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Internal loads, but not external loads and fatigue, are similar in young and middle-aged resistance trained males during high volume squatting exercise.(MDPI Basel, 2018-08-22)Little is known about the internal and external loads experienced during resistance exercise, or the subsequent fatigue-related response, across different age groups. This study compared the internal (heart rate, OMNI ratings of perceived exertion (RPE), session RPE) and external loads (peak velocity and power and volume load) during high volume squatting exercise (10 10 at 60% one-repetition maximum (1RM)) and the fatigue-related response (maximal voluntary contraction (MVC), voluntary activation (VA), resting doublet force, peak power, and blood lactate) in young (n = 9; age 22.3 1.7 years) and middle-aged (n = 9; age 39.9 6.2 years) resistance-trained males. All internal load variables and peak velocity illustrated unclear differences between groups during exercise. Peak power and volume load were likely higher in the young group compared to their middle-aged counterparts. The unclear differences in MVC, VA and blood lactate between groups after exercise were accompanied by very likely greater decrements in resting doublet force and peak power at 20 and 80% 1RM in the middle-aged group compared to the young group. These data indicate that internal load is not different between young and middle-aged resistance-trained males, though certain external load measures and the fatigue response are.
An analysis of the three-dimensional kinetics and kinematics of maximal effort punches among amateur boxers.(Routledge, 2018-09-27)The purpose of this study was to quantify the 3D kinetics and kinematics of six punch types among amateur boxers. Fifteen males (age: 24.9 ± 4.2 years; stature: 1.78 ± 0.1 m; body mass: 75.3 ± 13.4 kg; boxing experience: 6.3 ± 2.8 years) performed maximal effort punches against a suspended punch bag during which upper body kinematics were assessed via a 3D motion capture system, and ground reaction forces (GRF) of the lead and rear legs via two force plates. For all variables except elbowjoint angular velocity, analysis revealed significant (P < 0.05) differences between straight, hook and uppercut punches. The lead hook exhibited the greatest peak fist velocity (11.95 ± 1.84 m/s), the jab the shortest delivery time (405 ± 0.15 ms), the rear uppercut the greatest shoulder-joint angular velocity (1069.8 ± 104.5°/s), and the lead uppercut the greatest elbow angular velocity (651.0 ± 357.5°/s). Peak resultant GRF differed significantly (P < 0.05) between rear and lead legs for the jab punch only. Whilst these findings provide novel descriptive data for coaches and boxers, future research should examine if physical and physiological capabilities relate to the key biomechanical qualities associated with maximal punching performance.
A comparison of the FitroDyne and GymAware rotary encoders for quantifying peak and mean velocity during traditional multi-jointed exercises(National Strength and Conditioning Association, 2018-11-01)The FitroDyne and GymAware rotary encoders are being increasingly used in resistance training to monitor movement velocity, but how closely their velocity outcomes agree is unknown. Consequently, this study aimed to determine the level of agreement between the FitroDyne and GymAware for the assessment of movement velocity in three resistance training exercises. Fifteen males performed three repetitions of bench press, back squat and bent-over-row exercises at 10% one repetition maximum increments (from 20 to 80%). For each repetition, the FitroDyne and GymAware recorded peak and mean barbell velocity (cm.s-1). Though strongly correlated (r = 0.79 to 1.00), peak velocity values for the GymAware were significantly lower than the FitroDyne for all exercises and loads. Importantly, the random errors between the devices, quantified via Bland and Altman's 95% limits of agreement, were unacceptable, ranging from ± 3.8 to 25.9 cm.s-1. Differences in mean velocity were smaller (and non-significant for most comparisons) and highly correlated (r = 0.86 to 1.00) between devices. Notwithstanding smaller random errors than for the peak values, mean values still reflected poor agreement (random errors between ± 2.1 to 12.0 cm.s-1). These findings suggest that the FitroDyne and GymAware cannot record peak or mean velocity with acceptable agreement, and should neither be employed interchangeably nor their data compared.
Antibacterial activity of Manuka honey and its components: An overview(AIMS Press, 2018-11-27)The importance of honey for medicinal purposes is well documented in some of the world’s oldest literature. Honey is well known and studied for its antimicrobial properties. The medicinal properties in honey originate from the floral source used by bees. Manuka honey is a dark monofloral honey rich in phenolic content, and currently it is gaining much attention for its antimicrobial activity. Researchers have found that honey is effective against a wide range of pathogens. The antibacterial potency of Manuka honey was found to be related to the Unique Manuka Factor (UMF) rating, which is correlated with the methylglyoxal and total phenols content. It is reported that different types of Manuka honey have differing effects and Gram-negative bacteria are more resistant than Gram-positive bacteria. Bacterial resistance to honey as antimicrobial agent has yet to be identified, possibly due to the presence of a complex mixture of methylglyoxal and other components. Honey is also reported to alter a bacterium’s shape and size through septal ring alteration, which affects cell morphology and growth. Research has shown that Manuka honey of different UMF values has medicinal properties of interest and it can be beneficial when used as a combination treatment with other antimicrobial agents
Gestural repertoire size is associated with social proximity measures in wild chimpanzees.(2019-02-01)Studying the communication systems of primates can provide insights into the evolutionary origins of human language. Some theories propose that language evolved to help meet the demands of managing complex social relationships. Examining the associations between sociality and communication in the great apes can help to identify the specific selection pressures that may have been important for language evolution. In particular, gestural communication is believed to be important because it is a relatively recent trait seen only in primates and particularly in the great apes. However, the extent to which more complex gestural communication plays a role in managing social relationships, as compared to less complex gestural communication, is not well understood. Using social network analysis, we examined the association between complex gesturing (indexed as repertoire size) and complexity of social relationships indexed as proximity (the duration of time spent within 10 m, per hour spent in same party) in wild chimpanzees (Pan troglodytes schweinfurthii). Repertoire size (the total number of gesture types a focal subject produced toward other individuals) and dyadic repertoire size (the number of gesture types produced toward the dyad partner, per hour spent within 10 meters) were positively associated with proximity at the level of the group (centrality in the proximity network) and the dyad (proximity duration between dyads), respectively. Further, the repertoire size of visual and auditory short-range gestures was positively associated with proximity, while the repertoire size of tactile gesture was negatively associated with proximity. Overall these results suggest that gestural repertoire size has important implications for maintaining social relationships in wild chimpanzees and more broadly that gestural communication may have played an important role in language evolution. [Abstract copyright: © 2019 Wiley Periodicals, Inc.]