scholarly journals Pedaling Performance Changing of Elite Cyclists Is Mainly Determined by the Fatigue of Hamstring and Vastus Muscles during Repeated Sprint Cycling Exercise

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Lejun Wang ◽  
Qineng Shao ◽  
Guoqiang Ma ◽  
Mingxin Gong ◽  
Wenxin Niu ◽  
...  
Keyword(s):  
Exercise Performance ◽  
Lower Limb ◽  
Muscle Group ◽  
Limb Muscle ◽  
Cycling Exercise ◽  
Lower Limb Muscles ◽  
Repeated Sprint ◽  
Grey Relational Grade ◽  
Sprint Cycling ◽  
Grey Relational

Repeated sprint cycling is an effective training method in promoting athletic performance of cyclists, which may induce severe fatigue of lower limb muscles. However, the relationship between the fatigue of each lower limb muscles and the changing of exercise performance remains unclear. In this study, ten cyclist volunteers performed a series of 6-second sprints with 24-s recovery for five times. Power, cadence, and EMG mean frequency (MNF) of each lower limb muscle group for every 2-second epoch, as well as the grey relational grade between exercise performance and MNF of each lower limb muscle group during the whole process were calculated. It has been found that MNF of Rectus femoris (RF), Vastus (VAS), Gastrocnemius (GAS), and the hamstring muscle group (HAM) showed significant negative correlation with the increase in both sprint number and intrasprint duration time, while the grey relational grade of HAM and VAS was higher than that of other muscles. The results demonstrated that the exercise performance of both power and cadence were most closing related to the fatigue degree of HAM and VAS during repeated sprint cycling exercise.

scholarly journals Grey Relational Analysis of Lower Limb Muscle Fatigue and Pedalling Performance Decline of Elite Athletes during a 30-Second All-Out Sprint Cycling Exercise

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lejun Wang ◽  
Hua Yang ◽  
Guoqiang Ma ◽  
Mingxin Gong ◽  
Wenxin Niu ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Exercise Performance ◽  
Lower Limb ◽  
Muscle Group ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Cycling Exercise ◽  
Performance Decline ◽  
Sprint Cycling ◽  
Grey Relational

The 30-second all-out sprint cycling exercise is a classical sport capacity evaluation method, which may cause severe lower limb muscle fatigue. However, the relationship between lower limb muscle fatigue and the decline in exercise performance during 30-second sprint cycling remains unclear. In this study, ten cyclists volunteered to participate in a 30-second all-out sprint cycling while power, cadence, and surface electromyographic (EMG) signals of eight lower limb muscles were recorded during the exercise. EMG mean frequency (MNF) of each lower limb muscle group was computed for every 3-second epoch based on wavelet packet transformation. Grey relational grades between pedalling performance and the EMG MNF of each lower limb muscle group during the whole process were calculated. The results demonstrated that EMG MNF of the rectus femoris (RF), vastus (VAS), gastrocnemius (GAS), and tibialis anterior (TA) progressively tired during a 30-second all-out sprint cycling exercise. Of the muscles evaluated, the degree of fatigue of TA showed the greatest association with exercise performance decline, whereas the muscle fatigue of RF, VAS, and GAS also significantly impacted exercise performance during a 30-second all-out sprint cycling exercise.

scholarly journals Strength capacity of lower-limb muscles in world-class cyclists: new insights into the limits of sprint cycling performance

2022 ◽  
pp. 1-18
Author(s):  
Iris Sachet ◽  
Niels Peter Brochner Nygaard ◽  
Gaël Guilhem ◽  
François Hug ◽  
Sylvain Dorel
Keyword(s):  
Lower Limb ◽  
Cycling Performance ◽  
Lower Limb Muscles ◽  
Strength Capacity ◽  
Limb Muscles ◽  
World Class ◽  
Sprint Cycling

scholarly journals Characteristics of Lower Limb Muscle Activity in Elderly Persons After Ergometric Exercise

2020 ◽  
Vol 6 ◽  
pp. 233372142097980
Author(s):  
Kenichi Kaneko ◽  
Hitoshi Makabe ◽  
Kazuyuki Mito ◽  
Kazuyoshi Sakamoto ◽  
Yoshiya Kawanori ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
The Elderly ◽  
Elderly Subjects ◽  
Elderly Persons ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Lower Limb Muscles ◽  
The Mean ◽  
Young Subjects

This study examined the characteristics of lower limb muscle activity in elderly persons after ergometric pedaling exercise for 1 month. To determine the effect of the exercise, surface electromyography (SEMG) of lower limb muscles was subjected to Daubechies-4 wavelet transformation, and mean wavelet coefficients were compared with the pre-exercise coefficients and the post-exercise coefficients in each wavelet level. The characteristics of muscle activity after pedaling exercise were also compared between the elderly subjects and young subjects. For the elderly subjects, the mean wavelet coefficients were significantly decreased in the tibialis anterior and the gastrocnemius medialis at wavelet levels of 3, 4, and 5 (125–62.5, 62.5–31.25, and 31.25–15.625 Hz, respectively), by pedaling exercise. However, the mean power of wavelet levels of 2 and 3 (250–125 and 125–62.5 Hz) within the rectus femoris and the biceps femoris were significantly increased in the young subjects. The effect of pedaling exercise is different from the effects of heavy-resistance training. It was suggested that the muscle coordination, motor unit (MU) firing frequency, and firing fiber type of lower limb muscles are changed with the different characteristics between elderly and young persons by pedaling exercise for 1 month.

scholarly journals Effects of Half-Time Cooling Using a Fan with Skin Wetting on Thermal Response During Intermittent Cycling Exercise in the Heat

2021 ◽  
Vol 05 (03) ◽  
pp. E91-E98
Author(s):  
Jumpei Osakabe ◽  
Masanobu Kajiki ◽  
Kiho Kondo ◽  
Takaaki Matsumoto ◽  
Yoshihisa Umemura
Keyword(s):  
Perceived Exertion ◽  
Thermal Sensation ◽  
Rating Of Perceived Exertion ◽  
Half Time ◽  
Physiological Strain ◽  
Cycling Exercise ◽  
Repeated Sprint ◽  
Significant Difference ◽  
Sprint Cycling ◽  
Experimental Trials

AbstractThe present study investigated the effects of half-time (HT) break cooling using a fan and damp sponge on physiological and perceptual responses during the 2nd half of a repeated-sprint exercise in a hot environment. Eight physically active men performed a familiarization trial and two experimental trials of a 2×30-min intermittent cycling exercise protocol with a 15-min HT break in hot conditions (35°C, 50% relative humidity). Two experimental trials were conducted in random order: skin wetting with a fan (FANwet) and no cooling (CON). During the 2nd half, a repeated-sprint cycling exercise was performed: i. e., 5 s of maximal pedaling (body weight×0.075 kp) every minute, separated by 25 s of unloaded pedaling (80 rpm) and 30 s of rest. Rectal temperature, skin temperature (chest, forearm, thigh, and calf), heart rate, physiological strain index, rating of perceived exertion, thermal sensation, and comfort were significantly improved in the FANwet condition (P<0.05). There was no significant difference in the repeated-sprint cycling exercise performance between conditions. The results suggest that skin wetting with a fan during the HT break is a practical and effective cooling strategy for mitigating physiological and perceptual strain during the 2nd half in hot conditions.

scholarly journals Interlimb neural interactions in corticospinal and spinal reflex circuits during preparation and execution of isometric elbow flexion

2020 ◽  
Vol 124 (3) ◽  
pp. 652-667
Author(s):  
Atsushi Sasaki ◽  
Naotsugu Kaneko ◽  
Yohei Masugi ◽  
Matija Milosevic ◽  
Kimitaka Nakazawa
Keyword(s):  
Lower Limb ◽  
Elbow Flexion ◽  
Motor Preparation ◽  
Lower Limbs ◽  
Spinal Reflex ◽  
Upper Limbs ◽  
Limb Muscle ◽  
Motor Execution ◽  
Lower Limb Muscles ◽  
Neural Interactions

We found that upper limb muscle contractions facilitated corticospinal circuits controlling lower limb muscles even during motor preparation, whereas motor execution of the task was required to facilitate spinal circuits. We also found that facilitation did not depend on whether contralateral or ipsilateral hands were contracted or if they were contracted bilaterally. Overall, these findings suggest that training of unaffected upper limbs may be useful to enhance facilitation of affected lower limbs in paraplegic individuals.

Effect of Garment Pressure on Lower Limb Muscle Activity during Running

2011 ◽  
Vol 175-176 ◽  
pp. 832-836 ◽  
Author(s):  
Ya Ning Li ◽  
A Ming Lu ◽  
Xiao Qun Dai ◽  
Jin Ao Chen ◽  
Xiao Wen Zhao
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Blood Circulation ◽  
Limb Muscle ◽  
Sports Performance ◽  
Healthy Male ◽  
Lower Limb Muscles ◽  
Male College ◽  
Limb Muscles ◽  
The Right

Recently, it has been reported that suitable garment pressure contributes to accelerating human blood circulation, improving sports performance and alleviating sports fatigue. In this study, effect of pressure exerted by knee-high gradient compression socks (GCS) on the lower limb muscles was investigated. Two healthy male college students volunteered to participate in this study. They were asked to run on a treadmill at a speed of 10 km/h with a GCS worn on one leg and a usual sports sock worn on the other leg until being tired out. During running, the surface electromyography (sEMG) of two lower limb muscles —— gastrocnemius medialis of the right leg (R-GM) and the left leg (L-GM) was recorded simultaneously. It was found that: pressure exerted on the lower limb by GCS gradually decreased from ankle to below-knee; GCS pressure helped to reduce muscle oscillation; wearing GCS seemed to help to reduce muscle fatigue during running.

VYZVANNAYa BIOELEKTRIChESKAYa AKTIVNOST' MYShTs NIZhNIKh KONEChNOSTEYU BOL'NYKh GONARTROZOM

2003 ◽  
Vol 10 (1) ◽  
pp. 63-66
Author(s):  
A P Shein ◽  
T V Sizova ◽  
N K Chikorina ◽  
V D Makushin ◽  
O K Chegurov
Keyword(s):  
Great Degree ◽  
Lower Limb ◽  
Comparative Evaluation ◽  
Surgical Intervention ◽  
Bioelectrical Activity ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Lower Limb Muscles ◽  
Limb Muscles

Comparative evaluation of functional lower limb muscle status depending on gonarthrosis severity and technique of surgical intervention was performed using the results of stimulation electromyography (M-responses). Data obtained showed that the changes of evoked bioelectrical activity in lower limb muscles depend to a great degree on the initial status (gonarthrosis grade) than on the technique of surgical intervention.

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