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L-Glutamine Supplementation Enhances Strength and Power of Knee Muscles and Improves Glycemia Control and Plasma Redox Balance in Exercising Elderly Women.
Amirato, GR, Borges, JO, Marques, DL, Santos, JMB, Santos, CAF, Andrade, MS, Furtado, GE, Rossi, M, Luis, LN, Zambonatto, RF, et al
Nutrients. 2021;(3)
Abstract
We investigated the effects of oral L-glutamine (Gln) supplementation, associated or not with physical exercises, in control of glycemia, oxidative stress, and strength/power of knee muscles in elderly women. Physically active (n = 21) and sedentary (n = 23) elderly women aged 60 to 80 years were enrolled in the study. Plasma levels of D-fructosamine, insulin, reduced (GSH) and oxidized (GSSG) glutathione, iron, uric acid, and thiobarbituric acid-reactive substances (TBARs) (lipoperoxidation product), as well as knee extensor/flexor muscle torque peak and average power (isokinetic test), were assessed pre- and post-supplementation with Gln or placebo (30 days). Higher plasma D-fructosamine, insulin, and iron levels, and lower strength/power of knee muscles were found pre-supplementation in the NPE group than in the PE group. Post-supplementation, Gln subgroups showed higher levels of GSH, GSSG, and torque peak, besides lower D-fructosamine than pre-supplementation values. Higher muscle average power and plasma uric acid levels were reported in the PE + Gln group, whereas lower insulin levels were found in the NPE + Gln than pre-supplementation values. TBARs levels were diminished post-supplementation in all groups. Gln supplementation, mainly when associated with physical exercises, improves strength and power of knee muscles and glycemia control, besides boosting plasma antioxidant capacity of elderly women.
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A Single Dose of Dietary Nitrate Increases Maximal Knee Extensor Angular Velocity and Power in Healthy Older Men and Women.
Coggan, AR, Hoffman, RL, Gray, DA, Moorthi, RN, Thomas, DP, Leibowitz, JL, Thies, D, Peterson, LR
The journals of gerontology. Series A, Biological sciences and medical sciences. 2020;(6):1154-1160
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Abstract
BACKGROUND Aging results in reductions in maximal muscular strength, speed, and power, which often lead to functional limitations highly predictive of disability, institutionalization, and mortality in elderly adults. This may be partially due to reduced nitric oxide (NO) bioavailability. We, therefore, hypothesized that dietary nitrate (NO3-), a source of NO via the NO3- → nitrite (NO2-) → NO enterosalivary pathway, could increase muscle contractile function in older subjects. METHODS Twelve healthy older (age 71 ± 5 years) men and women were studied using a randomized, double-blind, placebo-controlled, crossover design. After fasting overnight, subjects were tested 2 hours after ingesting beetroot juice containing or devoid of 13.4 ± 1.6 mmol NO3-. Plasma NO3- and NO2- and breath NO were measured periodically, and muscle function was determined using isokinetic dynamometry. RESULTS N O 3 - ingestion increased (p < .001) plasma NO3-, plasma NO2-, and breath NO by 1,051% ± 433%, 138% ± 149%, and 111% ± 115%, respectively. Maximal velocity of knee extension increased (p < .01) by 10.9% ± 12.1%. Maximal knee extensor power increased (p < .05) by 4.4% ± 7.8%. CONCLUSIONS Acute dietary NO3- intake improves maximal knee extensor angular velocity and power in older individuals. These findings may have important implications for this population, in whom diminished muscle function can lead to functional limitations, dependence, and even premature death.
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The Effectiveness of Olive Oil in Controlling Morning Inflammatory Pain of Phalanges and Knees Among Women With Rheumatoid Arthritis: A Randomized Clinical Trial.
Hekmatpou, D, Mortaji, S, Rezaei, M, Shaikhi, M
Rehabilitation nursing : the official journal of the Association of Rehabilitation Nurses. 2020;(2):106-113
Abstract
PURPOSE This study aimed to determine the effectiveness of olive oil in controlling morning inflammatory pain of phalanges and knees among women with rheumatoid arthritis. DESIGN This is a randomized clinical trial, which was done in Arak, Iran. METHOD After selecting 60 women based on a convenience sampling method, they were randomly allocated into five groups. A demographic questionnaire, the Visual Analogue Scale, and the Disease Activity Score 28 were completed. After 12 weeks of interventions, the last two scales were again completed. All data were analyzed using t test, Kruskal-Wallis test, and Friedman test. RESULTS The mean age of the women was 40 ± 10.5 years. The result of the Friedman test showed a significant difference (p ≤ .001) among the total mean of groups before and after interventions. The post hoc test (least significant difference [LSD]) showed a significant difference (p ≤ .001) between the mean of Disease Activity Score 28 in the group using olive oil for massaging. Results also showed that there are significant differences (p ≤ .001) among the mean of Visual Analogue Scale rates, among the mean of the number of painful joints, and among the mean of the number of swollen joints after intervention in the five groups. CONCLUSION Applying topical extra virgin olive oil, Piroxicam gel, and paraffin oil; dry massaging; and taking routine drugs alone were all effective in controlling rheumatic arthritis manifestations, respectively. Therefore, applying topical extra virgin olive oil for controlling of inflammatory pain of joints in rheumatic arthritis is recommended. CLINICAL RELEVANCE In comparison with other medical ointments for RA, olive oil has lower expenditure and is findable in many homes.
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Neuromuscular Activity and Muscular Oxygenation Through Different Movement Cadences During In-water and On-land Knee Extension Exercise.
Chien, KY, Kan, NW, Liao, YH, Lin, YL, Lin, CL, Chen, WC
Journal of strength and conditioning research. 2017;(3):750-757
Abstract
Chien, K-Y, Kan, N-W, Liao, Y-H, Lin, Y-L, Lin, C-L, and Chen, W-C. Neuromuscular activity and muscular oxygenation through different movement cadences during in-water and on-land knee extension exercise. J Strength Cond Res 31(3): 750-757, 2017-The purpose of this study was to determine the influence of various knee extension exercise cadences on neuromuscular activation and hemodynamic properties of the quadriceps muscle in water and on land. Seventeen young women participated in this study, and the subjects were randomly allocated to perform loaded knee extension exercises in water and on land at 4 different cadences of 30, 50, 70, and 90 b·min. Heart rate (HR), blood flow (BF), total saturation index (TSI) of oxygen, electromyography (EMG) for the extent of muscular activity, and rate of perceived exertion (RPE) were measured. Response values of HR, BF, TSI, and RPE at each cadence were obtained by subtracting the resting values from the indicator values measured at the respective cadences. We observed that BF, EMG, and RPE in water at 90 b·min were comparable with those on land. The HR and TSI changes were higher in water compared with on land (p = 0.004 and p = 0.013, respectively). In conclusion, we demonstrate that the neuromuscular activity when performing knee extension exercises at 90 b·min in water was comparable with that on land. However, exercising in water at the same cadence evoked higher TSI responses and greater cardiovascular challenges. A knee extension exercise at 90 b·min is the recommended operating speed of rehabilitation in water.
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Drop punt kicking induces eccentric knee flexor weakness associated with reductions in hamstring electromyographic activity.
Duhig, SJ, Williams, MD, Minett, GM, Opar, D, Shield, AJ
Journal of science and medicine in sport. 2017;(6):595-599
Abstract
OBJECTIVES To examine the effect of 100 drop punt kicks on isokinetic knee flexor strength and surface electromyographic activity of bicep femoris and medial hamstrings. DESIGN Randomized control study. METHODS Thirty-six recreational footballers were randomly assigned to kicking or control groups. Dynamometry was conducted immediately before and after the kicking or 10min of sitting (control). RESULTS Eccentric strength declined more in the kicking than the control group (p<0.001; d=1.60), with greater reductions in eccentric than concentric strength after kicking (p=0.001; d=0.92). No significant between group differences in concentric strength change were observed (p=0.089; d=0.60). The decline in normalized eccentric hamstring surface electromyographic activity (bicep femoris and medial hamstrings combined) was greater in the kicking than the control group (p<0.001; d=1.78), while changes in concentric hamstring surface electromyographic activity did not differ between groups (p=0.863; d=0.04). Post-kicking reductions in surface electromyographic activity were greater in eccentric than concentric actions for both bicep femoris (p=0.008; d=0.77) and medial hamstrings (p<0.001; d=1.11). In contrast, the control group exhibited smaller reductions in eccentric than concentric hamstring surface electromyographic activity for bicep femoris (p=0.026; d=0.64) and medial hamstrings (p=0.032; d=0.53). Reductions in bicep femoris surface electromyographic activity were correlated with eccentric strength decline (R=0.645; p=0.007). CONCLUSIONS Reductions in knee flexor strength and hamstring surface electromyographic activity are largely limited to eccentric contractions and this should be considered when planning training loads in Australian Football.
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A randomized controlled trial evaluating methylsulfonylmethane versus placebo to prevent knee pain in military initial entry trainees.
Tennent, DJ, Hylden, CM, Kocher, BK, Aden, JK, Johnson, AE
U.S. Army Medical Department journal. 2017;(3-17):21-25
Abstract
BACKGROUND Methylsulfonylmethane (MSM) is a naturally occurring sulfur containing substance that has been shown to have anti-inflammatory and antioxidative properties. Previous studies using MSM as an oral supplement to improve pain in those patients with knee osteoarthritis have shown superiority compared to placebo. However, these studies are not translatable to active individuals performing high impact activities and have not evaluated MSM as a preventative measure. METHODS A total of 180 subjects ranging in age from 18 to 40 years were enrolled. Subjects were randomized into 2 groups receiving either 3 grams OptiMSM methylsulfonylmethane (Bergstrom Nutrition, Vancouver, WA) or a placebo for 8 weeks. Outcomes measured were the Knee Osteoarthritis Outcome Score (KOOS) and the Profile of Moods States (POMS). RESULTS Three grams of MSM administered daily did not provide significant improvements in the 5 KOOS subscales or the 6 POMS subscales at 30 days or 60 days. CONSLUSION Although 3 grams of MSM daily can be used safely, there does not appear to be a significant improvement in KOOS or POMS.
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Recovery kinetics of knee flexor and extensor strength after a football match.
Draganidis, D, Chatzinikolaou, A, Avloniti, A, Barbero-Álvarez, JC, Mohr, M, Malliou, P, Gourgoulis, V, Deli, CK, Douroudos, II, Margonis, K, et al
PloS one. 2015;(6):e0128072
Abstract
We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12 h, 36 h and 60 h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12 h, 36 h and 60 h after the match. Functional (KFecc/KEcon) and conventional (KFcon/KEcon) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60 h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (P<0.05) at 12 h (both limbs) and 36 h (dominant limb only), b) eccentric and concentric peak torque of knee extensors and flexors declined (P<0.05) in both limbs for 36 h at 60°/s and for 60 h at 180°/s with eccentric peak torque of knee flexors demonstrating a greater (P<0.05) reduction than concentric peak torque, c) strength deterioration was greater (P<0.05) at 180°/s and in dominant limb, d) the functional ratio was more sensitive to match-induced fatigue demonstrating a more prolonged decline. Discriminant and regression analysis revealed that strength deterioration and recovery may be related to the amount of eccentric actions performed during the match and athletes' football-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical conditioning level.
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Mechanical, biochemical, and electromyographic responses to short-term eccentric-concentric knee extensor training in humans.
Váczi, M, Tihanyi, J, Hortobágyi, T, Rácz, L, Csende, Z, Costa, A, Pucsok, J
Journal of strength and conditioning research. 2011;(4):922-32
Abstract
This study examined the effects of short-term eccentric-concentric knee extensor training on mechanical and biochemical variables, myoelectric activity, and muscle soreness. Seventeen men were assigned to either experimental (E, n = 10) or control group (C, n = 7). Group E performed 90 maximal isokinetic eccentric-concentric knee extensor contractions on each of 3 consecutive days (Tr1-Tr3) followed by 1-day rest, and then on 4 more consecutive days (Tr4-Tr7). Peak eccentric torque of each contraction during the training was recorded and averaged for each session (MTr). Maximal isometric torque (M0), eccentric torque (M(ecc)), integrated electromyography (iEMG), plasma creatine kinase (CK), and lactate dehydrogenase (LDH) activities were measured before, immediately, 24, 48, and 72 hours after Tr1, at 1 and 3 days after Tr7. Group C did not train but performed all exercise tests; CK and LDH were measured at 3 time points only. Acutely, M0 and M(ecc) decreased and CK, LDH, and soreness increased more in E than in C 24 hours after Tr1. Chronically, MTr and M0 increased more in E than C by Tr7 and CK, LDH, and muscle soreness gradually decreased by Tr7 whereas iEMG increased more in E than in C after Tr3 through Tr7. High-intensity short-term eccentric-concentric knee extensor exercise training produced immediate reductions in maximal voluntary force. Most likely neural adaptations contributed to rapid recovery and strength adaptations because maximal voluntary force increased by the end of the training protocol in previously trained healthy adults.
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Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans.
Bailey, SJ, Fulford, J, Vanhatalo, A, Winyard, PG, Blackwell, JR, DiMenna, FJ, Wilkerson, DP, Benjamin, N, Jones, AM
Journal of applied physiology (Bethesda, Md. : 1985). 2010;(1):135-48
Abstract
The purpose of this study was to elucidate the mechanistic bases for the reported reduction in the O(2) cost of exercise following short-term dietary nitrate (NO(3)(-)) supplementation. In a randomized, double-blind, crossover study, seven men (aged 19-38 yr) consumed 500 ml/day of either nitrate-rich beet root juice (BR, 5.1 mmol of NO(3)(-)/day) or placebo (PL, with negligible nitrate content) for 6 consecutive days, and completed a series of low-intensity and high-intensity "step" exercise tests on the last 3 days for the determination of the muscle metabolic (using (31)P-MRS) and pulmonary oxygen uptake (Vo(2)) responses to exercise. On days 4-6, BR resulted in a significant increase in plasma [nitrite] (mean +/- SE, PL 231 +/- 76 vs. BR 547 +/- 55 nM; P < 0.05). During low-intensity exercise, BR attenuated the reduction in muscle phosphocreatine concentration ([PCr]; PL 8.1 +/- 1.2 vs. BR 5.2 +/- 0.8 mM; P < 0.05) and the increase in Vo(2) (PL 484 +/- 41 vs. BR 362 +/- 30 ml/min; P < 0.05). During high-intensity exercise, BR reduced the amplitudes of the [PCr] (PL 3.9 +/- 1.1 vs. BR 1.6 +/- 0.7 mM; P < 0.05) and Vo(2) (PL 209 +/- 30 vs. BR 100 +/- 26 ml/min; P < 0.05) slow components and improved time to exhaustion (PL 586 +/- 80 vs. BR 734 +/- 109 s; P < 0.01). The total ATP turnover rate was estimated to be less for both low-intensity (PL 296 +/- 58 vs. BR 192 +/- 38 microM/s; P < 0.05) and high-intensity (PL 607 +/- 65 vs. BR 436 +/- 43 microM/s; P < 0.05) exercise. Thus the reduced O(2) cost of exercise following dietary NO(3)(-) supplementation appears to be due to a reduced ATP cost of muscle force production. The reduced muscle metabolic perturbation with NO(3)(-) supplementation allowed high-intensity exercise to be tolerated for a greater period of time.
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Knee strength maintained despite loss of lean body mass during weight loss in older obese adults with knee osteoarthritis.
Wang, X, Miller, GD, Messier, SP, Nicklas, BJ
The journals of gerontology. Series A, Biological sciences and medical sciences. 2007;(8):866-71
Abstract
BACKGROUND The effects of weight loss on muscle function in older adults have not been well studied. This study determined the effects of a 6-month weight-loss intervention on muscle strength and quality in older obese adults with knee osteoarthritis. METHODS Participants were randomized to a weight loss (WL) (n = 44, 70 +/- 6 years) or weight stable (WS) (n = 43, 69 +/- 6 years) group. The WL intervention consisted of weekly educational meetings, a meal replacement diet, and a three-session-per-week structured exercise program to achieve 10%-12% weight loss. The WS intervention included bimonthly group meetings and newsletters. Body composition and knee extensor strength were measured at baseline and after intervention. RESULTS The WL group decreased body weight, lean body mass, fat mass, and percent body fat (p <.001 for all). Concentric extension strength increased 25% in WL (p >.05), whereas eccentric extension decreased 6% in WS (p =.028). Concentric muscle quality (strength per kg body weight or lean body mass) increased in WL (p <.05), whereas eccentric muscle quality decreased in WS (p <.05). Changes in lean body mass and fat mass were inversely associated with changes in most muscle strength and quality measures (p <.05). Men and women did not differ in response to the intervention in knee strength outcomes. CONCLUSIONS Hypocaloric dieting in combination with exercise training had beneficial effects on muscle strength/quality, despite loss of lean body mass in this sample of older men and women. Greater fat loss was associated with greater gains in muscle strength and quality. More studies are needed regarding the mechanisms by which loss of fat mass increases muscle strength and quality.