instantaneous feedback, improve test site flexibility, and be a useful alternative to laboratory measures. Handgrip strength (HGS) is an often-used assessment of overall strength in older adults in part because it is easy to administer, standards have been developed for the older population, and strength of the
Jennifer J. Sherwood, Cathy Inouye, Shannon L. Webb, and Jenny O
Oriana Wong, Keiko Marshall, Marc Sicova, Nanci S. Guest, Bibiana García-Bailo, and Ahmed El-Sohemy
of caffeine among athletes, its effects on strength and power performance remain inconsistent ( Duncan et al., 2013 ; Grgic et al., 2020 ; Sabol et al., 2019 ). For example, 5 mg/kg of caffeine had no effect on handgrip strength in 14 male judo athletes ( da Silva Athayde et al., 2018 ), but
muscle mass is associated with reduced strength ( Kamel, 2003 ). Handgrip strength is a simple and reliable test of physical fitness and is a predictor of overall muscle strength, sarcopenia, and physical health ( Bohannon, 2015 ). Weak handgrip strength is associated with all-cause mortality and
Mehrez Hammami, Rodrigo Ramirez-Campillo, Nawel Gaamouri, Gaith Aloui, Roy J. Shephard, and Mohamed Souhaiel Chelly
(Microgate, Bolzano, Italy). The second day was devoted to jumping (squat jump, countermovement jump, countermovement jump with arms, and horizontal 5-jump tests) followed by dominant and nondominant handgrip strength assessments. On the third day, anthropometric measurements were followed by determinations
Jan Kodejška, Jiří Baláš, and Nick Draper
and 8°C CWI on repeat handgrip performance to failure. Methods A total of 32 sport climbers (15 males: age 27.7 = [10.2] y; body mass = 71.0 [9.3] kg; height = 178.3 [9.7] cm; 17 females: age = 26.3 [4.6] y; body mass = 57.7 [5.6] kg; height = 166.4 [5.7] cm) volunteered for the study. Self
Takashi Abe, Jeremy P. Loenneke, Robert S. Thiebaud, and Mark Loftin
There is a general agreement that handgrip strength (HGS) is an important criterion for diagnosing sarcopenia in older adults 1 , 2 because the age-related decline in HGS is a simple and powerful predictor of future disability and mortality. 3 , 4 However, one potential issue is that studies
Javier Abian-Vicen, Adrián Castanedo, Pablo Abian, Cristina Gonzalez-Millan, Juan José Salinero, and Juan Del Coso
The aim was to analyze the influence of competitive round on muscle strength, body-fluid balance, and renal function in elite badminton players during a real competition. Body mass, jump height during a countermovement jump, handgrip force, and urine samples were obtained from 13 elite badminton players (6 men and 7 women) before and after the 2nd-round and quarterfinal matches of the national Spanish badminton championship. Sweat rate was determined by using prematch-to-postmatch body-mass change and by weighing individually labeled fluid bottles. Sweat rates were 1.04 ± 0.62 and 0.98 ± 0.43 L/h, while rehydration rate was 0.69 ± 0.26 and 0.91 ± 0.52 L/h for the 2nd round and quarterfinals, respectively. Thus, dehydration was 0.47% ± 1.03% after the 2nd round and 0.23% ± 0.43% after the quarterfinals. There were no differences in prematch-to-postmatch jump height, but jump height was reduced from 37.51 ± 8.83 cm after the 2nd-round game to 34.82 ± 7.37 cm after the quarterfinals (P < .05). No significant differences were found in handgrip force when comparing prepost matches or rounds, although there were significant differences between dominant and nondominant hands (P < .05). The succession of rounds caused the appearance of proteinuria, hematuria, glycosuria, and higher nitrite and ketone concentrations in urine. Rehydration patterns during a real badminton competition were effective to prevent dehydration. A badminton match did not affect jump height or handgrip force, but jump height was progressively reduced by the competitive round. Badminton players’ renal responses reflected diminished renal flux due to the high-intensity nature of this racket sport.
Youngdeok Kim, Joaquin U. Gonzales, and P. Hemachandra Reddy
muscle mass with aging ( Abe, Thiebaud, & Loenneke, 2016 ; Hughes et al., 2001 ). Maximal isometric handgrip strength is a simple and noninvasive measure of skeletal muscle strength that is recommended by the European Working Party on Sarcopenia in Older People ( Cruz-Jentoft et al., 2010 ). Handgrip
Jorge R. Fernandez-Santos, Jonatan R. Ruiz, Jose Luis Gonzalez-Montesinos, and Jose Castro-Piñero
The aim of this study was to analyze the reliability and the validity of the handgrip, basketball throw and pushups tests in children aged 6–12 years. One hundred and eighty healthy children (82 girls) agreed to participate in this study. All the upper body muscular fitness tests were performed twice (7 days apart) whereas the 1 repetition maximum (1RM) bench press test was performed 2 days after the first session of testing. All the tests showed a high reproducibility (ICC > 0.9) except the push-ups test (intertrial difference = 0.77 ± 2.38, p < .001 and the percentage error = 9%). The handgrip test showed the highest association with 1RM bench press test (r = .79, p < .01; R 2 = .621). In conclusion the handgrip and basketball throw tests are shown as reliable and valid tests to assess upper body muscular strength in children. More studies are needed to assess the validity and the reliability of the upper body muscular endurance tests in children.
Leonardo F. Ferreira, Kenneth S. Campbell, and Michael B. Reid
N-acetylcysteine (NAC) is a thiol donor with antioxidant properties that has potential use as an ergogenic aid. However, NAC is associated with adverse reactions that limit its use in humans.
The authors evaluated NAC efficacy as a thiol donor before handgrip exercise, measuring changes in serum cysteine and glutathione status and recording adverse reactions in adult subjects across a range of doses.
Healthy individuals ingested NAC capsules (9 ± 2 or 18 ± 4 mg/kg) or solution (0, 35, 70, or 140 mg/kg). Venous blood samples were collected and subjects answered a questionnaire about adverse reactions.
Low doses of NAC (capsules) did not affect plasma cysteine or glutathione or cause adverse reactions. Adverse reactions to NAC solution were predominantly mild and gastrointestinal (GI). Intensity of GI reactions to 140 mg/kg NAC was significantly higher than placebo (in a.u., 0.67 ± 0.16 vs. 0.07 ± 0.04; p < .05). Plasma cysteine concentration increased with NAC dose from 9.3 ± 0.7 μM (placebo) to 65.3 ± 6.7 μM (140 mg/kg); however, there was no difference (p > .05) in plasma cysteine for 70 mg/kg vs. 140 mg/kg. Similar increases were observed for the ratio of cysteine to total cysteine, which was directly related to handgrip exercise performance. Plasma glutathione was elevated and oxidized glutathione diminished (p < .05) with NAC 140 mg/kg vs. placebo.
NAC effects on plasma thiols are maximized by oral administration of 70 mg/kg, a dose that does not cause significant adverse reactions.