Differences in ventilatory and metabolic parameters obtained on rowing ergometer with and without sliders

S obzirom na dokazane prednosti upotrebe veslačkog ergometra s klizačima, cilj je bio utvrditi razlike u ventilacijskim i metaboličkim parametrima dobivenim u progresivnim testovima opterećenja na veslačkom ergometru bez i sa klizačima, kako bi se mogao donijeti zaključak da li je uputnije koristiti klizače prilikom testiranja na veslačkim ergometrima. Uzorak ispitanika se sastojao od 12 veslača nacionalnog i internacionalnog ranga (dob = 20,0 ± 3,1 godina, tjelesna težina = 82,9 ± 8,5 kg, tjelesna visina = 188,5 ± 7,3 cm). Analizirane su razlike pri anaerobnom pragu i maksimalnom dosegu u testu u varijablama apsolutnog i relativnog VO2, frekvencije srca, pulsa O2, apsolutnog i relativnog maksimalnog opterećenja, dišnog volumena, frekvencije disanja, minutne ventilacije te izdržaja u anaerobnoj zoni. Proveden je progresivni test opterećenja (start 150W uz porast opterećenja od 25W svakih 60 sek). Dobiveni rezultati ukazuju da ne postoje značajne razlike u vrijednostima apsolutnog i relativnog VO2max, kao ni u vrijednostima frekvencije srca i maksimalnog dostignutog opterećenja. Značajne razlike nisu utvrđene ni u ventilacijskim i metaboličkim parametrima pri anaerobnom pragu. Analizom Pearsonovog koeficijenta korelacije utvrđena je visoka povezanost ostvarenih rezultata u obje varijante test protokola u većini parametara. Iz dobivenih rezultata može se zaključiti da se u testiranjima mogu koristiti obadva načina korištenja ergometra, s napomenom da su svi ispitanici izjavili da ima korištenje klizača na ergometru pomaže u postizanju boljeg „osjećaja“ veslanja.Main goal of this study was to determine differences between ventilatory and metabolic parameters obtained in incremental test on two different rowing ergometers, one with and one without slides, so it would be possible to conclude is it recommendable to use sliders while testing on rowing ergometers. The sample was consisted of 12 male rowers of national and international level (age = 20,0 ± 3,1 years, body weight = 82,9 ± 8,5, body height = 188,5 ± 7,3 cm). Variables analyzed are absolute and relative VO2max, maximal heart rate, absolute and relative maximal load, maximal oxygen pulse, maximal heart ventilation rate, absolute and relative VO2 uptake at anaerobic threshold, load at anaerobic threshold, heart rate at anaerobic threshold, load at anaerobic threshold, endurance in anaerobic zone and load in anaerobic zone. The incremental test was used (start at 150W with incremental steps of 25W every 60 seconds). Obtained data shows that there are no significant differences in absolute and relative VO2max uptake, in maximum heart rate or maximal load achieved. Significant differences were not found in ventilatory and metabolic parameters at anaerobic threshold. By the analysis of Pearson’s correlation coefficient, a high correlation rate was determined in both test variations in most variables. From obtained results, it is possible to conclude that it is possible to use both of these two types of rowing ergometers, with remark that all the participants have stated that ergometer with slides helps them in achieving better “feel” of rowing

Differences in ventilatory and metabolic parameters obtained on rowing ergometer with and without sliders

S obzirom na dokazane prednosti upotrebe veslačkog ergometra s klizačima, cilj je bio utvrditi razlike u ventilacijskim i metaboličkim parametrima dobivenim u progresivnim testovima opterećenja na veslačkom ergometru bez i sa klizačima, kako bi se mogao donijeti zaključak da li je uputnije koristiti klizače prilikom testiranja na veslačkim ergometrima. Uzorak ispitanika se sastojao od 12 veslača nacionalnog i internacionalnog ranga (dob = 20,0 ± 3,1 godina, tjelesna težina = 82,9 ± 8,5 kg, tjelesna visina = 188,5 ± 7,3 cm). Analizirane su razlike pri anaerobnom pragu i maksimalnom dosegu u testu u varijablama apsolutnog i relativnog VO2, frekvencije srca, pulsa O2, apsolutnog i relativnog maksimalnog opterećenja, dišnog volumena, frekvencije disanja, minutne ventilacije te izdržaja u anaerobnoj zoni. Proveden je progresivni test opterećenja (start 150W uz porast opterećenja od 25W svakih 60 sek). Dobiveni rezultati ukazuju da ne postoje značajne razlike u vrijednostima apsolutnog i relativnog VO2max, kao ni u vrijednostima frekvencije srca i maksimalnog dostignutog opterećenja. Značajne razlike nisu utvrđene ni u ventilacijskim i metaboličkim parametrima pri anaerobnom pragu. Analizom Pearsonovog koeficijenta korelacije utvrđena je visoka povezanost ostvarenih rezultata u obje varijante test protokola u većini parametara. Iz dobivenih rezultata može se zaključiti da se u testiranjima mogu koristiti obadva načina korištenja ergometra, s napomenom da su svi ispitanici izjavili da ima korištenje klizača na ergometru pomaže u postizanju boljeg „osjećaja“ veslanja.Main goal of this study was to determine differences between ventilatory and metabolic parameters obtained in incremental test on two different rowing ergometers, one with and one without slides, so it would be possible to conclude is it recommendable to use sliders while testing on rowing ergometers. The sample was consisted of 12 male rowers of national and international level (age = 20,0 ± 3,1 years, body weight = 82,9 ± 8,5, body height = 188,5 ± 7,3 cm). Variables analyzed are absolute and relative VO2max, maximal heart rate, absolute and relative maximal load, maximal oxygen pulse, maximal heart ventilation rate, absolute and relative VO2 uptake at anaerobic threshold, load at anaerobic threshold, heart rate at anaerobic threshold, load at anaerobic threshold, endurance in anaerobic zone and load in anaerobic zone. The incremental test was used (start at 150W with incremental steps of 25W every 60 seconds). Obtained data shows that there are no significant differences in absolute and relative VO2max uptake, in maximum heart rate or maximal load achieved. Significant differences were not found in ventilatory and metabolic parameters at anaerobic threshold. By the analysis of Pearson’s correlation coefficient, a high correlation rate was determined in both test variations in most variables. From obtained results, it is possible to conclude that it is possible to use both of these two types of rowing ergometers, with remark that all the participants have stated that ergometer with slides helps them in achieving better “feel” of rowing

Analysis of metabolic demands of multidirectional running

Cilj: kretanje se u ekipnim sportovima vrlo često izvodi u pravcima koji nisu isključivo prema naprijed, no nedostaje informacija o zahtjevima takvih vrsta kretanja. Primarni cilj ovog istraživanja bila je usporedba vršnih vrijednosti primitka kisika koje se ostvaruju u progresivnom testu opterećenja i testovima kontinuiranog trčanja različitih smjerova. Sekundarni cilj je analiza razlike u brzini trčanja i frekvenciji srca pri 60, 70, 80, 90 i 100% od maksimalnog primitka kisika ostvarenog u progresivnom testu opterećenja i u testovima kontinuiranog trčanja različitim smjerovima. Metode: U eksperimentu je sudjelovalo 18 zdravih ispitanika muškog spola. Uključujući kriteriji za sudjelovanje u istraživanju bili su: (i) muški spol, stariji od 18 godina, tjelesno aktivni, (ii) minimalno 5 godina iskustva u bavljenju ekipnim sportovima (nogomet, košarka ili rukomet), te (iii) uspješno savladana tehnika bočnog trčanja na pokretnom sagu. U prvom dolasku ispitanicima je utvrđen maksimalni primitak kisika (VO2max) na progresivnom testu opterećenja (PTO). Dalje su ispitanici pristupili utvrđivanju vršnog primitka kisika (VO2p) u testovima kontinuiranog trčanja u različitim smjerovima (prema naprijed (KT-N), bočno u lijevu (KT-BL) te desnu (KT-BD) stranu i trčanje unatrag (KT-NT)). Tijekom testova KT, praćene su vrijednosti subjektivne procjene opterećenja (SPO), a po završetku protokola i vrijednosti subjektivne procjene opterećenja treninga (SPOt) u kontekstu kardiorespiratornog (KR) i neuromuskularnog (NM) opterećenja. Svi testovi su provedeni na pokretnom sagu u laboratorijskim uvjetima Sportsko dijagnostičkog centra Kineziološkog fakulteta Sveučilišta u Zagrebu. Po završetku glavnog dijela eksperimenta, ispitanicima je izmjerena maksimalna brzina trčanja. Brzina sprinta je izmjerena u četiri smjera, (i) prema naprijed (60m), bočno (40m) u (ii) lijevu te (iii) desnu stranu te (iv) unatrag (40m). Rezultati: Jednosmjernom ANOVOM za ponovljena mjerenja utvrđena je statistički značajna razlika (p=0,001) u VO2max između različitih smjerova trčanja. Usporedbom parova utvrđena je značajna razlika između VO2max te VO2p dobivenog testom kontinuiranog trčanja (KT) unatrag (p=0,001; -6,0%). Usporedba VO2max između PTO i KT-BD nije bila značajna (p=0,562; -2,0%), kao ni usporedba VO2max između PTO i KT-BL (p=0,109; -3,4%). Analiza razlika brzine trčanja pri različitim intenzitetima (60, 70, 80, 90 i 100% VO2max), je ukazala na statistički značajnu razliku (p<0,05) u svim promatranim uvjetima. Analiza razlika frekvencije srca pri različitim intenzitetima (60, 70, 80, 90 i 100% VO2max), je ukazala na statistički značajnu razliku (p<0,05) na intenzitetima od 60% VO2max u PTO. Na intenzitetu od 70% VO2max utvrđena je razlika između trčanja naprijed i trčanja natrag, a na intenzitetu od 80% VO2max između trčanja naprijed i natrag te bočno lijevo. Na intenzitetima od 90 i 100% VO2max nije utvrđena statistički značajna razlika između promatranih uvjeta. Utvrđeno je da postoji statistički značajna razlika u relativnim vrijednostima primitka kisika između četiri uvjeta u kojima se izvodio kontinuirani test trčanja. Na svim brzinama najniža vrijednost VO2p je ostvarena u KT trčanja prema naprijed. Razlika se povećava s povećanjem intenziteta. Usporedbom parova (KT-N↔KT-NT; KT-N↔KT-BD; KT-N↔KT-BL) Wilcoxonovim testom sume rangova utvrđena je statistički značajna razlika na svim intenzitetima između protokola KT prema naprijed i svih drugih smjerova trčanja. Analiza vrijednosti subjektivne procjene opterećenja treninga (SPOt) je ukazala na više vrijednosti kardiorespiratornog opterećenja tijekom trčanja prema naprijed, dok su tijekom trčanja bočno i prema natrag značajno veće vrijednosti neuromuskularnog SPOt. Zaključak: Ovo istraživanje je pokazalo da se trčanjem bočno može dosegnuti razina maksimalnog primitka kisika. No, trčanjem prema natrag se ipak mogu dosegnuti samo nešto niže vrijednosti VO2max. Analiza ostalih rezultata ukazala je da vjerojatan razlog ovakvih rezultata donekle i u distribuciji razine treniranosti uključenih ispitanika. Naime, ispitanici s nižim VO2max su „lakše“ ostvarivali više vrijednosti VO2p tijekom trčanja bočno i prema natrag, dok kod ispitanika s višim vrijednostima VO2max je slučaj bio obrnut. Nadalje, zanimljivi rezultati su zabilježeni i u distribuciji SPOt, gdje se vidi da trčanje prema naprijed generira nešto više vrijednosti KR SPOt, dok trčanje prema natrag te bočno u obje strane ima značajno veće vrijednosti NM SPOt. To ukazuje da vjerojatno postoje značajna biomehanička ograničenja u trčanju bočno i prema natrag u odnosu na uobičajeno trčanje prema naprijed.Objective: movement in team sports is very often performed in directions that are not exclusively forward, but there is a lack of information about the requirements of such types of movement. The primary objective of this study was to compare the maximum values of oxygen uptake achieved in the graded exercise test and the continuous running tests of different running directions. The secondary objective is the analysis of the difference in running speed and heart rate values at 60, 70, 80, 90 and 100% of the maximum oxygen uptake achieved in the graded exercise test and in the continuous running tests in different directions. Methods: 18 healthy male subjects participated in the experiment. The inclusion criteria for participation in the study were: (i) male, over 18 years old, physically active, (ii) experience in team sports (soccer, basketball, or handball) for at least 5 years, and (iii) successfully mastered the lateral running technique on a motorized treadmill. In the first visit, the subjects' maximum oxygen intake (VO2max) was determined on the progressive graded exercise test (GXT). Next, the subjects proceeded to determine the peak oxygen uptake (VO2p) in tests of continuous running in different directions (forward (KT-FR), sideways to the left (KT-SL) and right (KTSR) side and backward running (KT-BR)). All tests were performed on a motorized treadmill in the laboratory conditions of the Sports Diagnostic Center Faculty of Kinesiology University of Zagreb. At the end of the main part of the experiment, the subjects' maximum sprint speed was measured. Maximum sprint speed was measured in four conditions, (i) forward (60m), sideways (40m) in (ii) left and (iii) right side and (iv) backward (40m). Results: One-way ANOVA for repeated measurements revealed a statistically significant main effect (p=0.001) for VO2max between different running directions. By comparing pairs, a significant difference was found between VO2max and VO2p obtained during the continuous running test (KT) backwards (p=0.001; -6.0%). The comparison of VO2max between GXT and KT-SR was not significant (p=0.562; -2.0%), and neither was the comparison of VO2max between GXT and KT-SL (p=0.109; -3.4%). The analysis of differences in running speed at different intensities (60, 70, 80, 90 and 100% VO2max) indicated a statistically significant difference (p<0.05) in all observed conditions. Analysis of heart rate differences at different intensities (60, 70, 80, 90 and 100% VO2max) indicated a statistically significant difference (p<0.05) at intensities of 60% VO2max in GXT. At an intensity of 70%VO2max, a difference was found between running forward and running, and at an intensity of 80%VO2max, between running forward and backward and sideways to the left. At the intensities of 90 and 100 %VO2max, no statistically significant difference was found between the observed conditions. It was found that there is a statistically significant difference in the relative values of VO2p between the four conditions in which the continuous running test was performed. At all speeds, the lowest VO2p value was achieved in forward running KT. The difference increases with increasing intensity. By comparing pairs (KT-FR↔KT-BR; KT-FR↔KT-SR; KT-FR↔KTSL) the Wilcoxon rank sum test revealed a statistically significant difference at all intensities between the forward KT protocol and all other running directions. Analysis of session rate of perceived exertion (sRPE) showed significantly higher values od cardiorespiratory sRPE during frontal running, while running sideways in both directions and backwards showed significantly higher values of neuromuscular sRPE. Conclusion: This study showed that sideways running can generate values of VO2max but the same thing is not possible while running backwards, even though high level of VO2max was reached during BR. Analysis of other results suggest that these results are probably due to the subject’s level of fitness. Namely, it seems that subjects with lower level of VO2max were more likely to achieve higher levels of VO2p during SR, SL and BR. On the other hand, subjects with higher level of VO2max achieved lower levels of VO2p during continuous running tests. Furthermore, interesting results were found in the analysis of sRPE which showed that we can expect lower values of cardiorespiratory sRPE during FR, while during sideways and BR significantly higher values of neuromuscular sRPE were found. That indicates that there are probably significant biomechanical limitations during sideways and BR in comparison to F

Analysis of metabolic demands of multidirectional running

Cilj: kretanje se u ekipnim sportovima vrlo često izvodi u pravcima koji nisu isključivo prema naprijed, no nedostaje informacija o zahtjevima takvih vrsta kretanja. Primarni cilj ovog istraživanja bila je usporedba vršnih vrijednosti primitka kisika koje se ostvaruju u progresivnom testu opterećenja i testovima kontinuiranog trčanja različitih smjerova. Sekundarni cilj je analiza razlike u brzini trčanja i frekvenciji srca pri 60, 70, 80, 90 i 100% od maksimalnog primitka kisika ostvarenog u progresivnom testu opterećenja i u testovima kontinuiranog trčanja različitim smjerovima. Metode: U eksperimentu je sudjelovalo 18 zdravih ispitanika muškog spola. Uključujući kriteriji za sudjelovanje u istraživanju bili su: (i) muški spol, stariji od 18 godina, tjelesno aktivni, (ii) minimalno 5 godina iskustva u bavljenju ekipnim sportovima (nogomet, košarka ili rukomet), te (iii) uspješno savladana tehnika bočnog trčanja na pokretnom sagu. U prvom dolasku ispitanicima je utvrđen maksimalni primitak kisika (VO2max) na progresivnom testu opterećenja (PTO). Dalje su ispitanici pristupili utvrđivanju vršnog primitka kisika (VO2p) u testovima kontinuiranog trčanja u različitim smjerovima (prema naprijed (KT-N), bočno u lijevu (KT-BL) te desnu (KT-BD) stranu i trčanje unatrag (KT-NT)). Tijekom testova KT, praćene su vrijednosti subjektivne procjene opterećenja (SPO), a po završetku protokola i vrijednosti subjektivne procjene opterećenja treninga (SPOt) u kontekstu kardiorespiratornog (KR) i neuromuskularnog (NM) opterećenja. Svi testovi su provedeni na pokretnom sagu u laboratorijskim uvjetima Sportsko dijagnostičkog centra Kineziološkog fakulteta Sveučilišta u Zagrebu. Po završetku glavnog dijela eksperimenta, ispitanicima je izmjerena maksimalna brzina trčanja. Brzina sprinta je izmjerena u četiri smjera, (i) prema naprijed (60m), bočno (40m) u (ii) lijevu te (iii) desnu stranu te (iv) unatrag (40m). Rezultati: Jednosmjernom ANOVOM za ponovljena mjerenja utvrđena je statistički značajna razlika (p=0,001) u VO2max između različitih smjerova trčanja. Usporedbom parova utvrđena je značajna razlika između VO2max te VO2p dobivenog testom kontinuiranog trčanja (KT) unatrag (p=0,001; -6,0%). Usporedba VO2max između PTO i KT-BD nije bila značajna (p=0,562; -2,0%), kao ni usporedba VO2max između PTO i KT-BL (p=0,109; -3,4%). Analiza razlika brzine trčanja pri različitim intenzitetima (60, 70, 80, 90 i 100% VO2max), je ukazala na statistički značajnu razliku (p<0,05) u svim promatranim uvjetima. Analiza razlika frekvencije srca pri različitim intenzitetima (60, 70, 80, 90 i 100% VO2max), je ukazala na statistički značajnu razliku (p<0,05) na intenzitetima od 60% VO2max u PTO. Na intenzitetu od 70% VO2max utvrđena je razlika između trčanja naprijed i trčanja natrag, a na intenzitetu od 80% VO2max između trčanja naprijed i natrag te bočno lijevo. Na intenzitetima od 90 i 100% VO2max nije utvrđena statistički značajna razlika između promatranih uvjeta. Utvrđeno je da postoji statistički značajna razlika u relativnim vrijednostima primitka kisika između četiri uvjeta u kojima se izvodio kontinuirani test trčanja. Na svim brzinama najniža vrijednost VO2p je ostvarena u KT trčanja prema naprijed. Razlika se povećava s povećanjem intenziteta. Usporedbom parova (KT-N↔KT-NT; KT-N↔KT-BD; KT-N↔KT-BL) Wilcoxonovim testom sume rangova utvrđena je statistički značajna razlika na svim intenzitetima između protokola KT prema naprijed i svih drugih smjerova trčanja. Analiza vrijednosti subjektivne procjene opterećenja treninga (SPOt) je ukazala na više vrijednosti kardiorespiratornog opterećenja tijekom trčanja prema naprijed, dok su tijekom trčanja bočno i prema natrag značajno veće vrijednosti neuromuskularnog SPOt. Zaključak: Ovo istraživanje je pokazalo da se trčanjem bočno može dosegnuti razina maksimalnog primitka kisika. No, trčanjem prema natrag se ipak mogu dosegnuti samo nešto niže vrijednosti VO2max. Analiza ostalih rezultata ukazala je da vjerojatan razlog ovakvih rezultata donekle i u distribuciji razine treniranosti uključenih ispitanika. Naime, ispitanici s nižim VO2max su „lakše“ ostvarivali više vrijednosti VO2p tijekom trčanja bočno i prema natrag, dok kod ispitanika s višim vrijednostima VO2max je slučaj bio obrnut. Nadalje, zanimljivi rezultati su zabilježeni i u distribuciji SPOt, gdje se vidi da trčanje prema naprijed generira nešto više vrijednosti KR SPOt, dok trčanje prema natrag te bočno u obje strane ima značajno veće vrijednosti NM SPOt. To ukazuje da vjerojatno postoje značajna biomehanička ograničenja u trčanju bočno i prema natrag u odnosu na uobičajeno trčanje prema naprijed.Objective: movement in team sports is very often performed in directions that are not exclusively forward, but there is a lack of information about the requirements of such types of movement. The primary objective of this study was to compare the maximum values of oxygen uptake achieved in the graded exercise test and the continuous running tests of different running directions. The secondary objective is the analysis of the difference in running speed and heart rate values at 60, 70, 80, 90 and 100% of the maximum oxygen uptake achieved in the graded exercise test and in the continuous running tests in different directions. Methods: 18 healthy male subjects participated in the experiment. The inclusion criteria for participation in the study were: (i) male, over 18 years old, physically active, (ii) experience in team sports (soccer, basketball, or handball) for at least 5 years, and (iii) successfully mastered the lateral running technique on a motorized treadmill. In the first visit, the subjects' maximum oxygen intake (VO2max) was determined on the progressive graded exercise test (GXT). Next, the subjects proceeded to determine the peak oxygen uptake (VO2p) in tests of continuous running in different directions (forward (KT-FR), sideways to the left (KT-SL) and right (KTSR) side and backward running (KT-BR)). All tests were performed on a motorized treadmill in the laboratory conditions of the Sports Diagnostic Center Faculty of Kinesiology University of Zagreb. At the end of the main part of the experiment, the subjects' maximum sprint speed was measured. Maximum sprint speed was measured in four conditions, (i) forward (60m), sideways (40m) in (ii) left and (iii) right side and (iv) backward (40m). Results: One-way ANOVA for repeated measurements revealed a statistically significant main effect (p=0.001) for VO2max between different running directions. By comparing pairs, a significant difference was found between VO2max and VO2p obtained during the continuous running test (KT) backwards (p=0.001; -6.0%). The comparison of VO2max between GXT and KT-SR was not significant (p=0.562; -2.0%), and neither was the comparison of VO2max between GXT and KT-SL (p=0.109; -3.4%). The analysis of differences in running speed at different intensities (60, 70, 80, 90 and 100% VO2max) indicated a statistically significant difference (p<0.05) in all observed conditions. Analysis of heart rate differences at different intensities (60, 70, 80, 90 and 100% VO2max) indicated a statistically significant difference (p<0.05) at intensities of 60% VO2max in GXT. At an intensity of 70%VO2max, a difference was found between running forward and running, and at an intensity of 80%VO2max, between running forward and backward and sideways to the left. At the intensities of 90 and 100 %VO2max, no statistically significant difference was found between the observed conditions. It was found that there is a statistically significant difference in the relative values of VO2p between the four conditions in which the continuous running test was performed. At all speeds, the lowest VO2p value was achieved in forward running KT. The difference increases with increasing intensity. By comparing pairs (KT-FR↔KT-BR; KT-FR↔KT-SR; KT-FR↔KTSL) the Wilcoxon rank sum test revealed a statistically significant difference at all intensities between the forward KT protocol and all other running directions. Analysis of session rate of perceived exertion (sRPE) showed significantly higher values od cardiorespiratory sRPE during frontal running, while running sideways in both directions and backwards showed significantly higher values of neuromuscular sRPE. Conclusion: This study showed that sideways running can generate values of VO2max but the same thing is not possible while running backwards, even though high level of VO2max was reached during BR. Analysis of other results suggest that these results are probably due to the subject’s level of fitness. Namely, it seems that subjects with lower level of VO2max were more likely to achieve higher levels of VO2p during SR, SL and BR. On the other hand, subjects with higher level of VO2max achieved lower levels of VO2p during continuous running tests. Furthermore, interesting results were found in the analysis of sRPE which showed that we can expect lower values of cardiorespiratory sRPE during FR, while during sideways and BR significantly higher values of neuromuscular sRPE were found. That indicates that there are probably significant biomechanical limitations during sideways and BR in comparison to F

Analysis of metabolic demands of multidirectional running

Cilj: kretanje se u ekipnim sportovima vrlo često izvodi u pravcima koji nisu isključivo prema naprijed, no nedostaje informacija o zahtjevima takvih vrsta kretanja. Primarni cilj ovog istraživanja bila je usporedba vršnih vrijednosti primitka kisika koje se ostvaruju u progresivnom testu opterećenja i testovima kontinuiranog trčanja različitih smjerova. Sekundarni cilj je analiza razlike u brzini trčanja i frekvenciji srca pri 60, 70, 80, 90 i 100% od maksimalnog primitka kisika ostvarenog u progresivnom testu opterećenja i u testovima kontinuiranog trčanja različitim smjerovima. Metode: U eksperimentu je sudjelovalo 18 zdravih ispitanika muškog spola. Uključujući kriteriji za sudjelovanje u istraživanju bili su: (i) muški spol, stariji od 18 godina, tjelesno aktivni, (ii) minimalno 5 godina iskustva u bavljenju ekipnim sportovima (nogomet, košarka ili rukomet), te (iii) uspješno savladana tehnika bočnog trčanja na pokretnom sagu. U prvom dolasku ispitanicima je utvrđen maksimalni primitak kisika (VO2max) na progresivnom testu opterećenja (PTO). Dalje su ispitanici pristupili utvrđivanju vršnog primitka kisika (VO2p) u testovima kontinuiranog trčanja u različitim smjerovima (prema naprijed (KT-N), bočno u lijevu (KT-BL) te desnu (KT-BD) stranu i trčanje unatrag (KT-NT)). Tijekom testova KT, praćene su vrijednosti subjektivne procjene opterećenja (SPO), a po završetku protokola i vrijednosti subjektivne procjene opterećenja treninga (SPOt) u kontekstu kardiorespiratornog (KR) i neuromuskularnog (NM) opterećenja. Svi testovi su provedeni na pokretnom sagu u laboratorijskim uvjetima Sportsko dijagnostičkog centra Kineziološkog fakulteta Sveučilišta u Zagrebu. Po završetku glavnog dijela eksperimenta, ispitanicima je izmjerena maksimalna brzina trčanja. Brzina sprinta je izmjerena u četiri smjera, (i) prema naprijed (60m), bočno (40m) u (ii) lijevu te (iii) desnu stranu te (iv) unatrag (40m). Rezultati: Jednosmjernom ANOVOM za ponovljena mjerenja utvrđena je statistički značajna razlika (p=0,001) u VO2max između različitih smjerova trčanja. Usporedbom parova utvrđena je značajna razlika između VO2max te VO2p dobivenog testom kontinuiranog trčanja (KT) unatrag (p=0,001; -6,0%). Usporedba VO2max između PTO i KT-BD nije bila značajna (p=0,562; -2,0%), kao ni usporedba VO2max između PTO i KT-BL (p=0,109; -3,4%). Analiza razlika brzine trčanja pri različitim intenzitetima (60, 70, 80, 90 i 100% VO2max), je ukazala na statistički značajnu razliku (p<0,05) u svim promatranim uvjetima. Analiza razlika frekvencije srca pri različitim intenzitetima (60, 70, 80, 90 i 100% VO2max), je ukazala na statistički značajnu razliku (p<0,05) na intenzitetima od 60% VO2max u PTO. Na intenzitetu od 70% VO2max utvrđena je razlika između trčanja naprijed i trčanja natrag, a na intenzitetu od 80% VO2max između trčanja naprijed i natrag te bočno lijevo. Na intenzitetima od 90 i 100% VO2max nije utvrđena statistički značajna razlika između promatranih uvjeta. Utvrđeno je da postoji statistički značajna razlika u relativnim vrijednostima primitka kisika između četiri uvjeta u kojima se izvodio kontinuirani test trčanja. Na svim brzinama najniža vrijednost VO2p je ostvarena u KT trčanja prema naprijed. Razlika se povećava s povećanjem intenziteta. Usporedbom parova (KT-N↔KT-NT; KT-N↔KT-BD; KT-N↔KT-BL) Wilcoxonovim testom sume rangova utvrđena je statistički značajna razlika na svim intenzitetima između protokola KT prema naprijed i svih drugih smjerova trčanja. Analiza vrijednosti subjektivne procjene opterećenja treninga (SPOt) je ukazala na više vrijednosti kardiorespiratornog opterećenja tijekom trčanja prema naprijed, dok su tijekom trčanja bočno i prema natrag značajno veće vrijednosti neuromuskularnog SPOt. Zaključak: Ovo istraživanje je pokazalo da se trčanjem bočno može dosegnuti razina maksimalnog primitka kisika. No, trčanjem prema natrag se ipak mogu dosegnuti samo nešto niže vrijednosti VO2max. Analiza ostalih rezultata ukazala je da vjerojatan razlog ovakvih rezultata donekle i u distribuciji razine treniranosti uključenih ispitanika. Naime, ispitanici s nižim VO2max su „lakše“ ostvarivali više vrijednosti VO2p tijekom trčanja bočno i prema natrag, dok kod ispitanika s višim vrijednostima VO2max je slučaj bio obrnut. Nadalje, zanimljivi rezultati su zabilježeni i u distribuciji SPOt, gdje se vidi da trčanje prema naprijed generira nešto više vrijednosti KR SPOt, dok trčanje prema natrag te bočno u obje strane ima značajno veće vrijednosti NM SPOt. To ukazuje da vjerojatno postoje značajna biomehanička ograničenja u trčanju bočno i prema natrag u odnosu na uobičajeno trčanje prema naprijed.Objective: movement in team sports is very often performed in directions that are not exclusively forward, but there is a lack of information about the requirements of such types of movement. The primary objective of this study was to compare the maximum values of oxygen uptake achieved in the graded exercise test and the continuous running tests of different running directions. The secondary objective is the analysis of the difference in running speed and heart rate values at 60, 70, 80, 90 and 100% of the maximum oxygen uptake achieved in the graded exercise test and in the continuous running tests in different directions. Methods: 18 healthy male subjects participated in the experiment. The inclusion criteria for participation in the study were: (i) male, over 18 years old, physically active, (ii) experience in team sports (soccer, basketball, or handball) for at least 5 years, and (iii) successfully mastered the lateral running technique on a motorized treadmill. In the first visit, the subjects' maximum oxygen intake (VO2max) was determined on the progressive graded exercise test (GXT). Next, the subjects proceeded to determine the peak oxygen uptake (VO2p) in tests of continuous running in different directions (forward (KT-FR), sideways to the left (KT-SL) and right (KTSR) side and backward running (KT-BR)). All tests were performed on a motorized treadmill in the laboratory conditions of the Sports Diagnostic Center Faculty of Kinesiology University of Zagreb. At the end of the main part of the experiment, the subjects' maximum sprint speed was measured. Maximum sprint speed was measured in four conditions, (i) forward (60m), sideways (40m) in (ii) left and (iii) right side and (iv) backward (40m) Results: One-way ANOVA for repeated measurements revealed a statistically significant main effect (p=0.001) for VO2max between different running directions. By comparing pairs, a significant difference was found between VO2max and VO2p obtained during the continuous running test (KT) backwards (p=0.001; -6.0%). The comparison of VO2max between GXT and KT-SR was not significant (p=0.562; -2.0%), and neither was the comparison of VO2max between GXT and KT-SL (p=0.109; -3.4%). The analysis of differences in running speed at different intensities (60, 70, 80, 90 and 100% VO2max) indicated a statistically significant difference (p<0.05) in all observed conditions. Analysis of heart rate differences at different intensities (60, 70, 80, 90 and 100% VO2max) indicated a statistically significant difference (p<0.05) at intensities of 60% VO2max in GXT. At an intensity of 70%VO2max, a difference was found between running forward and running, and at an intensity of 80%VO2max, between running forward and backward and sideways to the left. At the intensities of 90 and 100 %VO2max, no statistically significant difference was found between the observed conditions. It was found that there is a statistically significant difference in the relative values of VO2p between the four conditions in which the continuous running test was performed. At all speeds, the lowest VO2p value was achieved in forward running KT. The difference increases with increasing intensity. By comparing pairs (KT-FR↔KT-BR; KT-FR↔KT-SR; KT-FR↔KTSL) the Wilcoxon rank sum test revealed a statistically significant difference at all intensities between the forward KT protocol and all other running directions. Analysis of session rate of perceived exertion (sRPE) showed significantly higher values od cardiorespiratory sRPE during frontal running, while running sideways in both directions and backwards showed significantly higher values of neuromuscular sRPE. Conclusion: This study showed that sideways running can generate values of VO2max but the same thing is not possible while running backwards, even though high level of VO2max was reached during BR. Analysis of other results suggest that these results are probably due to the subject’s level of fitness. Namely, it seems that subjects with lower level of VO2max were more likely to achieve higher levels of VO2p during SR, SL and BR. On the other hand, subjects with higher level of VO2max achieved lower levels of VO2p during continuous running tests. Furthermore, interesting results were found in the analysis of sRPE which showed that we can expect lower values of cardiorespiratory sRPE during FR, while during sideways and BR significantly higher values of neuromuscular sRPE were found. That indicates that there are probably significant biomechanical limitations during sideways and BR in comparison to F

Accuracy of the 20-m shuttle run test for individualizing exercise intensity of high-intensity interval training

The aim of the study was to investigate the accuracy of the 20 m shuttle run test (20mSRT) for the prescription of high-intensity interval training (HIIT) and to examine the appropriate intensity, prescribed by the 20mSRT end-test speed, for the execution of HIIT. Twenty physical education students (age: 22.4 ± 0.8 years, body height: 175.7 ± 8.9 cm, body weight: 73.8 ± 13.4 kg) participated in the study. On two separate occasions the participants were first tested with a maximal incremental exercise test and the 20mSRT. On another two occasions they were required to perform a 10-minute HIIT session comprised of 15-s runs interspersed with 15-s passive recovery. The intensities of the HIIT sessions were either 100% (T100%) or 110% (T110%) of the end-test speed reached in the 20mSRT. Mean oxygen uptake (VO2) (84.4 ± 5.5% vs 77.8 ± 6.9% of VO2max), mean heart rate (HR) (93 ± 2.8% vs 87.6 ± 4.6% of HRmax), blood lactate concentration (12.6 ± 2.1 vs 5.4 ± 2.6 mmol/l), and ratings of perceived exertion (9.5 ± 0.5 vs 6.7 ± 1) were all significantly (p<.01) higher during T110% vs T100%. The percentage of the total exercise time spent ≥ 90% VO2max (37.6 ± 25.3 vs 18.6 ± 18.0%, p<.05) and ≥ 90% HRmax (73.9 ± 17.7% vs 37.5 ± 33.3, p<.001) were also significantly higher during T110%. The mean VO2 and HR coefficient of variation during T110% were 6.5 and 3%, respectively. The cardiorespiratory, metabolic, and perceptual responses to T110% were reflective of the responses typical for HIIT, while T100% induced insufficient physiological stress to enable optimal cardiorespiratory adaptation. Therefore, the intensity of 110% 20mSRT is preferable for inducing the appropriate acute physiological responses and the 20mSRT can be used to accurately prescribe HIIT