Acute changes in motor unit discharge property after concentric versus eccentric contraction exercise in knee extensor.

This study aimed to investigate the motor unit firing property immediately after concentric or eccentric contraction exercise. Eighteen healthy men performed repetitive maximal isokinetic knee extension exercises with only concentric or eccentric contraction until they exerted less than 80% of the baseline strength. Before and after the fatiguing exercise, high-density surface electromyography of the vastus lateralis was recorded during submaximal ramp-up isometric contraction and individual motor units were identified.

Neuromuscular characteristics during weight loss in a professional boxer: a case study.

It is important to understand the effects of rapid changes in weight on neuromuscular functions of combat athletes. The purpose of this case study was to investigate time-course changes in muscle strength, muscle size, and neural input during rapid weight loss in a professional boxer. One professional male boxer (26 yr) participated in two matches during measurements: welterweight (66.

Critical Power, Work Capacity, and Recovery Characteristics of Team-Pursuit Cyclists.

Purpose: Leading a 4-km team pursuit (TP) requires high-intensity efforts above critical power (CP) that deplete riders' finite work capacity (W'), whereas riders following in the aerodynamic draft may experience some recovery due to reduced power demands. This study aimed to determine how rider ability and CP and W' measures impact TP performance and the extent to which W' can reconstitute during recovery positions in a TP race.

Methods: Three TP teams, each consisting of 4 males, completed individual performance tests to determine their CP and W'.

Percutaneous electrical stimulation-induced muscle contraction prevents the decrease in ribosome RNA and ribosome protein during pelvic hindlimb suspension.

Skeletal muscle unloading leads to muscle atrophy. Ribosome synthesis has been implicated as an important skeletal muscle mass regulator owing to its translational capacity. Muscle unloading induces a reduction in ribosome synthesis and content, with muscle atrophy.

The Effects of Blackcurrant and Caffeine Combinations on Performance and Physiology During Repeated High-Intensity Cycling.

Blackcurrant juices and extracts containing anthocyanin may provide ergogenic benefits to sports performance. However, there are no studies examining the effects of coingestion of blackcurrant and caffeine. This investigation examined the effects of acute supplementation with a proprietary blackcurrant beverage administered in isolation or in combination with caffeine on repeated high-intensity cycling.

COVID-19 Lockdown in New Zealand: Perceived Stress and Wellbeing among International Health Students Who Were Essential Frontline Workers.

This study examined the stresses and wellbeing of international postgraduate health and nursing students at a tertiary education institute in New Zealand who were mainly essential frontline healthcare workers during the COVID-19 lockdown. Quantitative and qualitative data were collected by purposeful sampling ( = 43). The study utilised a cross-sectional survey, along with the Short Form of Cohen's Perceived Stress Scale (PSS-10), adapted for the COVID-19 lockdown, and followed by semi-structured individual interviews.

Influence of Menstrual Cycle on Leukocyte Response Following Exercise-Induced Muscle Damage.

We investigated the influence of the menstrual cycle (MC) on leukocyte response after exercise-induced muscle damage (EIMD). During the early follicular (E-FP, = 12) or mid-luteal phase (M-LP, = 12), 24 untrained females with eumenorrhea performed 60 eccentric exercises using nondominant arms. Blood samples were collected at pre- and 4, 48, and 96 h postexercise to analyze estradiol and progesterone concentrations, leukocyte count and fractionation, and creatine kinase (CK) activity.

Does resistance exercise lifting velocity change with different rest intervals?

Background: In this study, we examined the sex difference of the effect of rest intervals on lifting velocity during resistance exercise.

Methods: Twenty-two trained subjects (11 men and 11 women) were included. Each protocol consisted of 3 sets of 10 repetitions at 70% of 1- repetition maximum (1RM) with rest intervals of 90 s (R90), 150 s (R150), and 240 s (R240) in a crossover design.

Influence of menstrual cycle on muscle glycogen utilization during high-intensity intermittent exercise until exhaustion in healthy women.

The present study investigated the effects of the menstrual cycle on muscle glycogen and circulating substrates during high-intensity intermittent exercise until exhaustion in healthy women who habitually exercised. In total, 11 women with regular menstrual cycles completed three tests, which comprised the early follicular phase (E-FP), late follicular phase (L-FP), and luteal phase (LP) of the menstrual cycle. High-intensity intermittent exercise until exhaustion was performed on each test day.

Effects of Lactate Administration on Mitochondrial Respiratory Function in Mouse Skeletal Muscle.

Recent evidence has shown that mitochondrial respiratory function contributes to exercise performance and metabolic health. Given that lactate is considered a potential signaling molecule that induces mitochondrial adaptations, we tested the hypothesis that lactate would change mitochondrial respiratory function in skeletal muscle. Male ICR mice (8 weeks old) received intraperitoneal injection of PBS or sodium lactate (1 g/kg BW) 5 days a week for 4 weeks.

The Immediate and Lasting Effects of Resident Summer Camp on Movement Behaviors Among Children.

This study aims to examine the immediate and lasting effects of resident summer camp on movement behaviors among children with repeated pre-, during-, and post-intervention measurements. In total, 21 children (aged 10.3 ± 1.

Influence of the Menstrual Cycle on Muscle Glycogen Repletion After Exhaustive Exercise in Eumenorrheic Women.

Matsuda, T, Takahashi, H, Nakamura, M, Ogata, H, Kanno, M, Ishikawa, A, and Sakamaki-Sunaga, M. Influence of the menstrual cycle on muscle glycogen repletion after exhaustive exercise in eumenorrheic women. J Strength Cond Res 37(4): e273-e279, 2023-The purpose of this study was to investigate the effect of the menstrual cycle on muscle glycogen repletion postexercise.

Can physical activity be simplified for health benefit?

Aim: Physical activity (PA) offers protective benefits against at least 25 chronic conditions including psychological stress. The health benefits of PA may be largely attributed to improvements in cardiorespiratory fitness (CRF). However, current guidelines based on PA duration and intensity are controversial, and both are prone to measurement error.

Influence of ultrasound focus depth on the association between echo intensity and intramuscular adipose tissue.

Introduction/aims: Attenuation of the ultrasound (US) wave is a serious limitation of echo intensity (EI) on B-mode US. The aim of this study was to determine whether the focus depth of US images influences the depth-dependent attenuation of EI and the relationship between EI and intramuscular adipose tissues (IntraMAT).

Methods: The rectus femoris (RF) and vastus intermedius (VI) of the right thigh were studied in 135 adults (92 older, 43 younger).

Risky Play and Social Behaviors among Japanese Preschoolers: Direct Observation Method.

While limited evidence is available, preliminary studies highlight the potential health benefits of risky play. However, most of the studies have used subjective methods (i.e.

The Effect of Co-Ingestion of Carbohydrate with Milk after Exercise in Healthy Women: Study Considering the Menstrual Cycle.

This study aimed to assess the effects of co-ingestion of carbohydrate with milk (MILK) and isocaloric carbohydrate beverage (CHO) on post-exercise recovery and subsequent exercise capacity, considering the menstrual cycle. This study included 12 women with regular menstrual cycles who completed four test days, which started with glycogen-depleting exercise using a cycle ergometer in the early follicular phase (EF) and late follicular phase (LF), followed by 240 min of recovery from the ingestion of 200 mL of CHO or MILK every 30 min immediately after the exercise (POST0) until 210 min post-exercise. After 240 min, participants performed an exercise capacity test.

Educational considerations for health professionals to effectively work with clients with complex regional pain syndrome.

Introduction: People living with complex regional pain syndrome (CRPS), a rare chronic pain disorder, must become experts in their own self-management. Listening to the voice of the patient is often advocated in the pain literature. However, the patient's option is rarely asked for or considered by clinicians, even when they live with a condition that health professionals have rarely heard of.

Reactive arthritis incidence in a community cohort following a large waterborne campylobacteriosis outbreak in Havelock North, New Zealand.

Objectives: In August 2016, Campylobacter spp contaminated an untreated reticulated water supply resulting in a large-scale gastroenteritis outbreak affecting an estimated 8320 people. We aimed to determine the incidence of probable reactive arthritis (ReA) cases in individuals with culture-confirmed campylobacteriosis (CC), self-reported probable campylobacteriosis (PC) and those reporting no diarrhoea (ND).

Design: We conducted a retrospective cohort study to identify incidence of probable ReA cases.

Age- and sex-related differences of muscle cross-sectional area in iliocapsularis: a cross-sectional study.

Background: This study aimed to determine in how many individuals the iliocapsularis muscle (IC) could be identified on magnetic resonance imaging (MRI) and whether age and sex are associated with the cross-sectional area (CSA) of the IC.

Methods: Thirty-seven healthy younger adults and 40 healthy older adults were assigned to four groups: 1) 20 younger men; 2) 17 younger women; 3) 20 older men; and 4) 20 older women. The CSAs of the IC, IP, the rectus femoris (RF) and the quadriceps (QUAD) were quantified on an axial MRI.

Effect of different types of muscle activity on the gene and protein expression of ALDH family members in C57BL/6J mouse skeletal muscle.

Aldehyde dehydrogenase (ALDH) is an enzyme that detoxifies aldehydes and is primarily involved in alcohol metabolism. Recently, we have shown that ALDH also plays an important role in skeletal muscle homeostasis. To better understand the role of ALDH in skeletal muscle, it is necessary to clarify the adaptability of ALDH.

Properties of triceps surae and Achilles tendon in forefoot and non-forefoot strike runners.

Background: The purpose of this study was to compare the properties of the triceps surae and Achilles tendon of forefoot strike runners and non-forefoot strike runners.

Methods: Fourteen male college forefoot strike runners and 11 non-forefoot strike runners participated in this study. The shear elastic moduli and cross-sectional areas of the medial and lateral gastrocnemius, soleus, and Achilles tendon were measured.

Aldehyde dehydrogenase 2 deficiency promotes skeletal muscle atrophy in aged mice.

Aldehyde dehydrogenase 2 (ALDH2) detoxifies acetaldehyde produced from ethanol. A missense single nucleotide polymorphism (SNP) rs671 in exhibits a dominant-negative form of the ALDH2 protein. Nearly 40% of people in East Asia carry an inactive ALDH2*2 mutation.