protocols were observed for the IGF-1 or testosterone response. Intramuscular anabolic signaling analysis revealed a significantly greater (P = 0.03) phosphorylation of IGF-1 receptor at 1H following HV compared to HI. Phosphorylation status of all other signaling proteins including mTOR, p70S6k, and RPS6 were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following HV and HI, both protocols appeared to elicit similar mTORC1 activation in resistance-trained men.

12.
J Int Soc Sports Nutr ; 11: 16, 2014.
Article in English | MEDLINE | ID: mdl-24782684

ABSTRACT

BACKGROUND: Previous research combining Calcium ß-hydroxy-ß-methylbutyrate (CaHMB) and running high-intensity interval training (HIIT) have shown positive effects on aerobic performance measures. The purpose of this study was to examine the effect of ß-hydroxy-ß-methylbutyric free acid (HMBFA) and cycle ergometry HIIT on maximal oxygen consumption (VO2peak), ventilatory threshold (VT), respiratory compensation point (RCP) and time to exhaustion (Tmax) in college-aged men and women. METHODS: Thirty-four healthy men and women (Age: 22.7 ± 3.1 yrs ; VO2peak: 39.3 ± 5.0 ml · kg(-1) · min(-1)) volunteered to participate in this double-blind, placebo-controlled design study. All participants completed a series of tests prior to and following treatment. A peak oxygen consumption test was performed on a cycle ergometer to assess VO2peak, Tmax, VT, and RCP. Twenty-six participants were randomly assigned into either a placebo (PLA-HIIT) or 3 g per day of HMBFA (BetaTor™) (HMBFA-HIIT) group. Eight participants served as controls (CTL). Participants in the HIIT groups completed 12 HIIT (80-120% maximal workload) exercise sessions consisting of 5-6 bouts of a 2:1 minute cycling work to rest ratio protocol over a four-week period. Body composition was measured with dual energy x-ray absorptiometry (DEXA). Outcomes were assessed by ANCOVA with posttest means adjusted for pretest differences. RESULTS: The HMBFA-HIIT intervention showed significant (p < 0.05) gains in VO2peak, and VT, versus the CTL and PLA-HIIT group. Both PLA-HIIT and HMBFA-HIIT treatment groups demonstrated significant (p < 0.05) improvement over CTL for Tmax, and RCP with no significant difference between the treatment groups. There were no significant differences observed for any measures of body composition. An independent-samples t-test confirmed that there were no significant differences between the training volumes for the PLA-HIIT and HMBFA-HIIT groups. CONCLUSIONS: Our findings support the use of HIIT in combination with HMBFA to improve aerobic fitness in college age men and women. These data suggest that the addition of HMBFA supplementation may result in greater changes in VO2peak and VT than HIIT alone. STUDY REGISTRATION: The study was registered on ClinicalTrials.gov (ID NCT01941368).

13.
Arch Gerontol Geriatr ; 59(2): 300-4, 2014.
Article in English | MEDLINE | ID: mdl-24856645

ABSTRACT

The relationship between PWCFT and common measures used to assess sarcopenia in older adults were examined. Fifty-eight older adults [age: 71.1 ± 6.2 years; body mass index (BMI): 28.0 ± 5.4 kg/m(2)] completed the testing procedures. Sarcopenia-related body composition was measured by dual-energy X-ray absorptiometry and participants performed a discontinuous cycle ergometry test to determine PWCFT. Functionality assessments included maximal isometric grip strength (GRIP) and sit-to-stand (STS) repetitions in 30s. Muscle quality (MQ) was defined as GRIP relative to appendicular lean soft tissue (ALM), while skeletal muscle index (SMI) was defined as ALM/height(2). Pearson correlations were used to examine the relationships among dependent variables. PWCFT showed significant relationships with ALM (r=0.57), SMI (r=0.47), body fat percentage (BF%) (r=-0.50), GRIP (r=0.49), and STS (r=0.44). For follow-up analyses, study participants were categorized into low sarcopenia risk (n=31) or high sarcopenia risk (n=27) groups by SMI. Sarcopenia risk was associated with PWCFT [odds ratio (OR): 1.051, 95% confidence interval (CI): 1.016-1.087] and STS (OR: 1.305, CI: 1.060-1.607), but not GRIP (OR: 1.098, CI: 0.989-1.218). Using receiver-operator characteristic curve analysis, both PWCFT [area under the curve (AUC): 0.737, CI: 0.608-0.866, optimal cutoff: 37.5 W] and STS (AUC: 0.749, CI: 0.623-0.874, optimal cutoff: 12.5 repetitions) showed discriminative ability with regard to sarcopenia risk. The current data suggest that the neuromuscular fatigue threshold, as measured by PWCFT, is related to measures of body composition and function in older adults.


Subject(s)
Body Composition , Muscle Fatigue/physiology , Muscle Strength/physiology , Muscle, Skeletal/physiopathology , Sarcopenia/physiopathology , Absorptiometry, Photon , Aged , Aged, 80 and over , Body Mass Index , Electromyography , Exercise Test , Female , Hand Strength/physiology , Humans , Male , Middle Aged , Risk
14.
Nutr Res ; 33(6): 464-72, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23746562

ABSTRACT

Phosphatidylserine (PS) may attenuate the adverse effects of physical fatigue. Therefore, we investigated the effects of a multi-ingredient supplement containing 400 mg/d PS and 100 mg/d caffeine (supplement [SUP]) for 2 weeks on measures of cognitive function (CF), reaction time (RT), and mood (MD) following an acute exercise stress. It is hypothesized that PS will maintain preexercise CF and RT scores, while attenuating postexercise fatigue. Participants completed 2 acute bouts of resistance exercise (T1 and T2) separated by 2-week ingestion of SUP or control (CON). Outcome measures were assessed pre- and postexercise. When collapsed across groups, a significant decrease in RT performance was seen in the 60-second reaction drill from pre- to postexercise at T1. All other RT tests were similar from pre- to postexercise at T1. Reaction time was not significantly changed by PS. When collapsed across groups, a significant increase in performance of the serial subtraction test was seen. A significant increase (8.9% and 7.1%) in the number of correct answers and a significant decrease (8.0% and 7.5%) in time to answer were seen from pre- to postworkout at T1 and T2, respectively. A significant increase in total MD score from pre- to postworkout was observed for CON but not for PS at T2. Phosphatidylserine significantly attenuated pre- to postexercise perception of fatigue compared to CON. Ingestion of SUP for 14 days appears to attenuate postexercise MD scores and perception of fatigue, but does not affect CF or RT, in recreationally trained individuals.


Subject(s)
Affect/drug effects , Caffeine/administration & dosage , Dietary Supplements , Exercise/physiology , Fatigue/drug therapy , Phosphatidylserines/administration & dosage , Adult , Anthropometry , Double-Blind Method , Female , Humans , Male , Perception , Surveys and Questionnaires , Young Adult
15.
Exp Gerontol ; 48(9): 933-9, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23832078

ABSTRACT

This study examined the effects of an oral nutritional supplement fortified with two different doses of beta-alanine on body composition, muscle function and physical capacity in older adults. Using a double-blind placebo controlled design, 60 men and women (age ± SD = 70.7 ± 6.2 yrs) were randomly assigned to one of three treatment groups: 1) oral nutritional supplement (ONS; n = 20) (8 oz; 230 kcal; 12 g PRO; 31 g CHO; 6 g FAT), 2) ONS plus 800 mg beta-alanine (ONS800; n = 19), and 3) ONS plus 1200 mg beta-alanine (ONS1200; n = 21). Treatments were consumed twice per day for 12 weeks. At pre- and post-supplementation period, participants performed a discontinuous, submaximal cycle ergometry test to determine physical working capacity at fatigue threshold (PWCFT). Fat mass, total body and arm lean soft tissue mass (ALSTM) were measured with DEXA while muscle strength was assessed with handgrip dynamometry (GRIP) and 30-s sit-to-stand (STS) was used to measure lower body functionality. Muscle quality (MQ) was calculated with GRIPmax and DEXA derived ALSTM [GRIP (kg)·ALSTM (kg)(-1)]. Two-way analysis of variance was used to compare pre- to post-supplementation measures and group differences. There were 16 dropouts over the duration of the study. Final group sizes were ONS = 16 (m = 11, w = 5), ONS800 = 15 (m = 5, w = 10), and ONS1200 = 13 (m = 6, w = 7). No significant changes were observed for body composition or GRIP values pre to post. Significant increases in PW(CFT) were seen in ONS1200 (13.6%) and ONS800 (17.8%) pre- to post-supplementation (p < 0.05). These changes were significantly greater (p < 0.05) than the changes in ONS (-6.3%). ONS1200 and ONS had significant increases in STS (22.2 and 10.7%, respectively). While ONS significantly increased in STS, no differences (p > 0.05) in change scores were found between ONS and ONS800. ONS fortified with beta-alanine may improve physical working capacity, muscle quality and function in older men and women. These findings could have importance in the perception of frailty, and the maintenance of health and independent living in older adults.


Subject(s)
Dietary Supplements , Physical Endurance/drug effects , beta-Alanine/administration & dosage , Administration, Oral , Aged , Body Composition/drug effects , Dietary Proteins/administration & dosage , Dose-Response Relationship, Drug , Double-Blind Method , Energy Intake , Exercise Test/methods , Female , Hand Strength/physiology , Humans , Male , Middle Aged , Muscle Strength/drug effects , Muscle Strength/physiology , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiopathology , Physical Endurance/physiology , beta-Alanine/pharmacology
16.
J Appl Physiol (1985) ; 115(8): 1173-82, 2013 Oct 15.
Article in English | MEDLINE | ID: mdl-23908318

ABSTRACT

The purpose of this study was to examine the effect of ß-hydroxy-ß-methylbutyrate-free acid (HMB-FA) and cold-water immersion (CWI) on circulating concentrations of TNF-α and monocyte TNF-α receptor 1 (TNFR1) expression. Forty resistance-trained men (22.3 ± 2.4 yr) were randomized into four groups [placebo (PL), HMB-FA, CWI, and HMB-FA-CWI] and performed an acute, intense exercise protocol (four sets of up to 10 repetitions of the squat, dead lift, and split squat). Participants also performed four sets of up to 10 repetitions of the squat at 24 and 48 h following the initial exercise bout. Blood was sampled before exercise (PRE), immediately postexercise (IP), and 30 min, 24 h, and 48 h postexercise (30P, 24P, and 48P, respectively). Circulating TNF-α was assayed, and TNFR1 expression on CD14+ monocytes was measured by flow cytometry. The exercise protocol significantly elevated TNF-α in only PL (P = 0.006) and CWI (P = 0.045) IP. Mean percent changes show that TNF-α significantly increased from PRE to IP for only PL and CWI groups (P < 0.05), whereas the percent change of TNF-α for HMB-FA and HMB-FA-CWI was not significant. TNFR1 expression was elevated in PL (P = 0.023) and CWI (P = 0.02) at 30P compared with PRE, whereas both HMB-FA-treated groups did not increase significantly. In conclusion, HMB-FA attenuated circulating TNF-α IP and TNFR1 expression during recovery compared with PL and CWI. HMB-FA supplementation may attenuate the initial immune response to intense exercise, which may reduce recovery time following intense exercise.


Subject(s)
Dietary Supplements , Inflammation Mediators/blood , Monocytes/drug effects , Muscle Contraction , Muscle, Skeletal/drug effects , Receptors, Tumor Necrosis Factor, Type I/blood , Resistance Training , Tumor Necrosis Factor-alpha/blood , Valerates/administration & dosage , Adult , Biomarkers/blood , Cold Temperature , Double-Blind Method , Down-Regulation , Humans , Immersion , Lipopolysaccharide Receptors/blood , Male , Monocytes/immunology , Monocytes/metabolism , Muscle, Skeletal/immunology , Muscle, Skeletal/metabolism , Recovery of Function , Time Factors , Water , Young Adult
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