Akutni učinak kofeina na jakost i snagu mišića natkoljenice

master's thesis

• Title (english): Acute effect of caffeine on strength and power of thigh muscles
• Author: David Šmital
• Mentor: Pavle Mikulić (mentor)
• Committee member: Pavle Mikulić (predsjednik povjerenstva)
• Committee member: Cvita Gregov (član povjerenstva)
• Committee member: Saša Vuk (član povjerenstva)
• Granter: University of Zagreb; Faculty of Kinesiology; Zagreb
• Defense date and country: 2021-07-09, Croatia
• Scientific / art field, discipline and subdiscipline: SOCIAL SCIENCES; Kinesiology

Abstract

Cilj ovog randomiziranog, dvostruko slijepog, placebom kontroliranog istraživanja, bio je utvrditi akutni učinak doze kofeina od 6 mg/kg na jakost i snagu mišića prednje i stražnje strane natkoljenice kod osoba s iskustvom u treningu s otporom. U istraživanje je bilo uključeno 25 ispitanika muškog spola s barem 12 mjeseci iskustva u treningu s otporom u dobi od (AS±SD) 23,1±2 godine, visine 181,5±7,3 cm te mase 83,2±11,3 kg koji su tijekom tri dolaska u laboratorij imali upoznavanje s istraživanjem i nakon toga testiranje izvedbe nakon konzumacije kofeina od 6 mg/kg tjelesne mase te nakon konzumacije iste količine placeba. Zadatak ispitanika bila je izvedba na izokinetičkom uređaju gdje se pratio vršni moment sile (u N/m) kao pokazatelj jakosti i prosječni izlaz snage (u W) kao pokazatelj snage pri izvedbi ekstenzije i fleksije potkoljenice u zglobu koljena pri kutnoj brzini od 60 stupnjeva u sekundi (°/s). U uvjetima uzimanja kofeina, dobiveno je statistički značajno poboljšanje izvedbe (p<0,05) u odnosu na placebo kod svih testova koji su se pratili: vršni moment sile-fleksija (p<0,05; +4,1%), vršni moment sile-ekstenzija (p<0,05; +5,9%), prosječna snaga-fleksija (p<0,05; +5,3%), prosječna snaga-ekstenzija (p<0,05; +6,6%). Dakle, statistički značajno povećanje rezultata zabilježeno je u vrijednostima vršnog momenta sile i prosječne snage pri kutnoj brzini od 60°/s i za mišiće fleksore i za mišiće ekstenzore u zglobu koljena. Zaključno, kofein kao ergogeno sredstvo može predstavljati dodatak prehrani kojeg će sportaši i rekreativni vježbači koristiti prije treninga ili natjecanja u svrhu akutnog podizanja jakosti i snage mišića natkoljenice, a time i mogućeg poboljšanja ukupne tjelesne odnosno sportske izvedbe.

Abstract (english)

The aim of this randomized, double blind, placebo controlled research was to determine the acute effect of a 6 mg/kg dose of caffeine on the strength and power of the muscles of the front and rear side of the thigh in people with experience in training with external load. Included in the research were 25 male examinees with at least 12 months of experience in training with external load, aged (AS±SD) 23.08±2.01 years, with a height of 181.51±7.26 cm, and a mass of 83.16±11.28 kg, who, during three visits of the lab, were acquainted with the research and performance testing, after consuming 6 mg/kg of caffeine along with the same amount of placebo. The task of the examinees was to perform on an isokinetic machine, where peak torque of force was observed as an indicator of strength, and average power as an indicator of power during extension and flexion in the knee joint at an angular velocity of 60 degrees per second (°/s). In caffeine conditions, a statistically significant difference (p<0.05) was obtained, in comparison with the placebo, in all tests which were observed: peak torque of flexion force (p<0,05; +4,1%), peak torque of extension force (p<0,05; +5,9%), average flexion power (p<0,05; +5,3%), and average extension power (p<0,05; +6,6%). Hence, a statistically significant increase in results was recorded in the values of peak torque of force at an angular velocity of 60°/s for knee flexors and extensors, along with their average power. In conclusion, caffeine as an ergogenic medium can represent a substance which individuals will use before trainings or competitions with the purpose of acutely increasing strength and power of thigh muscles, and accordingly, sports performance.

• Keywords: kofein; jakost; snaga; izokinetički uređaj
• Keywords (english): caffeine; strength; power; isokinetic machine
• Language: croatian
• URN:NBN: urn:nbn:hr:117:832739
• Study programme: Title: Kinesiology; specializations in: Kinesiology in Education and Track-and-Field, Kinesiology in Education and Fitness, Kinesiology in Education and Wrestling, Kinesiology in Education and Sailing, Kinesiology in Education and Windsurfing, Kinesiology in Education and Judo, Kinesiology in Education and Kayaking, Kinesiology in Education and Kinesiological Recreation, Kinesiology in Education and Kinesitherapy, Kinesiology in Education and Physical Conditioning of Athletes, Kinesiology in Education and Basketball, Kinesiology in Education and Football, Kinesiology in Education and Volleyball, Kinesiology in Education and Basic Kinesiological Transformations, Kinesiology in Education and Dancing, Kinesiology in Education and Swimming, Kinesiology in Education and Rhythmic Gymnastics, Kinesiology in Education and Handball, Kinesiology in Education and Skiing, Kinesiology in Education and Artistic Gymnastics, Kinesiology in Education and Management of Sport, Kinesiology in Education and Tennis, Kinesiology in Education and Rowing; Course: Kinesiology in Education and Physical Conditioning of Athletes; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar / magistra kineziologije (magistar / magistra kineziologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to authenticated users
• Created on: 2021-11-09 14:08:21