the effects of knee extensor and flexor strength and

௅th$QQLYHUVDU\௅

THE EFFECTS OF KNEE EXTENSOR AND FLEXOR STRENGTH AND ASYMMETRY ON SPRINT CYCLING PERFORMANCE OF COMPETITIVE ROAD CYCLISTS ,QGUHN5DQQDPD.LUVWL3HGDN.ULVWMDQ3RUW School of Natural Sciences and Health, Tallinn University, Estonia

7KHSXUSRVHRIWKLVVWXG\ZDVWRFKDUDFWHULVHELODWHUDOVWUHQJWKDV\PPHWU\RINQHHH[WHQVRUDQGÀH[RUPXVFOHV among competitive level road cyclists as well as examine the effect of muscle strength, pedalling technique and bilateral DV\PPHWU\RIWKRVHSDUDPHWHUVGXULQJWKHVHFRQGVHDWHGIDWLJXLQJF\FOLQJVSULQWSHUIRUPDQFH7KHF\FOHVSULQW H[HUFLVHZDVSHUIRUPHGRQ&\FOXVHUJRPHWHULQVHDWHGSRVLWLRQDQGDYHUDJHUHODWLYHSRZHU:NJ ELODWHUDOSHGDOOLQJ SRZHUFRQWULEXWLRQDQGSHGDOOLQJVPRRWKQHVV36 ZHUHFDSWXUHG7KHLVRNLQHWLFVWUHQJWKRINQHHH[WHQVRUV(; DQG ÀH[RUV)/ ZHUHPHDVXUHGRQDQGƒVWHVWLQJVSHHGDQGH[SUHVVHGDVUHODWLYH1PNJ 3HDN7RUTXH37 DQG $YHUDJH7RUTXH$Y7 RIUHSHWLWLRQV7KHUHVXOWVRIWKHFXUUHQWVWXG\GHPRQVWUDWHWKDWGXULQJWKHVHFRQGPD[LPDO F\FOLQJVSULQWWKHVWURQJHVWSUHGLFWRURISHUIRUPDQFHZDVNQHHH[WHQVRUV¶DELOLW\WRJHQHUDWHKLJKDYHUDJHWRUTXHGXULQJ 20 repetitions. However, at higher cycling power there was evident reduction in the smoothness of pedalling witch may KDYHDSRWHQWLDOO\GHWULPHQWDOHIIHFWDQGWKDWZDVDOVRUHÀHFWHGLQWKHELODWHUDODV\PPHWU\RINQHHÀH[RUVVWUHQJWKDQG strength endurance performance among the test subjects. Key words:&\FOXV3HDN7RUTXH,VRNLQHWLF3HGDOOLQJVPRRWKQHVV

Introduction 5RDGF\FOLQJLVDVSRUWZKHUHWKHF\FOLVWVSHQGVPRVWRIRQH¶VWUDLQLQJDQGFRPSHWLWLRQWLPHRQORZLQWHQVLW\OHYHO EXWWKHVXFFHVVLQPDVVVWDUWUDFHVLVKLJKO\UHODWHGWRF\FOLVW¶VDELOLW\WRSURGXFHKLJKSRZHULQVKRUWWLPH-HXNHQGUXS HWDO 'XULQJVXEPD[LPDOF\FOLQJWKHGRPLQDWLQJPXVFOHVLQSHGDOOLQJSRZHUSURGXFWLRQDUHNQHHH[WHQVRUVZLWK UHODWLYHFRQWULEXWLRQXSWR%URNHUDQG*UHJRU EXWGXULQJPD[LPDOF\FOLQJWKHPRVWGRPLQDWLQJPXVFOHJURXS LVKLSH[WHQVRUV:KDWLVPRUHWKHUHLVDQLQFUHDVHLQWKHNQHHÀH[RUV¶FRQWULEXWLRQWRWKHSRZHUSURGXFWLRQ(OPHUHWDO 0DUWLQDQG%URZQ ,WLVIRXQGWKDWXSWRVHFRQGVHDWHGVSULQWF\FOLQJSRZHULVVWURQJO\FRUUHODWHGZLWK KLSH[WHQVRUVDQGPRGHUDWHO\ZLWKNQHHH[WHQVRUVDQGÀH[RUVLVRNLQHWLFVWUHQJWKLQFRPSHWLWLYHURDGF\FOLVW¶VSRSXODWLRQ 5DQQDPDHWDO ,QQRQF\FOLVWV¶SRSXODWLRQWKHPHDQVHFRQG:LQJDWHF\FOLQJWHVWSRZHUFRUUHODWHGVWURQJO\ ZLWKNQHHÀH[RUVDQGH[WHQVRUVLVRNLQHWLFSHDNWRUTXHDWƕVDQGPRGHUDWHO\ZLWKKLSÀH[RUVDQGH[WHQVRUVDWWKH VDPHVSHHG6PLWK 7KHUHLVVRPHHYLGHQFHWKDWQRWRQO\WKHVWUHQJWKDELOLW\RIORZHUOLPEV¶PXVFOHVEXWDOVR the bilateral symmetry in leg muscles strength is an important factor of higher performance in multi joint closed kinetic FKDLQH[HUFLVHVVXFKDYHUWLFDOMXPS%DLOH\HWDO DQGPD[LPXPVHFRQGF\FOLQJSRZHU5DQQDPDHWDO  The existence of bilateral asymmetry in cycling pedalling technique and lower limbs muscle activation is quite well GRFXPHQWHG&DUSHVHWDO(GHOLQHHWDO6PDNHWDO EXWWKHUHLVOLPLWHGHYLGHQFHDERXWDV\PPHWU\ OHYHOVRINQHHH[WHQVRUVDQGÀH[RUVDVPRVWORDGHGPXVFOHJURXSVLQF\FOLQJ0RUHRYHUWKHUHLVDODFNRIHYLGHQFHKRZ the symmetry level or existence of asymmetry in the mentioned muscle groups is related to performance during maximal fatiguing sprint cycling exercise. At the moment the literature published on the relationships between various asymmetries and cycling performance is rather limited and inconsistent. 7KHSXUSRVHRIWKLVVWXG\ZDVWRFKDUDFWHULVHELODWHUDOVWUHQJWKV\PPHWU\RINQHHH[WHQVRUDQGÀH[RUPXVFOHVDPRQJ competitive level road cyclists and examine the effect of muscle strength, pedalling technique and bilateral symmetry of WKRVHSDUDPHWHUVGXULQJWKHVHFRQGVHDWHGIDWLJXLQJF\FOLQJVSULQWSHUIRUPDQFH

Methods 3DUWLFLSDQWVRIWKHFXUUHQWVWXG\LQFOXGHGFRPSHWLWLYHMXQLRUQ  DQG8Q  FODVVPDOHURDGF\FOLVWV“ \HDUV“FP“NJ $OODWKOHWHVSDUWLFLSDWLQJKDGKDGDWOHDVW\HDUVRIIRFXVHGHQGXUDQFHF\FOLQJWUDLQLQJ and competition experience, and had annual cycling distance above 12000 km during the last season. The participants were free of injuries and the study was conducted during the preparation period of cycling season.



Kinesiology of Top-level Sport

Abstract

Kinesiology of Top-level Sport

8th International Scientific Conference on Kinesiology, 2017, Opatija, Croatia

All H[SHULPHQWDOSURFHGXUHV for one person were made on the same day. The experimental cycling exercise was SHUIRUPHGRQWKH&\FOXVF\FOLQJHUJRPHWHU$YDQWURQLF&\FOXV/HLS]LJ*HUPDQ\ XVLQJWKHDWKOHWH¶VSHUVRQDO UDFLQJELNH$IWHUDPLQXWHZDUPXSWKHF\FOLVWVSHUIRUPHGDVHFPD[LPDOF\FOLQJWHVWLQLVRNLQHWLFPRGHZLWKWKH target cadence 100 rpm in seated cycling position hands on the drops. The average power of 30 seconds was normalized ZLWKF\FOLVW¶VERG\PDVVDQGZDVLQFOXGHGLQWKHIXWXUHDQDO\VHVDVSHUIRUPDQFHPHDVXUH,QRUGHUWRPHDVXUHWKH SHGDOOLQJNLQHWLFVDQGEHWZHHQOHJVELODWHUDOGLIIHUHQFHVLQSHGDOOLQJSRZHUDQGWHFKQLTXHHDFKSDUWLFLSDQW¶VELF\FOH ZDVHTXLSSHGZLWKDSDLURI*DUPLQ9HFWRUSRZHUPHWHUSHGDOV*DUPLQ9HFWRUŒ 7KHVDPH9HFWRUSHGDOVZHUHXVHG WKURXJKRXWWHVWLQJDQGZHUHFDOLEUDWHGEHIRUHHDFKWHVWLQJVHVVLRQDFFRUGLQJWRWKHPDQXIDFWXUHU¶VJXLGHOLQHV7KHSHGDOOLQJ WHFKQLTXHZDVGHVFULEHGE\WKHVHFRQGVDYHUDJHSHGDOOLQJVPRRWKQHVV36 32:DYJ32:PD[  FROOHFWHG IURP*DUPLQ9HFWRUSHGDOVZLWKVHFRQGLQWHUYDOVLQGHSHQGHQWO\IRUWKHOHIWDQGULJKWVLGHWKURXJKRXWWKHH[SHULPHQWDO H[HUFLVH)XUWKHUPRUHWKHDEVROXWHEHWZHHQOHJVELODWHUDOV\PPHWU\LQGH[$6,  _5LJKW/HIW_ 5LJKW/HIW  was calculated for POW and PS. $IWHUWKHF\FOLQJH[HUFLVHDPLQXWHDFWLYHDQGPLQXWHSDVVLYHUHFRYHU\WLPHZDVDOORZHGEHIRUHWKHVWUHQJWKWHVW VWDUWHG$+80$&1250&RPSXWHU6SRUWV0HGLFLQH,QF6WRXJKWRQ0$86$ LVRNLQHWLFG\QDPRPHWHUZDVXVHG WRDVVHVVNQHHH[WHQVRUV(; DQGÀH[RUV)/ VWUHQJWKLQLVRNLQHWLFPRGHDQGLQVHDWHGSRVLWLRQ$OOWHVWSURFHGXUHVDQG G\QDPRPHWHUVHWWLQJVZHUHFDUULHGRXWLQDFFRUGDQFHZLWKWKH+80$&1250XVHUPDQXDODQGWKH³JUDYLW\FRUUHFWLRQ´ features were used in all tests to avoid gravity effect of limb weight. All tests were performed concentrically and velocities ƒVPD[LPXPVWUHQJWK DQGƒVVSHHGVWUHQJWKDQGVWUHQJWKHQGXUDQFH ZHUHXVHG$WHDFKWHVWYHORFLW\WKHVXEMHFW SHUIRUPHGVXEPD[LPDOZDUPXSWULDOVIROORZHGE\ƒV RUƒV PD[LPDOWHVWWULDOVDIWHUDVHFRQGUHFRYHU\ ,QWHVWLQJVSHHGRIƒVWKHVXEMHFWZDVLQVWUXFWHGWRVWDUWDVIDVWDVSRVVLEOHWRPHDVXUHWKHSHDNWRUTXHYDOXHWRR A recovery period of 2 minutes between test velocities and at least 5 minutes between body sides was used and testing RUGHURIERG\VLGHVZDVUDQGRPLVHG7KHSHDNWRUTXH37 RIWKHEHVWWULDOLQDQGƒVWHVWLQJVSHHGZHUHFDSWXUHG DVPD[LPXPVWUHQJWKYDULDEOHVDQGDYHUDJHWRUTXH$Y7 RIUHSHWLWLRQVFDSWXUHGEHWZHHQDQGGHJUHHNQHH ÀH[LRQDQJOHWRDYRLGQRLVRNLQHWLFYDOXHVLVIXOO\H[WHQGHGNQHHSRVLWLRQ ZDVWDNHQDVPHDVXUHRIVWUHQJWKHQGXUDQFH YDULDEOH)RUWKHIXWXUHDQDO\VHVDOOVWUHQJWKYDOXHVZHUHQRUPDOL]HGZLWKWKHERG\PDVV1PNJ DQGWKHPHDQYDOXHV RIULJKWDQGOHIWOHJZHUHXVHGLQVWDWLVWLFDOSURFHGXUHV0RUHRYHUWKHELODWHUDOWKLJKPXVFOHV$6,V ZHUHFDOFXODWHG according to the formula presented above. Data analysisZDVSHUIRUPHGE\XVLQJWKH,%063666WDWLVWLFVYHUVLRQIRU:LQGRZV$OOWKHGDWDZHUHWHVWHGIRU WKHLUQRUPDOGLVWULEXWLRQ.ROPRJRURY6PLUQRYWHVW GHVFULSWLYHVWDWLVWLFVZHUHFRPSXWHGIRUDOOYDULDEOHVDQGH[SUHVVHG DVDPHDQ“6'7KHWZRWDLOHG7WHVWIRUSDLUHGVDPSOHVZDVH[SORLWHGWRFRPSDUH$6,VRIGLIIHUHQWPXVFOHJURXSVDQG pedalling kinetics variables. The Pearson correlations analysis was performed to determine the relationships between VSULQWF\FOLQJSHUIRUPDQFHWHVWDQGLVRNLQHWLFVWUHQJWKWHVWVYDULDEOHV6LJQL¿FDQFHOHYHOIRUDOOWHVWVZDVVHWDWS7R H[DPLQHWKHUHODWLRQVKLSVEHWZHHQF\FOLQJSRZHUGHSHQGHQWYDULDEOH DQGSHGDOOLQJVPRRWKQHVVWKLJKPXVFOHVVWUHQJWK DQGVWUHQJWKDQGSHGDOOLQJV\PPHWU\YDULDEOHVLQGHSHQGHQWYDULDEOHV WKHVWHSZLVHPXOWLSOHOLQHDUUHJUHVVLRQVZHUH SHUIRUPHG7KHHQWU\VLJQL¿FDQFHOHYHOIRULQGHSHQGHQWYDULDEOHVZDVSZKLOHWKHUHPRYDOVLJQL¿FDQFHOHYHOZDV VHWDWOHYHOS!

Results and discussion The descriptive statistics of cycle sprint power and pedalling technique and symmetry is presented in Table 1 and WKHUHVXOWVRILVRNLQHWLFVWUHQJWKWHVWVDUHSUHVHQWHGLQ7DEOH7KH3HGDOOLQJ6PRRWKQHVV$6,ZDVVLJQL¿FDQWO\S  KLJKHUWKDQ3RZHU$6,DQG.QHH(;$6,LQDOOWHVWLQJFRQGLWLRQV.QHH)/$6,ZDVVLJQL¿FDQWO\KLJKHUWKDQ.QHH(; $6,LQDYHUDJHWRUTXHYDOXHVRIUHSHWLWLRQVDWWHVWLQJVSHHGRIƒV7KHPXVFOH$6,UHVXOWVDUHVLPLODUWRSUHYLRXVO\ GHVFULEHGWUDLQHGORQJGLVWDQFHUXQQHUV¶SRSXODWLRQLQZKLFKWKHNQHHÀH[RUVDV\PPHWU\ZDVDOVRWKHODUJHVWDWKLJK WHVWLQJVSHHG'HOODJUDQDHWDO  7DEOH7KHGHVFULSWLYHVWDWLVWLFVRIVHFRQGVSULQWF\FOLQJSHUIRUPDQFHDQGSHGDOOLQJWHFKQLTXHSDUDPHWHUV N= 36

Minimum

Maximum

Mean

SD

30 sec absolute Power (W)

567.3

1043.3

769.4

100.8

30 sec relative Power (W/kg)

9.04

12.25

10.42

0.84

Pedalling Smoothness (%)

27.9

40.0

32.8

2.8

Power ASI (%)

0.0

15.7

3.8

3.5

Pedalling Smoothness ASI (%)

3.0

15.2

8.7*

3.6

*-Significantly different from Power ASI



௅th$QQLYHUVDU\௅ 7DEOH'HVFULSWLYHVWDWLVWLFVRIWKLJKPXVFOHVLVRNLQHWLFVWUHQJWKFKDUDFWHULVWLFV Strength (Nm/kg)

ASI (%)

N=36 Knee Flexors Parameter Peak Torque

Knee Extensors

Knee Flexors

Knee Extensors

Velocity

Mean

SD

Mean

SD

Mean

SD

Mean

SD

60 ƒ/s

1.89

0.25

3.06

0.41

5.9

4.9

6.1

5.3

Peak Torque

180 ƒ/s

1.37

0.16

2.13

0.21

7.1

5.8

5.4

3.1

Average torque of 20 rep

180 ƒ/s

0.95

0.13

1.65

0.18

7.9

5.9

5.2*

4.2

*-Significantly different from Knee Flexors AvT ASI

7DEOH5HODWLRQVKLSVEHWZHHQVHFRQGF\FOLQJSRZHUSHGDOOLQJWHFKQLTXHDQGLVRNLQHWLFVWUHQJWKYDULDEOHV 1 -.388*

1

Knee Flexsors PT at 60 ƒ/s

.411

-.072

1

Knee Extensors PT at 60 ƒ/s

.498**

-.034

.730**

Knee Flexsors PT at 180 ƒ/s

.485

**

-.308

.760

**

.523**

1

Knee Extensors PT at 180 ƒ/s

.687**

-.312

.639**

.792 **

.635**

Knee Flexsors AvT at 180 ƒ/s

.477

**

-.131

.698

**

*

.404

.847

**

.576**

1

Knee Extensors AvT at 180 ƒ/s

.747**

-.227

.580**

.688**

.589**

.924**

.593**

*

1

1

1

*. Correlation is significant at the 0.05 level (2-tailed). **. Correlation is significant at the 0.01 level (2-tailed).

7KHUHODWLYHVHFRQGDYHUDJHVSULQWF\FOLQJSRZHULVVLJQL¿FDQWO\DQGSRVLWLYHO\7DEOH FRUUHODWHGZLWKWKLJK muscles isokinetic strength variables, but the strongest correlations are with Knee EX strength and strength endurance PHDVXUHGDWWHVWLQJVSHHGƒVZKLFKLVFRPSDUDEOHWRSUHYLRXV¿QGLQJV5DQQDPDHWDO6PLWK 7KH UHODWLRQVKLSVEHWZHHQNQHH)/VWUHQJWKDQGF\FOLQJSRZHUDUHRQPRGHUDWHOHYHO7KHKLJKHUF\FOLQJSRZHUSURGXFWLRQLV DOVRPRGHUDWHO\DVVRFLDWHGZLWKOHVVVPRRWKHUSHGDOOLQJSRZHUSURGXFWLRQDQGLVLQOLQHZLWKSUHYLRXV¿QGLQJVLQGLFDWLQJ WKDWVWURQJHUF\FOLVWWHQGVWRSURGXFHSRZHUPRUHLPSXOVLYHO\GXULQJSXVKLQJSKDVH&R\OHHWDO  7DEOH5HODWLRQVKLSVEHWZHHQVHFRQGF\FOLQJSRZHUDQGDV\PPHWULHVLQSHGDOOLQJWHFKQLTXHDQGLVRNLQHWLFVWUHQJWKYDULDEOHV Power (W/kg)

1

Power ASI (%)

.200

1

Pedalling Smoothness ASI (%)

.273

.353*

1

Knee Flexsors PT ASI at 60 ƒ/s

-.198

-.070

.356*

1

Knee Extensors PT ASI at 60 ƒ/s

.077

.271

.021

.243 *

.172

1

.197

.146

Knee Flexsors PT ASI at 180 ƒ/s

-.364

-.113

.212

.405

Knee Extensors PT ASI at 180 ƒ/s

.095

-.262

-.205

.202

Knee Flexsors AvT ASI at 180 ƒ/s Knee Extensors AvT ASI at 180 ƒ/s

*

-.357

*

-.030

1

1

-.079

.007

.236

.053

.310

.213

1

.108

-.026

-.006

-.065

.186

.532 **

.252

1

*. Correlation is significant at the 0.05 level (2-tailed). **. Correlation is significant at the 0.01 level (2-tailed).

7DEOHGHPRQVWUDWHVWKDWOHVVV\PPHWULFDO.QHH)/VWUHQJWKDQGVWUHQJWKHQGXUDQFHYDOXHVLQKLJKHUWHVWLQJVSHHG DUHVLJQL¿FDQWO\U DQG UHODWHGWRORZHUF\FOLQJSHUIRUPDQFH)XUWKHUPRUHWKHSHGDOOLQJVPRRWKQHVV$6, LVPRGHUDWHO\SRVLWLYHO\FRUUHODWHGZLWK.QHH(;37$6,DWƒVEXWQRVLJQL¿FDQWUHODWLRQVH[LVWEHWZHHQ3RZHUDQG isokinetic strength ASI. The same tendencies are presented in regression model where the Knee EX strength of 1 Nm/ NJDGV:NJF\FOLQJSRZHURQHRIGLIIHUHQFHLQVWUHQJWKHQGXUDQFHRI.QHH)/UHGXFHSRZHUDSSUR[LPDWHO\E\ :NJDQGRQHXQLWKLJKHUSHGDOOLQJVPRRWKQHVVYDOXHDVVRFLDWHVZLWK:NJSRZHUUHGXFWLRQ7KHUHVXOWVRIWKH FXUUHQWVWXG\FRQIRUPVRPHSUHYLRXV¿QGLQJV)LUVWO\ELODWHUDOO\VXPPDU\PD[LPDOSHUIRUPDQFHGRHVQRWRQO\GHSHQG RQPXVFOHVWUHQJWKEXWDOVRRQKRZHTXDOO\WKHVWUHQJWKLVGLVWULEXWHGEHWZHHQERG\VLGHV%DLOH\HWDO5DQQDPD HWDO DQGVHFRQGO\PRQLWRULQJOHJPXVFOHVVWUHQJWKV\PPHWU\GXULQJWKHWUDLQLQJSURFHVVPD\SURYLGHDGGLWLRQDO information in order to develop strength training programs. 

Kinesiology of Top-level Sport

Power (W/kg) Pedalling Smoothness (%)

8th International Scientific Conference on Kinesiology, 2017, Opatija, Croatia

7DEOH5HJUHVVLRQPRGHORIVHFRQGVSULQWF\FOLQJSHUIRUPDQFHPHDVXUHGDVDERG\PDVVFRUUHFWHGDYHUDJHSRZHU:NJ N=36 R

0.820

R Square

0.673

Adjusted R Square

0.640

Unstandardized Coefficients B

Std. Error

Standardized Coefficients

t

Sig.

Beta

(Constant)

8.645

1.540

Knee Extensors AvT at 180 ƒ/s (Nm/kg)

2.822

0.506

Knee Flexsors PT ASI at 180 ƒ/s (%)

-0.038

0.015

-0.269

-2.475

0.019

Pedalling Smoothness (%)

-0.079

0.032

-0.265

-2.454

0.020

Full Model

0.000

Dependent Variable: Power (W/kg)

0.620

5.612

0.000

5.580

0.000

Kinesiology of Top-level Sport

Conclusion 7KHUHVXOWVRIWKHFXUUHQWVWXG\GHPRQVWUDWHWKDWGXULQJWKHVHFRQGPD[LPDOF\FOLQJVSULQWWKHVWURQJHVWSUHGLFWRU RISHUIRUPDQFHZDVNQHHH[WHQVRUV¶DELOLW\WRJHQHUDWHKLJKDYHUDJHWRUTXHGXULQJUHSHWLWLRQV+RZHYHUDWKLJKHU cycling power there was evident reduction in the smoothness of pedalling witch may have a potentially detrimental effect, DQGWKDWZDVDOVRUHÀHFWHGLQWKHELODWHUDODV\PPHWU\RINQHHÀH[RUVVWUHQJWKDQGVWUHQJWKHQGXUDQFHSHUIRUPDQFHDPRQJ the test subjects.

References 1.

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