scholarly journals Effects of a Ketogenic Diet on Muscle Fatigue in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 955 ◽  
Author(s):  
Anna Sjödin ◽  
Fredrik Hellström ◽  
EwaCarin Sehlstedt ◽  
Michael Svensson ◽  
Jonas Burén
Keyword(s):  
Muscle Fatigue ◽  
Mixed Models ◽  
Perceived Exertion ◽  
Daily Life ◽  
Control Diet ◽  
Normal Weight ◽  
Ratings Of Perceived Exertion ◽  
Daily Life Activities ◽  
Low Carbohydrate ◽  
Handgrip Test

Ketogenic low-carbohydrate high-fat (LCHF) diets are increasingly popular in broad sections of the population. The main objective of this study was to evaluate the effects of a non-energy-restricted ketogenic LCHF diet on muscle fatigue in healthy, young, and normal-weight women. Twenty-four women were randomly allocated to a 4-week ketogenic LCHF diet followed by a 4-week control diet (a National Food Agency recommended diet), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and were included in the analyses. Treatment effects were evaluated using mixed models. The ketogenic LCHF diet had no effect on grip strength or time to fatigue, measured with handgrip test (day 24–26). However, cycling time to fatigue decreased with almost two minutes (−1.85 min 95% CI:[−2.30;−1.40]; p < 0.001) during incremental cycling (day 25–27), accommodated with higher ratings of perceived exertion using the Borg scale (p < 0.01). Participants’ own diary notes revealed experiences of muscle fatigue during daily life activities, as well as during exercise. We conclude that in young and healthy women, a ketogenic LCHF diet has an unfavorable effect on muscle fatigue and might affect perceived exertion during daily life activities.

Effects of handle height and load on the endurance time for simulated demolition tasks

Work ◽  
2021 ◽  
pp. 1-10
Author(s):  
Kai Way Li ◽  
Wenbao Li ◽  
Lu Peng
Keyword(s):  
Muscle Fatigue ◽  
Regression Models ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Endurance Time ◽  
Factors Affecting ◽  
The Mean ◽  
Forceful Exertion ◽  
Load Conditions ◽  
Do So

BACKGROUND: Manual demolition tasks are heavy physical demanding tasks which involve forceful exertion of sustained pushing. They result in muscle fatigue which could lead to musculoskeletal disorders. Assessments of maximum endurance time (MET) are essential in understanding the developing of muscle fatigue for these tasks. OBJECTIVE: The objectives of this study were to determine the effects of handle height and load conditions on the MET, and to establish MET models for the simulated demolition tasks. METHODS: Twenty three male participants performed simulated demolition tasks under three loads and three handle heights conditions until they could not do so any longer. Their METs and ratings of perceived exertion were recorded and analyzed. RESULTS: The results showed that both load and handle height were significant (p <  0.0001) factors affecting the MET. Regression models to predict the MET under handle height and load conditions were established. The mean absolute deviations of these models were between 1.91 and 4.84 min. CONCLUSION: The MET models established may be used to estimate the MET which may be adopted in work/rest arrangement for demolition tasks using a handheld demolition hammer.

The perceptual, heart rate and technical-tactical characteristics of 3 × 3 basketball

2020 ◽  
Vol 15 (5-6) ◽  
pp. 772-782
Author(s):  
Riley B McGown ◽  
Nick B Ball ◽  
Jan S Legg ◽  
Jocelyn K Mara
Keyword(s):  
Heart Rate ◽  
Mixed Models ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Peak Heart Rate ◽  
Basketball Players ◽  
Preparation Programs ◽  
Dependent Variables ◽  
Physical Preparation ◽  
Pool Game

The aim of this study was to investigate the perceptual, heart rate and technical-tactical characteristics of elite male and female 3 × 3 basketball games. Eleven male and twenty-two female elite basketball players were monitored using heart rate telemetry, Ratings of Perceived Exertion (RPE) and video analysis across three 3 × 3 basketball tournaments. Linear mixed models were performed to determine the influence of round (pool game, quarter-final, semi-final, final, classification game) and sex on all dependent variables (alpha = 0.05). There was no difference between sexes for heart rate variables (p = 0.53 - 0.85). The greatest percentage (56.9 ± 20.1%) of game time was spent in heart rate zone 5 (90-100% peak heart rate). Overall RPE was higher in semi-finals (7.2 ± 1.5, p ≤ 0.001, ES: 1.27) and finals (7.7 ± 1.6 p ≤ 0.001, ES: 1.67) compared to pool games (5.1 ± 1.5). An analysis of the technical-tactical actions revealed that there were less steals in semi-finals (p = 0.01, ES = 0.56) and finals (p = 0.01, ES = 0.71) compared to pool games, with no sex-related differences present (p = 0.06 - 0.97). Players generally spent one minute on the bench for every three minutes on the court, creating a 3:1 work to rest ratio. Physical preparation programs for elite 3 × 3 basketball athletes should include exposure to high-intensity activity in which heart rates ≥80% of peak heart rate are reached for periods of time similar to that experienced during gameplay. A 3:1 work-to-rest ratio may be beneficial during conditioning training for this population.

Stationary Exercise in Overweight and Normal Weight Children

2019 ◽  
Vol 31 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Mostafa Yaghoubi ◽  
Philip W. Fink ◽  
Wyatt H. Page ◽  
Sarah P. Shultz
Keyword(s):  
Lower Extremity ◽  
Range Of Motion ◽  
Body Fat ◽  
Muscle Activation ◽  
Perceived Exertion ◽  
Vastus Lateralis ◽  
Normal Weight ◽  
Body Fat Percentage ◽  
Fat Percentage ◽  
Ratings Of Perceived Exertion

Purpose:This study examined differences in lower extremity kinematics and muscle activation patterns between normal weight (NW) and overweight (OW) children during stationary exercises (running in place, frontal kick, and butt kick) at submaximal intensity.Methods:Healthy children (aged 10–13 y) were stratified into OW (n = 10; body fat percentage: 34.97 [8.60]) and NW (n = 15; body fat percentage: 18.33 [4.87]). Electromyography was recorded for rectus femoris, vastus lateralis, biceps femoris, gastrocnemius, and tibialis anterior. In addition, the ratings of perceived exertion and range of motion of hip, knee, and ankle joints were collected during stationary exercises. Repeated-measures analysis of variance compared muscle activation, range of motion, and ratings of perceived exertion between groups and exercises. Friedman test examined sequencing of muscles recruitment.Results:Compared with NW, OW experienced significantly greater ratings of perceived exertion (13.7 [0.8] vs 11.7 [0.7];P < .001) and electromyography amplitude in all muscles apart from vastus lateralis during stationary exercises. In addition, NW children used more consistent muscles’ recruitment pattern in comparison with OW children. The range of motion was similar between groups at all joints.Conclusion:OW children may adopt a more active neuromuscular strategy to provide greater stability and propulsion during stationary exercises. Stationary exercise can be prescribed to strengthen lower extremity muscles in OW children, but mode and intensity must be considered.

scholarly journals A Ketogenic Low-Carbohydrate High-Fat Diet Increases LDL Cholesterol in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 814
Author(s):  
Jonas Burén ◽  
Madelene Ericsson ◽  
Nágila Raquel Teixeira Damasceno ◽  
Anna Sjödin
Keyword(s):  
Ldl Cholesterol ◽  
Control Diet ◽  
Density Lipoprotein ◽  
Normal Weight ◽  
Crossover Design ◽  
High Fat ◽  
Feeding Trial ◽  
Blood Lipid Profile ◽  
Randomized Controlled ◽  
Low Carbohydrate

Ketogenic low-carbohydrate high-fat (LCHF) diets are popular among young, healthy, normal-weight individuals for various reasons. We aimed to investigate the effect of a ketogenic LCHF diet on low-density lipoprotein (LDL) cholesterol (primary outcome), LDL cholesterol subfractions and conventional cardiovascular risk factors in the blood of healthy, young, and normal-weight women. The study was a randomized, controlled, feeding trial with crossover design. Twenty-four women were assigned to a 4 week ketogenic LCHF diet (4% carbohydrates; 77% fat; 19% protein) followed by a 4 week National Food Agency recommended control diet (44% carbohydrates; 33% fat; 19% protein), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and treatment effects were evaluated using mixed models. The LCHF diet increased LDL cholesterol in every woman with a treatment effect of 1.82 mM (p < 0.001). In addition, Apolipoprotein B-100 (ApoB), small, dense LDL cholesterol as well as large, buoyant LDL cholesterol increased (p < 0.001, p < 0.01, and p < 0.001, respectively). The data suggest that feeding healthy, young, normal-weight women a ketogenic LCHF diet induces a deleterious blood lipid profile. The elevated LDL cholesterol should be a cause for concern in young, healthy, normal-weight women following this kind of LCHF diet.

Sodium Bicarbonate Supplementation Does Not Improve Running Anaerobic Sprint Test Performance in Semiprofessional Adolescent Soccer Players

2020 ◽  
Vol 30 (5) ◽  
pp. 330-337
Author(s):  
Rodrigo dos Santos Guimarães ◽  
Alcides Correa de Morais Junior ◽  
Raquel Machado Schincaglia ◽  
Bryan Saunders ◽  
Gustavo Duarte Pimentel ◽  
...  
Keyword(s):  
Sodium Bicarbonate ◽  
Muscle Fatigue ◽  
Perceived Exertion ◽  
Sprint Performance ◽  
Soccer Players ◽  
Fatigue Index ◽  
Countermovement Jump ◽  
Ratings Of Perceived Exertion ◽  
Double Blind ◽  
Repeated Sprint

Ergogenic strategies have been studied to alleviate muscle fatigue and improve sports performance. Sodium bicarbonate (NaHCO3) has improved repeated sprint performance in adult team-sports players, but the effect for adolescents is unknown. The aim of the present study was to evaluate the effect of NaHCO3 supplementation on repeated sprint performance in semiprofessional adolescent soccer players. In a double-blind, placebo-controlled, crossover trial, 15 male semiprofessional adolescent soccer players (15 ± 1 years; body fat 10.7 ± 1.3%) ingested NaHCO3 or a placebo (sodium chloride) 90 min before performing the running anaerobic sprint test (RAST). A countermovement jump was performed before and after the RAST, and ratings of perceived exertion, blood parameters (potential hydrogen and bicarbonate concentration), and fatigue index were also evaluated. Supplementation with NaHCO3 promoted alkalosis, as demonstrated by the increase from the baseline to preexercise, compared with the placebo (potential hydrogen: +0.07 ± 0.01 vs. −0.00 ± 0.01, p < .001 and bicarbonate: +3.44 ± 0.38 vs. −1.45 ± 0.31 mmol/L, p < .001); however, this change did not translate into an improvement in RAST total time (32.12 ± 0.30 vs. 33.31 ± 0.41 s, p = .553); fatigue index (5.44 ± 0.64 vs. 6.28 ± 0.64 W/s, p = .263); ratings of perceived exertion (7.60 ± 0.33 vs. 7.80 ± 0.10 units, p = .525); countermovement jump pre-RAST (32.21 ± 3.35 vs. 32.05 ± 3.51 cm, p = .383); or countermovement jump post-RAST (31.70 ± 0.78 vs. 32.74 ± 1.11 cm, p = .696). Acute NaHCO3 supplementation did not reduce muscle fatigue or improve RAST performance in semiprofessional adolescent soccer players. More work assessing supplementation in this age group is required to increase understanding in the area.

Mobile phone apps’ support for people with mild dementia: A systematic review (Preprint)

2019 ◽  
Author(s):  
Leona Cilar ◽  
Lucija Gosak ◽  
Amanda Briggs ◽  
Klavdija Čuček Trifkovič ◽  
Tracy McClelland ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Thematic Analysis ◽  
Daily Life ◽  
General Term ◽  
Cognitive Domain ◽  
Mild Dementia ◽  
Daily Life Activities ◽  
Human Needs ◽  
People With Dementia ◽  
System Usability Scale

BACKGROUND Dementia is a general term for various disorders characterized by memory impairment and loss of at least one cognitive domain. People with dementia are faced with different difficulties in their daily life activities (DLA). With the use of modern technologies, such as mobile phone apps – often called health apps, their difficulties can be alleviated. OBJECTIVE The aim of this paper was to systematically search, analyze and synthetize mobile phone apps designed to support people with mild dementia in daily life activities in two apps bases: Apple App Store and Google Play Store. METHODS A search was conducted in May 2019 following PRISMA recommendations. Results were analyzed and displayed as tables and graphs. Results were synthetized using thematic analysis which was conducted from 14 components, based on human needs for categorized nursing activities. Mobile phone apps were assessed for quality using the System Usability Scale. RESULTS A total of 15 mobile phone apps were identified applying inclusion and exclusion criteria. Five major themes were identified with thematic analysis: multi-component DLA, communication and feelings, recreation, eating and drinking, and movement. Most of the apps (73%) of the apps were not mentioned in scientific literature. CONCLUSIONS There are many mobile phone apps available in mobile phone markets for the support for people with mild dementia; yet only a few of them are focused on challenges in daily life activities. Most of the available apps were not evaluated nor assessed for quality.

Effect of exercise modality on ratings of perceived exertion at various lactate concentrations

1991 ◽  
Vol 23 (1) ◽  
pp. 88???92 ◽  
Author(s):  
R. K. HETZLER ◽  
R. L. SEIP ◽  
S. H. BOUTCHER ◽  
E. PIERCE ◽  
D. SNEAD ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Exercise Modality

Psychophysical and physiological comparison of squat and semi-squat lifting by young males

1999 ◽  
Vol 2 (1) ◽  
pp. 17-26
Author(s):  
Leon Straker ◽  
Carol Cain
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Lower Heart Rate ◽  
Young Males ◽  
Squat Lifting

A comparison between semi-squat and squat techniques was made for floor to knuckle height lifting using maximum acceptable weight (MAW), ratings of perceived exertion (RPE) and heart rate. Semi-squat lifting resulted in greater MAW with lower RPE and lower heart rate compared to squat lifting. Discomfort was most commonly reported in knees/quadriceps with squat lifting. Twelve of the 13 subjects preferred the semi-squat technique. The results provide evidence that the semi-squat technique may have benefits over the squat technique for lifting a medium sized box from floor to knuckle height.

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