Soğuk ortam şartlarının, tercih edilen kadans ve hareket ekonomisine etkileri
Küçük Resim Yok
Tarih
2015
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Literatürde farklı ortam koşullarında kas aktivasyonu, akut metabolik yanıtlar, bisiklet performansında optimal kadans, mekanik verim vb. konularda çalışmalar taranmış olsa da soğuk ortam şartlarının tercih edilen bireysel kadans ve mekanik verimlilik (MV) üzerine etkilerini ortaya koyarak sonuçları etraflıca tartışan bir çalışma bulgusuna rastlanmamıştır. Bu tez çalışması soğuk ortam şartlarında tercih edilen bireysel kadans değerleri ve bu değerlerin mekanik verimlilik üzerine etkilerini ortaya koymak amacıyla yapıldı. Çalışmaya, orta düzey antrene 10 erkek triatlet ve bisikletçi (V ?O2maks; 57,3±4,2ml?dk-1?kg-1) gönüllü olarak katıldı. Adaptasyon seanslarının ardından, katılımcılar submaksimal ve maksimal testlerden sonra V ?O2maks'ın %60'ına denk gelen sabit yüklerle 20 dakikalık üç farklı egzersiz seansına 24 saat aralarla katıldılar. Bu egzersizler; i) Normal ortam koşullarında (20.1 ± 0.6°C, 60.8 ± 8.5% bağıl nem), bireysel tercih edilen kadansla (Nserbest), ii) Soğuk ortamda (8.1 ± 0.3°C, 66.9 ± 2.4% bağıl nem), bireysel tercih edilen kadansla (Sserbest), iii) Soğuk ortam koşullarında (8.4 ± 0.5°C, 64.9 ± 4.7% bağıl nem), Nserbest testinde tercih edilen bireysel kadans ortalamasının sabitlenmesiyle (Ssabit) her gün bir seans şeklinde düzenlenerek gerçekleştirildi. MV; bisiklet ergometresinden elde edilen mekanik güç değerleri ve Garby ve Astup (1987)'un metabolik güç formülünden elde edilen değerlerden "brüt" olarak hesaplandı. Deri sıcaklığı (Tderi) termal kamerayla, vücut iç sıcaklığı (Tiç) termisitörlü yutulabilir kapsüllerle ölçüldü. Ortam sıcaklığı, nem, oksijen ve karbondioksit düzeyleri sürekli kontrol altında tutuldu. Çalışmanın ana bulguları, sporcuların bireysel kadans tercihlerinin soğuk ortam şartlarında (104,4 devir·dk?1) normal ortama (97,8 devir·dk?1) göre %7 arttığını gösterdi (p=0,002). Normal ortam koşullarında (97,8 devir·dk?1) tercih edilen kadans değeri soğuk ortam şartlarında yapılan ölçümlerde (97,3 devir·dk?1) sabit tutulduğunda, soğuk ortamdaki MV (%17,6) normal ortam şartlarına (%18,8) kıyasla %6,4 oranında azaldı (p=0,002). Fakat soğuk ortam koşullarında 97,3 devir·dk?1'ya sabitlenen kadans sporcuların bireysel tercihlerine bırakıldığında, 104,4 devir·dk?1'ya kadar yükseldi (p=0,002). Sporcuların bireysel kadans tercihlerinde görülen bu artış, MV'yi %17,6'dan %18,4'e yükselterek %4,4'lük bir artışa neden oldu (p=0,024). Ek olarak tüm ortam koşullarında Tiç egzersiz süresince lineer olarak arttı (p?0,05). Tderi ise Ssabit ve Sserbest seansları süresince benzer düşüş paternleri gösterdi fakat Nserbest'in ilk 6 dakikasında düşüş görülmesine karşın devam eden sürede lineer bir artış trendi gösterdi (p?0,05) . Çalışmanın sonuçları olarak, soğuk ortam koşullarında kadansın sabit tutulmaya çalışılmasının bisiklet performansını bozduğunu buna karşın sporcuların bireysel kadans tercihlerinin kullanımıyla submaksimal iş yükünde verimin arttığı ortaya kondu
Although there are limited studies focused on metabolic and physiological adaptations on different ambient, muscle activations, optimal cadence or efficiency, there is no any study interested in freely choosing cadence (FCC) and mechanical efficiency (ME). Thus, the aim of the present study was to observe the effects of cold ambient (CA) on FCC and ME. 10 male moderately trained cyclists and triathletes volunteered for this study (V ?O2max: 57.3 ± 4.2 mL?min-1?kg-1). Following familiarization session, athletes performed submaximal and maximal graded exercise tests, and then, three constant-load submaximal exercise bouts continued 20 minutes were conducted at wattages corresponding to 60% of V ?O2max by using electromagnetically braked cycle ergometer in a climatic chamber. The submaximal exercise bouts consisted of i) normal ambient-FCC (NFCC; 20.1 ± 0.6°C, 60.8 ± 8.5% rh), ii) cold ambient-individually fixed to cadence used at NFCC (CFIXED, 8.4 ± 0.5°C, 64.9 ± 4.7% rh) and iii) cold ambient-FCC (CFCC, 8.1 ± 0.3°C, 66.9 ± 2.4% rh) were conducted with one day intervals. ME was calculated by external power output (Wattages) and the formula of metabolic power described by Garby and Astrup (1987). Skin temperature (Tskin) was measured by thermal camera while Tcore was recorded the ingestible core temperature sensor. Ambient temperature, humidity, oxygen and carbon-dioxide were automatically under-control by a climatic chamber. Main results showed that CFCC was 7% increase, when compared to NFCC (104.4 vs. 97.8 rpm, respectively; p=0.002). This change was 2.1% decrease in ME. When the NFCC was fixed to evaluate CFIXED, ME was 6.4% decrease from 18.8% to 17.6% (p=0.002). When cadence was allowed to participants' individual chose in cold ambient condition, it increased from 97.3 to 104.4 rpm with a concomitant increase in 4.4% of ME (17.6% vs. 18.4%, respectively; p=0.024). In addition, while Tcore linearly increased till the end of the exercise bouts in CFCC, NFCC and CFIXED (p=0.05), Tskin decreased throughout the exercises in CFCC and CFIXED (p=0.05); however, Tskin decreased in the first 6 minutes, and then gradually increased in NFCC (p=0.05). In conclusion, it should be allowed self-selected and relatively higher cadence rates in cold ambient conditions may increase cycling performance when compare to try to fix it.
Although there are limited studies focused on metabolic and physiological adaptations on different ambient, muscle activations, optimal cadence or efficiency, there is no any study interested in freely choosing cadence (FCC) and mechanical efficiency (ME). Thus, the aim of the present study was to observe the effects of cold ambient (CA) on FCC and ME. 10 male moderately trained cyclists and triathletes volunteered for this study (V ?O2max: 57.3 ± 4.2 mL?min-1?kg-1). Following familiarization session, athletes performed submaximal and maximal graded exercise tests, and then, three constant-load submaximal exercise bouts continued 20 minutes were conducted at wattages corresponding to 60% of V ?O2max by using electromagnetically braked cycle ergometer in a climatic chamber. The submaximal exercise bouts consisted of i) normal ambient-FCC (NFCC; 20.1 ± 0.6°C, 60.8 ± 8.5% rh), ii) cold ambient-individually fixed to cadence used at NFCC (CFIXED, 8.4 ± 0.5°C, 64.9 ± 4.7% rh) and iii) cold ambient-FCC (CFCC, 8.1 ± 0.3°C, 66.9 ± 2.4% rh) were conducted with one day intervals. ME was calculated by external power output (Wattages) and the formula of metabolic power described by Garby and Astrup (1987). Skin temperature (Tskin) was measured by thermal camera while Tcore was recorded the ingestible core temperature sensor. Ambient temperature, humidity, oxygen and carbon-dioxide were automatically under-control by a climatic chamber. Main results showed that CFCC was 7% increase, when compared to NFCC (104.4 vs. 97.8 rpm, respectively; p=0.002). This change was 2.1% decrease in ME. When the NFCC was fixed to evaluate CFIXED, ME was 6.4% decrease from 18.8% to 17.6% (p=0.002). When cadence was allowed to participants' individual chose in cold ambient condition, it increased from 97.3 to 104.4 rpm with a concomitant increase in 4.4% of ME (17.6% vs. 18.4%, respectively; p=0.024). In addition, while Tcore linearly increased till the end of the exercise bouts in CFCC, NFCC and CFIXED (p=0.05), Tskin decreased throughout the exercises in CFCC and CFIXED (p=0.05); however, Tskin decreased in the first 6 minutes, and then gradually increased in NFCC (p=0.05). In conclusion, it should be allowed self-selected and relatively higher cadence rates in cold ambient conditions may increase cycling performance when compare to try to fix it.
Açıklama
Anahtar Kelimeler
Spor, Sports