Displaying publications 21 - 29 of 29 in total

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  1. Khong TK, Selvanayagam VS, Hamzah SH, Yusof A
    J Appl Physiol (1985), 2018 10 01;125(4):1021-1029.
    PMID: 29975601 DOI: 10.1152/japplphysiol.00221.2018
    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.
    Matched MeSH terms: Physical Endurance*
  2. Bandyopadhyay A, Ping FW, Keong CC
    J Hum Ergol (Tokyo), 2011 Dec;40(1-2):63-72.
    PMID: 25665208 DOI: 10.11183/jhe.40.63
    Acute supplementation of Panax ginseng (PG) is known not to impose any significant effect on endurance performance of recreational Malaysian runners, while caffeine augments the ergogenic property of some herbs. The present study was aimed to examine the effects of acute supplementation of caffeine and PG on endurance running performance in a hot and humid condition. Nine heat adapted Malaysian recreational runners (age : 25.4 ± 6.9 years, body mass : 57.6 ± 8.4 kg; body height : 168.3 ± 7.6 cm) ingested either placebo or combined dose of 5 mg x kg(-1) of body weight of caffeine and 200 mg of PG one hour before the running on treadmill at 70% of VO2(max) in this placebo-controlled double blind randomised study in a laboratory environment of 31 degrees C and 70% relative humidity. They drank 3 ml x kg(-1) of body weight of cool water every 20 minutes during the exercise to prevent dehydration. Blood samples were withdrawn and oxygen uptake was recorded every 20 minutes while heart rate, core body temperature, skin temperature and ratings of perceived exertion (RPE) were recorded every 10 minutes during the trials. Endurance time was significantly different (P < 0.05) between experimental and placebo trials. Heart rate, skin temperature, core body temperature, oxygen uptake, RPE, plasma insulin, glucose, free fatty acid and lactate levels during the endurance exercise did not show any significant difference between the trials. Thus, we conclude that combined and acute supplementation of caffeine and PG in the said doses improved the endurance running performance of the heat-adapted male recreational runners.
    Matched MeSH terms: Physical Endurance/drug effects*
  3. Lane SC, Camera DM, Lassiter DG, Areta JL, Bird SR, Yeo WK, et al.
    J Appl Physiol (1985), 2015 Sep 15;119(6):643-55.
    PMID: 26112242 DOI: 10.1152/japplphysiol.00857.2014
    We determined the effects of "periodized nutrition" on skeletal muscle and whole body responses to a bout of prolonged exercise the following morning. Seven cyclists completed two trials receiving isoenergetic diets differing in the timing of ingestion: they consumed either 8 g/kg body mass (BM) of carbohydrate (CHO) before undertaking an evening session of high-intensity training (HIT) and slept without eating (FASTED), or consumed 4 g/kg BM of CHO before HIT, then 4 g/kg BM of CHO before sleeping (FED). The next morning subjects completed 2 h of cycling (120SS) while overnight fasted. Muscle biopsies were taken on day 1 (D1) before and 2 h after HIT and on day 2 (D2) pre-, post-, and 4 h after 120SS. Muscle [glycogen] was higher in FED at all times post-HIT (P < 0.001). The cycling bouts increased PGC1α mRNA and PDK4 mRNA (P < 0.01) in both trials, with PDK4 mRNA being elevated to a greater extent in FASTED (P < 0.05). Resting phosphorylation of AMPK(Thr172), p38MAPK(Thr180/Tyr182), and p-ACC(Ser79) (D2) was greater in FASTED (P < 0.05). Fat oxidation during 120SS was higher in FASTED (P = 0.01), coinciding with increases in ACC(Ser79) and CPT1 as well as mRNA expression of CD36 and FABP3 (P < 0.05). Methylation on the gene promoter for COX4I1 and FABP3 increased 4 h after 120SS in both trials, whereas methylation of the PPARδ promoter increased only in FASTED. We provide evidence for shifts in DNA methylation that correspond with inverse changes in transcription for metabolically adaptive genes, although delaying postexercise feeding failed to augment markers of mitochondrial biogenesis.
    Matched MeSH terms: Physical Endurance/physiology*
  4. Ooi FK, Singh R, Singh HJ, Umemura Y
    Osteoporos Int, 2009 Jun;20(6):963-72.
    PMID: 18839049 DOI: 10.1007/s00198-008-0760-6
    SUMMARY: This study determines the minimum level of exercise required to maintain 8 weeks of jumping exercise-induced bone gains in rats. It was found that the minimum level of exercise required for maintaining the different exercise-induced bone gains varied between 11% and 18% of the initial exercise intensity.

    INTRODUCTION: This study ascertains the minimum level of follow-up exercise required to maintain bone gains induced by an 8-week jumping exercise in rats.

    METHODS: Twelve groups of 12-week old rats (n = 10 rats per group) were given either no exercise for 8 (8S) or 32 weeks (32S), or received 8 weeks of standard training program (8STP) that consisted of 200 jumps per week, given at 40 jumps per day for 5 days per week, followed by 24 weeks of exercise at loads of either 40 or 20 or 10 jumps per day, for either 5, or 3, or 1 day/week. Bone mass, strength, and morphometric properties were measured in the right tibia. Data were analyzed using one-way analyses of variance.

    RESULTS: Bone mass, strength, mid-shaft periosteal perimeter and cortical area were significantly (p < 0.05) higher in the rats given 8STP than that in the 8S group. The minimal level of exercise required to maintain the bone gains was 31, 36, 25, and 21 jumps per week for mass, strength, periosteal perimeter and cortical area, respectively.

    CONCLUSIONS: Eight weeks of jumping exercise-induced bone gains could be maintained for a period of 24 weeks with follow-up exercise consisting of 11% to 18% of the initial exercise load.

    Matched MeSH terms: Physical Endurance
  5. Razaob, N.A, Ab. Rahman, N.N.A., Mohd Nordin, N.A., Ee, F.S.Y., Lee, J.H., Doherty, P.
    Medicine & Health, 2018;13(2):83-94.
    MyJurnal
    Chair based exercise (CBE) is an exercise alternative for older adults in ensuring safety during exercise. Its evidence of effectiveness is currently limited to frail older adults or those with acute medical conditions or terminal illnesses. Given higher exercise difficulty level, CBE could benefit healthier older adults and can be an exercise option for this population. This study was designed to evaluate the outcome of a CBE on physical performance and quality of life in community-dwelling older women in Malaysia. A total of 18 older women (mean age 66.78 + 4.60 years) completed CBE at twice-per-week for eight weeks. Exercise outcomes were measured using six minutes’ walk test (6MWT), five times sit to stand test (FTSTS) and hand-held dynamometer for physical endurance, functional lower limb strength and grip strength, respectively. A Malay version of the World Health Organization quality of life scale (WHOQOL-BREFMalay) was used to measure the health status and QOL of the participants. All data were analysed with the use of inferential statistics, with significance level set at p
    Matched MeSH terms: Physical Endurance
  6. Singh R, Singh HJ, Sirisinghe RG
    Singapore Med J, 1995 Apr;36(2):169-72.
    PMID: 7676261
    Aerobic capacity (VO2max) and lung capacities were measured in 66 healthy females ranging in age from 13 to 49 years. Forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were measured using a dry spirometer and Wrights peak flow meter respectively. Cardiopulmonary parameters were obtained from a progressive ergocycle test to exhaustion. Mean FVC and PEFR obtained were 2.73 +/- 0.07 L and 412 +/- 8.5 L/min respectively. FVC correlated negatively with age in subjects from the 3rd to 5th decade of age (r = 0.38, p < 0.05). Mean VO2max was 43.2 +/- 0.9 ml/kg/min in the 2nd decade compared to 30.3 +/- 0.7 ml/kg/min in the fifth decade. Regression analysis revealed an age related decline in VO2max of 0.45 +/- 0.8 ml/kg/min/year, which was found to be somewhat higher compared to other studies.
    Matched MeSH terms: Physical Endurance
  7. Hussain J, Sundaraj K, Subramaniam ID
    PLoS One, 2020;15(1):e0228089.
    PMID: 31999750 DOI: 10.1371/journal.pone.0228089
    INTRODUCTION: Cognitive stress (CS) changes the peripheral attributes of a muscle, but its effect on multi-head muscles has not been investigated. The objective of the current research was to investigate the impact of CS on the three heads of the triceps brachii (TB) muscle.

    METHODS: Twenty-five young and healthy university students performed a triceps push-down exercise at 45% one repetition maximum (1RM) with and without CS until task failure, and the rate of fatigue (ROF), endurance time (ET) and number of repetitions (NR) for both exercises were analyzed. In addition, the first and last six repetitions of each exercise were considered non-fatiguing (NF) and fatiguing (Fa), respectively, and the root mean square (RMS), mean power frequency (MPF) and median frequency (MDF) for each exercise repetition were evaluated.

    RESULTS: The lateral and long head showed significant differences (P<0.05) in the ROF between the two exercises, and all the heads showed significant (P<0.05) differences in the RMS between the two exercises under NF conditions. Only the long head showed a significant difference (P<0.05) in the MPF and MDF between the two exercises. CS increases the ET (24.74%) and NR (27%) of the exercise. The three heads showed significant differences (P<0.05) in the RMS, MPF and MDF under all exercise conditions.

    CONCLUSION: A lower ROF was obtained with CS. In addition, the RMS was found to be better approximator of CS, whereas MPF and MDF were more resistant to the effect of CS. The results showed that the three heads worked independently under all conditions, and the non-synergist and synergist head pairs showed similar behavior under Fa conditions. The findings from this study provide additional insights regarding the functioning of each TB head.

    Matched MeSH terms: Physical Endurance
  8. Lew LC, Hor YY, Jaafar MH, Lau ASY, Ong JS, Chuah LO, et al.
    Benef Microbes, 2019 Dec 09;10(8):883-892.
    PMID: 31965837 DOI: 10.3920/BM2019.0058
    This study aimed to evaluate the anti-ageing effects of different strains of lactobacilli putative probiotics on an ageing rat model as induced by D-galactose and a high fat diet. Male Sprague-Dawley rats were fed with high fat diet (54% kcal fat) and injected with D-galactose daily for 12 weeks to induce ageing. The effects of putative probiotic strains on age-related impairment such as telomere length, plasma lipid peroxidation, hepatic 5'adenosine monophosphate-activated protein kinase (AMPK) expression, as well as endurance performance were evaluated. Administration of statin, Lactobacillus plantarum DR7 (LP-DR7), Lactobacillus fermentum DR9 (LF-DR9), and Lactobacillus reuteri 8513d (LR-8513d) significantly reduced the shortening of telomere and increased the expression of AMPK subunit-α1 (P<0.05). Plasma lipid peroxidation was lower (P<0.05) in groups administered with statin and LF-DR9 as compared to the control. AMPK subunit-α2 was elevated in rats administered with LP-DR7 as compared to the control (P<0.05). Using an in vivo ageing rat model, the current study has illustrated the potentials of lactobacilli putative probiotics in alleviation of age-related impairment in a strain-dependent manner.
    Matched MeSH terms: Physical Endurance/drug effects
  9. Abdullah MF, Nor NM, Mohd Ali SZ, Ismail Bukhary NB, Amat A, Latif LA, et al.
    Ann Acad Med Singap, 2011 Apr;40(4):168-78.
    PMID: 21678002
    INTRODUCTION: Diabetes mellitus (DM) is a chronic disease that is prevalent in many countries. The prevalence of DM is on the rise, and its complications pose a heavy burden on the healthcare systems and on the patients' quality of life worldwide.

    MATERIALS AND METHODS: This is a multicentre, cross-sectional study involving 5 Health Clinics conducted by Family Medicine Specialists in Malaysia. Convenience sampling of 100 respondents with DM were selected. The International Classifi cation of Functioning, Disability and Health (ICF) based measures were collected using the Comprehensive Core Set for DM. SF-36 and self-administered forms and comorbidity questionnaire (SCQ) were also used.

    RESULTS: Ninety-seven percent had Type 2 DM and 3% had Type 1 DM. The mean period of having DM was 6 years. Body functions related to physical health including exercise tolerance (b455), general physical endurance (b4550), aerobic capacity (b4551) and fatiguability (b4552) were the most affected. For body structures, the structure of pancreas (s550) was the most affected. In the ICF component of activities and participation, limitation in sports (d9201) was the highest most affected followed by driving (d475), intimate relationships (d770), handling stress and other psychological demands (d240) and moving around (d455). Only 7% (e355 and e450) in the environmental category were documented as being a relevant factor by more than 90% of the patients.

    CONCLUSION: The content validity of the comprehensive ICF Core set DM for Malaysian population were identified and the results show that physical and mental functioning were impaired in contrast to what the respondents perceived as leading healthy lifestyles.

    Matched MeSH terms: Physical Endurance
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