Carbohydrate Mouth Rinsing Does Not Prevent the Decline in Maximal Strength After Fatiguing Exercise

Purpose:To determine whether repeated carbohydrate (CHO) mouth rinsing would improve neuromuscular performance during high-intensity fatiguing contractions.Methods:Eighteen young men (age 26.1 ± 5.0 y, BMI 22.9 ± 1.9) performed 3 maximal voluntary isometric contractions (MVICPRE). Immediately after, they completed 10-second mouth rinse with 6.4% maltodextrin solution (MAL), 7.1% glucose solution (GLU), water (W), artificially sweetened solution (PLA), or a control trial with no rinse (CON) in a crossover protocol. Subjects performed 5 sets of 30 isokinetic fatiguing contractions at 180°/s, and an MVICPOST with their elbow flexors was performed after each mouth rinse. Mechanical and electromyographic (EMG) signals were recorded from the biceps brachii and parameters of interest analyzed.Results:When rinsing the mouth with a solution containing CHO, independently of the sweetness, isokinetic performance was enhanced as shown by the greater total work achieved in comparison with CON. The decay of torque and mean fiber-conduction velocity (MFCV) recorded at the end of the fatiguing task was lower when rinsing the mouth with GLU than with CON. The torque recorded during the MVICPOST was greater with CHO with respect to CON, and this was associated to a lower decay of MFCV.Conclusions:CHO mouth rinse counteracts fatigue-induced decline in neuromuscular performance, supporting the notion that CHO rinse may activate positive afferent signals able to modify motor output. Repeated mouth rinsing with sweet and nonsweet CHO-containing solutions can improve neuromuscular performance during an isokinetic intermittent fatiguing task.

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Carbohydrate Mouth Rinsing Does Not Enhance Maximal Strength or Motor-Unit Recruitment Following Fatigue

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000485204.22055.3a ◽

2016 ◽

Vol 48 ◽

pp. 65

Author(s):

Marcin K. Szczyglowski ◽

Joshua D. Wren ◽

Daniel J. Schubert ◽

Christopher D. Black

Keyword(s):

Motor Unit ◽

Motor Unit Recruitment ◽

Maximal Strength ◽

Mouth Rinsing

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Cognitive task during fatiguing exercise increases the sensory-motor performance in professional dancers

Gazzetta Medica Italiana Archivio per le Scienze Mediche ◽

10.23736/s0393-3660.18.03801-9 ◽

2019 ◽

Vol 178 (5) ◽

Author(s):

Ömer Pamuk ◽

Mehmet A. Özçelik ◽

Neşe Toktaş ◽

Aliye Gündoğdu ◽

İ. Ethem Hindistan ◽

...

Keyword(s):

Motor Performance ◽

Cognitive Task ◽

Sensory Motor ◽

Fatiguing Exercise ◽

Professional Dancers

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Changes in Maximal Strength and Home Run Performance in NCAA Division I Baseball Players Across 3 Competitive Seasons: A Descriptive Study

Journal of Functional Morphology and Kinesiology ◽

10.3390/jfmk6010004 ◽

2021 ◽

Vol 6 (1) ◽

pp. 4

Author(s):

W. Guy Hornsby ◽

Abigail L. Tice ◽

Jason D. Stone ◽

Justin J. Merrigan ◽

Joshua Hagen ◽

...

Keyword(s):

Ncaa Division I ◽

Repeated Measures ◽

National Collegiate Athletic Association ◽

Descriptive Study ◽

Peak Force ◽

Division I ◽

Maximal Strength ◽

Baseball Players ◽

Repeated Measures Analysis ◽

Division 1

The purpose of this longitudinal, descriptive study was to observe changes in maximal strength measured via isometric clean grip mid-thigh pull and home runs (total and home runs per game) across three years of training and three competitive seasons for four National Collegiate Athletic Association (NCAA) Division 1 baseball players. A one-way repeated measures analysis of variance (ANOVA) was performed, revealing significant univariate effects of time for peak force (PF) (p = 0.003) and peak force allometrically scaled (PFa) (p = 0.002). Increases in PF were noted from season 1 to season 2 (p = 0.031) and season 3 (p = 0.004), but season 2 was not significantly different than season 3 (p = 0.232). Additionally, increases in PFa were noted from season 1 to season 2 (p = 0.010) and season 3 (p < 0.001), but season 2 was not significantly different than season 3 (p = 0.052). Home runs per game rose from the 2009 (0.32) to 2010 season (1.35) and dropped during the 2011 season (1.07). A unique aspect of the study involves 2010 being the season in which ball-bat coefficient of restitution (BBCOR) bats were introduced to the NCAA competition.

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“Going Backward”: Effects of age and fatigue on posterior-directed falls in Parkinson disease

Neurorehabilitation ◽

10.3233/nre-210040 ◽

2021 ◽

pp. 1-9

Author(s):

Evan V. Papa ◽

Rita M. Patterson ◽

Nicoleta Bugnariu

Keyword(s):

Postural Control ◽

Parkinson Disease ◽

Repeated Measures ◽

Center Of Pressure ◽

Angular Displacement ◽

Reaction Times ◽

Older Individuals ◽

Peak Knee ◽

Significant Difference ◽

Fatiguing Exercise

BACKGROUND: Nearly half of persons with Parkinson disease (PD) report fatigue as a factor in their fall history. However, it is unknown whether these self-reported falls are caused by a sensation of fatigue or performance fatigue. OBJECTIVE: We sought to investigate the influences of performance fatigue and age on postural control in persons with PD. METHODS: Individuals with PD (n = 14) underwent postural control assessments before (T0) and immediately after (T1) fatiguing exercise. Biomechanical data were gathered on participants completing a treadmill-induced, posterior-directed fall. Performance fatigue was produced using lower extremity resistance exercise on an isokinetic ergometer. Repeated measures ANCOVAs were used with age as a covariate to determine the effects of performance fatigue on biomechanical variables. RESULTS: After adjustment for age, there was a statistically significant difference in peak center of pressure (COP) latency during the support phase of recovery. Pairwise comparisons demonstrated a decrease in peak ankle displacement from T0 to T1. Age was also found to be significantly related to reaction time and peak knee displacement while participants were fatigued. CONCLUSIONS: The decreased peak COP latency, along with decreased ankle angular displacement, suggest that persons with PD adopt a stiffening strategy in response to backward directed falls. Postural stiffening is not uncommon in persons with PD and could be a risk factor for falls. Older individuals with PD demonstrate slower mobility scores and decreased reaction times in the setting of fatigue, suggesting a combined effect of the aging and fatigue processes.

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Maximal strength training improves work economy, rate of force development and maximal strength more than conventional strength training

European Journal of Applied Physiology ◽

10.1007/s00421-013-2586-y ◽

2013 ◽

Vol 113 (6) ◽

pp. 1565-1573 ◽

Cited By ~ 30

Author(s):

Jørn Heggelund ◽

Marius S. Fimland ◽

Jan Helgerud ◽

Jan Hoff

Keyword(s):

Strength Training ◽

Rate Of Force Development ◽

Maximal Strength ◽

Force Development ◽

Work Economy

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Effects of Two Months of Very Low Carbohydrate Ketogenic Diet on Body Composition, Muscle Strength, Muscle Area, and Blood Parameters in Competitive Natural Body Builders

Nutrients ◽

10.3390/nu13020374 ◽

2021 ◽

Vol 13 (2) ◽

pp. 374

Author(s):

Antonio Paoli ◽

Lorenzo Cenci ◽

PierLuigi Pompei ◽

Nese Sahin ◽

Antonino Bianco ◽

...

Keyword(s):

Body Composition ◽

Muscle Strength ◽

Ketogenic Diet ◽

Inflammatory Cytokines ◽

Blood Parameters ◽

Maximal Strength ◽

Muscle Area ◽

Low Carbohydrate ◽

Before And After ◽

Adequate Quantity

Background: Ketogenic diet (KD) is a nutritional approach that restricts daily carbohydrates, replacing most of the reduced energy with fat, while maintaining an adequate quantity of protein. Despite the widespread use of KD in weight loss in athletes, there are still many concerns about its use in sports requiring muscle mass accrual. Thus, the present study sought to investigate the influence of a KD in competitive natural body builders. Methods: Nineteen volunteers (27.4 ± 10.5 years) were randomly assigned to ketogenic diet (KD) or to a western diet (WD). Body composition, muscle strength and basal metabolic rate were measured before and after two months of intervention. Standard blood biochemistry, testosterone, IGF-1, brain-derived neurotrophic factor (BDNF) and inflammatory cytokines (IL6, IL1β, TNFα) were also measured. Results: Body fat significantly decreased in KD (p = 0.030); whilst lean mass increased significantly only in WD (p < 0.001). Maximal strength increased similarly in both groups. KD showed a significant decrease of blood triglycerides (p < 0.001), glucose (p = 0.001), insulin (p < 0.001) and inflammatory cytokines compared to WD whilst BDNF increased in both groups with significant greater changes in KD (p < 0.001). Conclusions: KD may be used during body building preparation for health and leaning purposes but with the caution that hypertrophic muscle response could be blunted.

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Early Maximal Strength Training Improves Leg Strength and Postural Stability in Elderly Following Hip Fracture Surgery

Geriatric Orthopaedic Surgery & Rehabilitation ◽

10.1177/21514593211015103 ◽

2021 ◽

Vol 12 ◽

pp. 215145932110151

Author(s):

Ole Kristian Berg ◽

Jens-Meinhard Stutzer ◽

Jan Hoff ◽

Eivind Wang

Keyword(s):

Hip Fracture ◽

Muscle Strength ◽

Strength Training ◽

Postural Stability ◽

Maximal Strength ◽

Leg Press ◽

Hip Fracture Surgery ◽

Downward Spiral ◽

Conventional Physiotherapy ◽

Fracture Surgery

Introduction: Hip fractures predominantly occur in the geriatric population and results in increased physical inactivity and reduced independency, largely influenced by a downward spiral of ambulatory capacity, related to loss of skeletal muscle strength and postural stability. Thus, effective postoperative treatment, targeting improvements in muscle strength, is sought after. Materials & Methods: Twenty-one hip fracture patients (>65 yr) were randomized to 8 weeks of either conventional physiotherapy control group (CG), or leg press and hip abduction maximal strength training (MST) 3 times per week. MST was performed applying heavy loads (85-90% of 1 repetition maximum; 1RM) and 4-5 repetitions in 4 sets. Maximal strength (bi- and unilateral 1RM), postural stability (unipedal stance test; UPS), and DEXA-scan bone mineral content/ density (BMC/BMD) were measured before and after the 8-week rehabilitation. Results: Both MST and conventional physiotherapy improved bilateral leg press 1RM by 41 ± 27 kg and 29 ± 17 kg, respectively (both p < 0.01), while unilateral leg press 1RM only increased after MST (within group and between groups difference: both p < 0.05). MST also resulted in an increase in abduction 1RM in both the fractured (5 kg, 95%CI: 2-7; p < 0.01) and healthy limb (6 kg, 95%CI: 3-9; p < 0.01), while no such improvement was apparent in the CG (between groups difference: p < 0.01). Finally, MST improved UPS of the fractured limb (p < 0.05). No differences were observed in BMC or BMD following the 8 weeks. Discussion: Early postoperative MST improved lower extremities maximal muscle strength more than conventional physiotherapy and was accompanied by improvements in postural stability. Conclusion: Implementing MST in early rehabilitation after hip fracture surgery should be considered as a relevant treatment to curtail the downward spiral of reduced ambulatory capacity typical for this patient group, possibly reducing the risk of recuring falls and excess mortality. Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03030092

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