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Effect of quantity and quality of pre-exercise carbohydrate meals on central fatigue.
Khong, TK, Selvanayagam, VS, Hamzah, SH, Yusof, A
Journal of applied physiology (Bethesda, Md. : 1985). 2018;(4):1021-1029
Abstract
Both the quantity and quality of pre-exercise carbohydrate (CHO) meals have been shown to improve endurance performance. However, their role in attenuating central fatigue (CF) is inconclusive. The use of neurophysiological techniques, such as voluntary activation (VA) and the central activation ratio (CAR), alongside maximum voluntary contraction (MVC) and sustained MVC (sMVC) can provide information on CF. Hence, the objective of this study was to investigate the effects of isocaloric pre-exercise meals: 1) a high versus low quantity of CHO and 2) a high quantity of CHO with a high versus low glycemic index (GI) on MVC, VA, and CAR following a 90-min run. The high and low quantity of CHO was 1.5 and 0.8 g/kg body wt, respectively, and high and low GI was ~75 and ~40, respectively. Blood insulin, serotonin, tryptophan, and gaseous exchange were also measured. High CHO preserved sMVC, VA, CAR, and serotonin postrunning with greater CHO oxidation and insulin response, whereas in low CHO, greater reductions in sMVC, VA, and CAR were accompanied by higher serotonin and fat oxidation with lower insulin response. These observations indicate central involvements. Meanwhile, high GI CHO better preserved force (sMVC), CAR, and tryptophan with greater CHO oxidation and insulin response compared with low GI. The findings of this study suggest that pre-exercise meals with varying quantity and quality of CHO can have an effect on CF, where greater CHO oxidation and insulin response found in both high CHO and high GI lead to attenuation of CF. NEW & NOTEWORTHY This paper examined the effects of carbohydrate interventions (high and low: quantity and quality wise) on central activity during prolonged exercise using mainly neurophysiological techniques along with gaseous exchange and blood insulin, serotonin, and tryptophan data.
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Investigation of 2 Types of Self-administered Acupressure for Persistent Cancer-Related Fatigue in Breast Cancer Survivors: A Randomized Clinical Trial.
Zick, SM, Sen, A, Wyatt, GK, Murphy, SL, Arnedt, JT, Harris, RE
JAMA oncology. 2016;(11):1470-1476
Abstract
IMPORTANCE Fatigue is a common and debilitating late-term effect of breast cancer that is associated with poor sleep and decreased quality of life, yet therapies remain limited. Acupressure has reduced fatigue in previous small studies, but rigorous clinical trials are needed. OBJECTIVES To investigate if 6 weeks of 2 types of self-administered acupressure improved fatigue, sleep, and quality of life vs usual care in breast cancer survivors and to determine if changes were sustained during a 4-week washout period. DESIGN, SETTING, AND PARTICIPANTS Phase 3 randomized, single-blind, clinical trial conducted from March 1, 2011, through October 31, 2014. Women were recruited from the Michigan Tumor Registry. INTERVENTIONS Randomization (1:1:1) to 6 weeks of daily self-administered relaxing acupressure, stimulating acupressure, or usual care. MAIN OUTCOMES AND MEASURES The primary outcome was change in the Brief Fatigue Inventory score from baseline to weeks 6 and 10. Secondary analyses were sleep (Pittsburgh Sleep Quality Index) and quality of life (Long-Term Quality of Life Instrument). RESULTS A total of 424 survivors of stages 0 to III breast cancer who had completed cancer treatments at least 12 months previously were screened, and 288 were randomized, with 270 receiving relaxing acupressure (n = 94), stimulating acupressure (n = 90), or usual care (n = 86). One woman withdrew owing to bruising at the acupoints. At week 6, the percentages of participants who achieved normal fatigue levels (Brief Fatigue Inventory score <4) were 66.2% (49 of 74) in relaxing acupressure, 60.9% (42 of 70) in stimulating acupressure, and 31.3% (26 of 84) in usual care. At week 10, a total of 56.3% (40 of 71) in relaxing acupressure, 60.9% (42 of 69) in stimulating acupressure, and 30.1% (25 of 83) in usual care continued to have normal fatigue. At neither time point were the 2 acupressure groups significantly different. Relaxing acupressure, but not stimulating acupressure, showed significant improvements in sleep quality compared with usual care at week 6, but not at week 10. Only relaxing acupressure significantly improved quality of life vs usual care at weeks 6 and 10. CONCLUSIONS AND RELEVANCE Both acupressure arms significantly reduced persistent fatigue compared with usual care, but only relaxing acupressure had significant effects on sleep quality and quality of life. Relaxing acupressure offers a possible low-cost option for managing symptoms. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01281904.
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3.
The effect of shoe type and fatigue on strike index and spatiotemporal parameters of running.
Mann, R, Malisoux, L, Urhausen, A, Statham, A, Meijer, K, Theisen, D
Gait & posture. 2015;(1):91-5
Abstract
We aimed to observe differences in running style parameters and the stride-to-stride coefficient of variation and correlative patterns using detrended fluctuation analysis (DFA) between conventional and first-time minimalistic shoe use. We also aimed to study the effect of fatigue on these parameters. 26 recreational runners were tested using a pressure insole device on a treadmill whilst wearing conventional (CONV) and minimalistic (MIN) shoes. They then performed a prolonged running bout simulating a fatiguing training session, before being tested a second time in both shoe types. Average values of strike index (initial ground contact point on the footsole expressed as a percentage of total sole length) were not significantly different between CONV [25.7±14.6% (unfatigued), 23.1±11.1% (fatigued)] and MIN [28.9±19.1% (unfatigued), 26.7±17.6% (fatigued)] (p=0.501). The fatigued state also yielded a similar strike index compared to the unfatigued state (p=0.661). An overall trend in decreased inter-stride correlative patterns of strike index was observed in MIN compared to CONV (p=0.075). No differences in contact time, flight time, stride time, duty factor, stride length and stride frequency were found between shoe types. A trend in reduced flight time (p=0.078) and therefore increased duty factor (p=0.053) was observed due to fatigue. We conclude that in recreational runners, no meaningful, acute adaptation in running style occurs as a result of first-time MIN use. Similarly, runners were able to maintain their running style after a prolonged running bout.
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4.
Modafinil reduces patient-reported tiredness after sedation/analgesia but does not improve patient psychomotor skills.
Galvin, E, Boesjes, H, Hol, J, Ubben, JF, Klein, J, Verbrugge, SJ
Acta anaesthesiologica Scandinavica. 2010;(2):154-61
Abstract
BACKGROUND Early recovery of patients following sedation/analgesia and anesthesia is important in ambulatory practice. The aim of this study was to assess whether modafinil, used for the treatment of narcolepsy, improves recovery following sedation/analgesia. METHODS Patients scheduled for extracorporeal shock wave lithotripsy were randomly assigned to one of four groups. Two groups received a combination of fentanyl/midazolam with either modafinil or placebo. The remaining groups received remifentanil/propofol with either modafinil or placebo. Modafinil 200 mg was administered to the treatment group patients 1 h before sedation/analgesia. Groups were compared using the digital symbol substitution test (DSST), trail making test (TMT), observer scale of sedation and analgesia (OAA/S) and Aldrete score. Verbal rating scale (VRS) scores for secondary outcome variables e.g. energy, tiredness and dizziness were also recorded before and after treatment. RESULTS Sixty-seven patients successfully completed the study. Groups received similar doses of sedation and analgesic drugs. No statistically significant difference was found for DSST between groups. No significant adverse effects occurred in relation to modafinil. No statistically significant difference between groups was identified for TMT, OAA/S and Aldrete scores. The mean VRS score for tiredness was lesser in the modafinil/fentanyl/midazolam group [1.3 (2.0)] compared with the placebo group [3.8 (2.5)], P=0.02. Such a difference was not found between the remifentanil/propofol groups [placebo 2.6 (2.2) vs. modafinil 3.1(2.7)], p>0.05. Dizziness was greater in the modafinil/remifentanil/propofol group 1.7 (2.0) vs. placebo 0.0 (0.5), p<0.05. CONCLUSION Modafinil reduces patient-reported tiredness after sedation/analgesia but does not improve recovery in terms of objective measures of patient psychomotor skills.
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5.
Sensitivity to change in cognitive performance and mood measures of energy and fatigue in response to differing doses of caffeine or breakfast.
Maridakis, V, Herring, MP, O'Connor, PJ
The International journal of neuroscience. 2009;(7):975-94
Abstract
This double-blind, placebo-controlled, within-subjects (N = 18) experiment compared the sensitivity to change of cognitive performance and mood measures of mental energy following consumption of either 100 or 200-mg caffeine or a 440-calorie breakfast. Breakfast and 200-mg caffeine improved mood and cognitive performance. The sensitivity to change of the measures did not differ in response to any treatment (all p values > .05). The mood and cognitive measures of mental energy used here have similar sensitivity to detecting change in response to a moderate dose of caffeine and breakfast consumption.
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6.
Simulator driving performance, subjective sleepiness and salivary cortisol in a fast-forward versus a slow-backward rotating shift system.
De Valck, E, Quanten, S, Berckmans, D, Cluydts, R
Scandinavian journal of work, environment & health. 2007;(1):51-7
Abstract
OBJECTIVES The objectives of this study were to examine simulator driving and subjective sleepiness after morning, afternoon, and night shifts and to compare these differences, as well as objective stress, between a fast-forward and a slow-backward rotating shift system. METHODS The participants were male volunteers working in a chemical plant, 18 in a slow-backward rotating system and 18 in a fast-forward rotating system. All of the participants performed a driving simulator test and subjectively estimated sleepiness after a night, afternoon, and morning shift. Salivary cortisol samples, as indicators of the objective stress level, at the beginning of the workweek-after the second morning shift-were compared between the two rotating shift systems. RESULTS Lane drifting was higher after a night shift than after an afternoon shift. No effect of rotation system on driving performance could be shown. The subjective sleepiness scores were significantly higher in the slow-backward rotating group than in the fast-forward rotating group. A significant effect of shift type was also observed, with lower levels of sleepiness after the afternoon shift than after the morning and night shifts. Salivary cortisol samples taken at the start of the workweek did not significantly differ between the fast-forward and the slow-backward rotation shift systems. CONCLUSIONS This study indicated that shift type is more important than shift schedule-direction and speed of rotation-in determining driving performance. Performance seemed to be threatened mostly by a night shift and the least by an afternoon shift. In contrast, subjective sleepiness also differed between rotation groups and indicated an advantage of the fast-forward rotation system. The exploratory salivary cortisol measurements suggested that the shift systems studied do not differ in the level of stress they induce, that is to say at the beginning of the workweek.