| Background: Fencing was a unique sport, and this was reflected in the unusual patterns of musculoskeletal development possessed by fencers. It was one of the few sports in which the lower, as well as the upper, body becomed grossly asymmetrical in muscular development. Though three weapons were used in fencing, footwork actions were similar in combat. The physical demands of fencing competition were high; aerobic and anaerobic energy mechanisms might be specified in fencers for difference in rules, techanic and tactis models. Studies on above were very scarce or even non-existent.Objective: The purpose of this study was to investigate the iskinetics strength, metabolic characteristics in competition, difference in aerbic and anaerobic capacity between weapons and monitor performance and functional status before important competition. Furthermore, the results of these evaluations were used to adjust training in an attempt to keep fencers at good condition, and provid theoretical support for training practice. Subjects: The subjects for this study consisted of 26 members of the 2008 China Olympic fencing squad. Each of the three fencing weapons was respensted; 4 men and 5 women used epee, 5 men and 4 women foil, 4 men and 4 women sabre. All subjects were international ranks, 20 of whom obtained the qualification for 2008 Olymipcs late.Methods:To test muscle forces, an IsoMed 2000 iskinetic dynamometry was used to assess the muscle performance. Bilateral legs'flexors and extensors concentric peak torques were measured including hips, knees and ankles at 60o/s and 240o/s; flexor and extensor PT of domiant upper limb's shoulder was tested at 60o/s and 180o/s; elbow and wrist adduction/audition at 60o/s and 240o/s, tunk was accessed at 60o/s. Muscle strength tests were performed twice separately before and after training stage.To estimate anaerobic and aerobic capacity, maximal oxygen uptake was tested on treadmill and 30s Wingate test was conductd thrice respectively before training, during training session, and after training stage.During national fencing competition, heart rate, blood lactate concentrations assessed during direct elimination bouts and finals; the levels of creatine kinase and blood urea were tested at rest, immediately and the morning after competition. To monitor functional status of fencers in pre-competition period, hemoglobin, serum creatine kinase and blood urea were tested every Monday monring on empty-stomach state; serum testosterone and plasma cortisol concentrations were assessed thrice before camp, in training period and after training stage respectively.Results:1. Isokinetic strengthLower extremity: dynamic forces in fencers trail and leading leg showed a typical asymmetry, especially in men. Bilateral leg muscle forces of hip flexors and extensors were significantly different (p<0.05), extensor strength were significantly greater than flexors in both legs, forces of hip extensor differed more obviously at fast speed (p<0.05); Bilateral knee flexors strength was different significantly in men (p<0.05), more significant differences in extensors (p<0.05), knee extensor still significant different (p<0.05) under fast speed; ankle flexion and extension forces in leading leg was greater than in trialing leg (p<0.05). Muscle strength characteristics in three joints of lower extremities in fencers were not weapon-dependent (p>0.05);Trunk and dominant upper extremity: dominant shoulder extensor force increased more than flexor at fast speed, extensor was more suitable for concentric contract, F/E ratio in normal range; flexor forces were significantly lower than extensor in dominant elbow at slow and fast test, extensor more suitable for fast contract; wrist abductor strength was overall less than auditor muscles at sword-holding postion, epee fencers'adductors were significantly high than in the foil at slow speed (p <0.05), while auditor of men's foil fencers was significantly higher than men's epee at fast speed (p <0.05), foil's adductor/auditor ratio was significantly higher than epee at fast speed (p <0.05); trunk extensor strength in fencers was strong and flexor was weak.2. Metabolic characteristic and pre-competition performanceDuiring national fenceing competition, blood lactate concentration (BLA) in semi-finals and finals were significantly higher than the other bouts (p<0.05); BLA in 1/16 qualification bouts were near semi-finals and finals (p>0.05); BLA of quarter-finals, in the lowest, differed significantly with semi-finals and finals (p<0.05). Heart rate in 90%-100%HRmax in combat were epee, foil and saber in men; and foil, epee and foil in women (p<0.05) from high to low. Blood creatine kinase and BU after competition were significantly higher than that at rest (p<0.01), and did not return to rest levels 12 hours after competition (p<0.01).Maximal oxygen uptake of foil was the highest, while women sabre the lowest (p<0.05); WAnT peak power of men's sabre fencers was significantly higher than foil and epee (p<0.05); average power of men's foil and sabre were significantly higher than men's epee group (p<0.05); power decrease were sabre, epee and foil fencers in man (p<0.05). There was no significant difference in peak power between women groups, average power of women's foil was significantly higher than the other groups (p<0.05), the highest power decrease was sabre fencers in female groups (p<0.05).3. Monitor functional status in pre-competition trainingIn addition, men's epee had lower maximal oxygen uptake before competition, the other groups were significantly higher than basic value (p<0.05); peak power and average power in each groups before competition were significantly higher than basic value (p<0.05); trunk flexor peaks torque at 60°/s trended to be increase, but had no significant difference (p>0.05), trunk extensor increased significantly (p<0.05);At sword-holding position under 60°/s wrist adductor peak torque increased significantly for men and women fencers (p<0.05), wrist auditor peak torque increased significantly in men fencers (p<0.05), wrist adductor/auditor ratio increased significantly in women fencers (p<0.01); at 240°/s men fencers wrist adductor and auditor peak torque increased significantly (p<0.05), only a significant increase in adductor muscle PT in women fencers (p<0.05), wrist adductor/auditor PT ratio ratio increased significantly for both men and women (p<0.05); fencers bilateral ankle, knee flexor and extensor at 60°/s, 240°/s increased in both leg, however, no significant difference.Throughout the training stage Hb showed going up following by falling. Among them, Hb of men's foil, men's eppe at the 2nd and 3rd weeks reached the lowest levels in this stage (p<0.05), Hb of women's foil and epee showed significant drop after the 1st week (p<0.05), women's epee'Hb in the subsequent two and three weeks remained unchanged, and returned to the pre-training level two weeks before the Olympics; women'foil'Hb rised in the second week followed by no significant changes.The overall changes of CK in fencers trended to drop after increase. CK increased significantly after the 1st week of training, in the training of second and thrid 3 weeks reached peak value respectively, and still did not return to the level before training at the fourth week. Two weeks before the competition in men's epee and women's foil groups, CK still significantly higher than pre-training levels (p<0.05); men'BU reached peak value at the second and third weeks, BU of men's foil returned to pre-training level in the fourth week (p<0.05); men's epee shown markable increase in BU at the fourth week and two weeks before competition (p<0.05); BU reached the peak at the 2nd and 3rd weeks of training, there was no significant difference (p>0.05) at the fourth week and two weeks before competition; BU of women's epee elevated in the training stage but no significant difference between each stages (p>0.05), two weeks before competition their BU reached the highest level (p<0.05).Basic value of men'testosterone in epee was significantly higher than the others, foil fencers'was the highest in women groups (p<0.05); for cortisol test results, there was no significant difference (p>0.05) between male groups. There was no significant difference (p>0.05) in testosterone of men's epee fencers for 3 tests, testosterone trended to increase in men's foil before competition, no significant difference was found in 3 times (p>0.05); epee, foil fencers testosterone level before training and two weeks before competition in female was significantly higher than the basic level (p<0.05); the level of cortisol before training was significantly higher than the basic value, men'epee and foil fencers'level two weeks before competition were not significant change compared with basic value; cortisol in female, significant higher cortisol level were found 2 weeks before competition when compared with the basic (p<0.05).Conclusions:1. The bilateral lower limbs in isokinetic forces of fencers were asymmetries, the specificites of strength was closely related to fencing step actions; muscle strength in the dominant upper limb's shoulder, elbows were interrelated with fencing touch; there were siginficant difference in wrist strength of adductor and auditor under sword-holding position between fencers used different weapons. The weak muscles of elite fencers were hip extensor, hamstring muscles, ankle extensor and trunk flexor.2. Fencing was a typical anaerobic energy supply events, as glycolysis for the main energy pathway in fencing. The specificity of metabolic supply was different between weapons in ATP-CP system, glycolysis system; the requirements in aerobic and anaerobic capacity were different between weapons.3. Specific physical training significantly improved aerobic and anaerobic capacity, trunk muscle strength in flexors and extensors, wrist adductor and auditors improved significantly; in the training period, Hb, CK and BU changed dramatically, CK was sensitive to intensity, Hb, BU sensitive to load; two weeks before 2008 Olympics, fencers'T was at high level, and C had increased, work loads was properly under coaches'control.
|
PDF Full Text Request