Study On Kayak Sprint Specific Core Instability Training

Objective: This research bring up the conception of “Kayak Specific Core Instability Training” based on the analysis of dynamics character of Kayak( Still Water) and technique feature. Meanwhile, aiming at the current situation of lacking special core instability training instrument, designed and product “one-axis kayak ergometer”, and conducted an experiment research to testify its effectiveness. Discussing the impaction on paddle movement and muscle working situation by improving stroke frequency and adding unstable factor which simulating on-water condition, as well as the impaction on muscle working situation and paddle performance by adding special core instability training to Kayak training. This research may provide theory and practice reference for completing Kayaking specific training system, improving training efficiency and improving kayak athletes competitive ability targetly.Methods:1) With considering the character of Kayak movement and training needs, this research designed and product “one-axis kayak ergometer” increased the activity freedom of frontal plane which take the vertical axis as the axle center, and more similar to the on-water kayaking mechanics conditions.2) Using 23 professional kayak athletes above level 1(including level 1) as subjects, conducted consistent paddle movement on ergometer and one-axis ergometer under three various stroke frequency intensity(70spm 、 90 spm 、 max), by collecting and analyzing Surface Electromyography(s EMG), Saturation of Muscle Oxygen(Sm O2)of related muscles, paddle power, velocity, distance, and heart rate(HR), blood lactate(Bla), max stroke frequency, acquire the acknowledgment of effect on paddle movement and muscle working situation by various stroke frequency and adding unstable factor which simulating on-water condition. 3) Specific core instability training intervention. Based on the characteristics of Kayak technical and working pattern of major muscle groups, give out a 8-weeks specific core instability training suggestion for Hebei Kayak team. 4) Using 14 professional kayak athletes above level 1(including level 1) as subjects, conducted consistent paddle movement on ergometer and one-axis ergometer under three various stroke frequency intensity(70spm、90spm、max) after 8-weeks specific core instability training, compare s EMG, Sm O2 of related muscles, paddle power, velocity, distance, and HR, Bla, max stroke frequency dates before and after training, combined with on-water paddle performance, illustrated the effect of adding specific core instability training on Kayak technique and performance.Results: 1) Paddle on stable ergometer, with stroke rate raises, the electricity activity of Erector Spinae(ES) increased, meanwhile the electricity activity of Rectus Femoris(RF) decreased; compare with 70 spm, under maximum stroke race, Triceps Brachii(TB) decreased but not reach a significant level, both side of Latissimus Dorsi(LD) decreased significantly(p<0.05); paddle power velocity increase significantly, paddle power and velocity obviously enhanced, but paddle distance under max stroke rate show great lost, which suggested a deficient of pulling. 2) Paddle on one-axis kayak ergometer, the electricity activity show no obvious difference between 70 spm and 90 spm, significant various appeared under maximum stroke frequency, the electricity activity of ES significantly enhanced and the electricity activity of RF decreased. At the same tine,Sm O2 of both side TB increased while Sm O2 of LD decreased. The value of dynamics index appears poor symmetry. While paddle under 70 spm and 90 spm, power value differs between left and right side very significantly(p<0.01), velocity value of 70 spm differs between left and right side very significantly(p<0.01), under 70 spm and 90 spm distance value differs between left and right side significantly(p<0.05).3) Paddle on one-axis ergometer with low stroke rate, integrated EMG(i EMG) of RF decreased(p<0.05), average EMG(MA) of left RF decreased(p<0.05), Root Mean Square(RMS) of left RF and left ES also decreased(p<0.05); under 90 spm, i EMG and RMS of ES increased significantly(p<0.05), and maximum stroke rate, both side of ES’s i EMG、MA and RMS decreased significantly(p<0.05), while right ES’s i EMG, both ES’s MA and right ES’s RMS rised(p<0.05), only left ES’s RMS decreased(p<0.05).The paddle movement on one-axis kayak ergometer under maximum stroke rate show good symmetry. Left TB’s Sm O2 with maximum stroke rate and right TB with all three kinds of stroke rate show obvious raise(p<0.05); while left LD with 90 spm and right LD with all three stroke rates show obvious decrease(p<0.05).The maximum stroke rate could be achieved various significantly between two type of ergometer-lower on one-axis kayak ergometer, while HR and Bla under maximum stroke rate insignificantly different. 4) After 8-weeks special core instability training intervention, when paddle on one-axis kayak ergometer, s EMG, Sm O2 and dynamics index value show a tendency of symmetry. Both side of RF’s i EMG significantly decreased(p<0.05), both ES’s i EMG significantly enhanced(p<0.05).Under 70 spm, both side TB’s Sm O2 obviously decreased(p<0.05), right LD decreased very significantly(p<0.01); under 90 spm,both side TB decreased very significantly(p<0.01); with maximum stroke rate, left TB extremely decreased(p<0.001), right TB and left LD very significantly decreased(p<0.01), right LD significantly decreased(p<0.05). Both side paddle power on one-axis ergometer significantly enhanced(p<0.05), left paddle velocity with 70 spm obviously enhanced(p<0.05). Major different appears at maximum stroke rate, both types of ergometer paddling show very significantly raise in power and velocity(p<0.01), both side of stroke distance on stable ergometer show very significant raise(p<0.01), and extremely significant raise on one-axis ergometer(p<0.001). Compare with pretraining, paddle with 90 spm on one-axis ergometer, the Bla value raised significantly(p<0.05), with maximum stroke rate paddling on both ergometer, the blood lactate value raised very significantly(p<0.01). After training,the maximum heart rate could be achieved rising on both type of ergometer, among which one-axis kayak ergometer reach the significant level(p<0.05).Conclusions: 1) Stroke rate increasing lead to alternate of body power application structure, with stroke rate increasing, the contribute of lower body decreased, paddle movement is more reliance on trunk, the LD motion unit recruitment increased. Paddle on one-axis ergometer produce stronger stimulation to core muscle groups, paddlers need seek for balance actively, but the unstable support lead to weaker paddle power and lower maximum stroke rate.2) Kayak special core instability training enhance the capacity of maintain balance by trunk, which create stable condition for power force of movement, and allow athletes increase their muscle force during paddle movement on a instable plane, and enhance symmetry of power force from both side of body efficiently. 3) 8-weeks specific core instability training produced a positive effect on kayak performance. 4) Compared with stable kayak ergometer, one axis ergometer is more match on-water dynamic condition; it can be used as a specific core instability training instrument during daily training and testing.