Despite the increasing scientific interest in the relationship between pacing and performance in endurance sports, little information is available about pacing and pacing variation in ultra-endurance ...events such as ultra-triathlons. Therefore, we aimed to investigate the trends of pacing, pacing variation, the influence of age, sex, and performance level in ultra-triathlons of different distances. We analysed 969 finishers (849 men, 120 women) in 46 ultra-triathlons longer than the original Ironman® distance (e.g., Double-, Triple-, Quintuple- and Deca Iron ultra-triathlons) held from 2004 to 2015. Pacing speed was calculated for every cycling and running lap. Pacing variation was calculated as the coefficient of variation (%) between the average speed of each lap. Performance level (i.e., fast, moderate, slow) was defined according to the 33.3 and 66.6 percentile of the overall race time. A multivariate analysis (two-way ANOVA) was applied for the overall race time as the dependent variable with 'sex' and 'age group' as independent factors. Another multivariate model with 'age' and 'sex' as covariates (two-way ANCOVA) was applied with pacing variation (cycling and running) as the dependent variable with 'race' and 'performance level' as independent factors. Different pacing patterns were observed by event and performance level. The general pacing strategy applied was a positive pacing. In Double and Triple Iron ultra-triathlon, faster athletes paced more evenly with less variation than moderate or slower athletes. The variation in pacing speed increased with the length of the race. There was no significant difference in pacing variation between faster, moderate, and slower athletes in Quintuple and Deca Iron ultra-triathlon. Women had a slower overall performance than men. The best overall times were achieved at the age of 30-39 years. Successful ultra-triathlon athletes adapted a positive pacing strategy in all race distances. The variation in pacing speed increased with the length of the race. In shorter ultra-triathlon distances (i.e., Double and Triple Iron ultra-triathlon), faster athletes paced more evenly with less variation than moderate or slower athletes. In longer ultra-triathlon distances (i.e., Quintuple and Deca Iron ultra-triathlon), there was no significant difference in pacing variation between faster, moderate, and slower athletes.
Germplasm collection as a source of variability and genetic diversity must be evaluated for an efficient management and effective utilization. This research was aimed to evaluate the agronomic value ...of red clover germplasm collection, to group the cultivars and population according to their morpho-agronomical traits, and to select valuable materials for future breeding programs. Thirty red clover cultivars and populations of different geographical origin were included in the study. Investigation was carried out at the experimental field of the Agricultural Institute Osijek in Croatia. The field trial was arranged in a randomized block design with four replications. Each plot included twenty spaced plants (50 x 50 cm) of each cultivar/population. During two consecutive years (2006, 2007) the following data were collected: yields of green mass, dry matter and seed (g/plant), plant height (cm), dry matter content (%), persistence (%), flowering time. The analysis of variance was carried out for all the traits, with the exception of seed yield and flowering time (which were not recorded as replicated data), using PROC GLM of SAS 9.1. Differences among cultivars/populations were highly significant for all analyzed traits. Hierarchical cluster analysis (Ward method) based on the seven morpho-agronomic traits allowed the identification of six groups of red clover cultivars/populations. This research shows that there is a great genetic variability in the investigated germplasm collection. The most promising materials were selected to form a new breeding gene pool that could be helpful for the improvement of our red clover breeding programme.
Swimming Three Ice Miles within Fifteen Hours Stjepanovic, Mirko; Nikolaidis, Pantelis T.; Knechtle, Beat
Chinese journal of physiology,
08/2017, Letnik:
60, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Ice Mile swimming (1608 m in water of below 5°C) is becoming increasingly popular. This case study aimed to identify body core temperature and selected haematological and biochemical parameters ...before and after repeated Ice Miles. An experienced ice swimmer completed three consecutive Ice Miles within 15 h. Swim times, body core temperatures, and selected urinary and haematological parameters were recorded. Body core temperature reached its maximum between 5, 8 and 15 min after immersion (37.7°C, 38.1°C, and 38.0°C, respectively). The swimmer suffered hypothermia during the first Ice Mile (35.4°C) and body core temperature dropped furthermore to 34.5°C during recovery after the first Ice Mile. He developed a metabolic acidosis in both the first and the last Ice Mile (pH 7.31 and pH 7.34, respectively). We observed hyperkalaemia (K^+ ＞ 5.5 mM) after the second Ice Mile (6.9 mM). This was followed by a drop in K^+ to 3.7 mM after the third Ice Mile. Anticipatory thermogenesis (i.e. an initial increase of body core temperature after immersion in ice cold water) seems to be a physiological response in a trained athlete. The results suggest that swimming in ice-cold water leads to a metabolic acidosis, which the swimmer compensates with hyperventilation (i.e. leading to respiratory alkalosis). The shift of serum K^+ could increase the risk of a cardiac arrhythmia. Further studies addressing the physiology and potential risks of Ice Mile swimming are required to substantiate this finding.
Investigation of influences of precipitation and temperatures on grain yield of 8 genotypes of field pea was conducted in conditions of east Croatia. Locations, genotypes and interaction between them ...had highly significant effect on grain yield. Rainfall from February to May and rainfall during the pea vegetation were in very high positive correlation with average yield of pea, whilst temperatures in May and Jun were in negative correlation. Semigley soil type provided higher average yield than eutric cambisol in 2005.
ABSTRACTKnechtle, B, Stjepanovic, M, Knechtle, C, Rosemann, T, Sousa, CV, and Nikolaidis, PT. Physiological responses to swimming repetitive “Ice Miles.” J Strength Cond Res XX(X)000–000, 2018—“Ice ...Mile” swimming (i.e., 1,608 m in water of below 5° C) is becoming increasingly popular. Since the foundation of the International Ice Swimming Association (IISA) in 2009, official races are held as World Cup Races and World Championships. Ice swimming was a demonstration sport at the 2014 Winter Olympics in Sochi, Russia. This case study aimed to identify core body temperature and selected hematological and biochemical parameters before and after repeated “Ice Miles.” An experienced ice swimmer completed 6 consecutive Ice Miles within 2 days. Three Ice Miles adhered to the strict criteria for the definition of Ice Miles, whereas the other 3 were very close (i.e., 5.2, 6.1, and 6.6° C) to the temperature limit. Swimming times, changes in core body temperatures, and selected urinary and hematological parameters were recorded. The athlete showed after each Ice Mile a metabolic acidosis (i.e., an increase in lactate and TCO2; a decrease in base excess and HCO3) and an increase in blood glucose, cortisol, and creatine kinase concentration. The decrease in pH correlated significantly and negatively with the increase in cortisol level, indicating that this intense exercise causes a metabolic stress. The change in core body temperature between start and finish was negatively associated with metabolic acidosis. The increase in creatine kinase suggests skeletal muscle damages due to shivering after an Ice Mile. For athletes and coaches, swimming in cold water during Ice Miles leads to a metabolic acidosis, which the swimmer tries to compensate with a respiratory response. Considering the increasing popularity of ice swimming, the findings have practical value for swimmers and practitioners (e.g., coaches, exercise physiologists, and physicians) working with them because our results provide a detailed description of acute physiological responses to repeated swimming in cold conditions. These findings are of importance for athletes and coaches for National Championships and World Championships in Ice Swimming following the IISA rules.
Crvena djetelina (Trifolium pratense L.) je jedna od najznačajnijih višegodišnjih krmnih leguminoza, može se uzgajati u čistoj kulturi ili u smjesi s travama te koristiti u ishrani stoke kao zelena ...masa, sijeno i silaža. Ciljevi rada bili su procijeniti varijabilnost značajnih morfo-agronomskih svojstava 16 populacija/kultivara crvene djeteline domaćeg i stranog porijekla, utvrditi korelacijske veze između proučavanih svojstava, te identificirati moguće roditeljske komponente za potencijalni kultivar. Istraživanje je provedeno na lokaciji Osijek tijekom dvije godine (2004. i 2005.) a poljski pokus je postavljen po shemi randomiziranog bloka u tri ponavljanja. Analizirana su sljedeća morfo-agronomska svojstva: prinos zelene mase, suhe tvari i sjemena, sadržaj suhe tvari, visina biljaka, vrijeme cvjetanja te preživljavanje. Istraživane populacije/kultivari crvene djeteline značajno su varirale u svim proučavanim svojstvima. Utvrđene su značajne pozitivne korelacijske veze između prinosa zelene mase i suhe tvari, visine biljaka i prinosa, te sadržaja suhe tvari s prinosom suhe tvari i sjemena. Populacije PCD-6, PCD-7, PCD-2 i PCD-5 s obzirom na visoke prinose i povoljne vrijednosti ostalih proučavanih svojstava predstavljaju moguće roditeljske komponente za potencijalni kultivar. Njemački kultivari su zbog visokog prinosa zelene mase i suhe tvari (Temara) te izražene dugotrajnosti (Milvus) interesantna germplazma za daljnji oplemenjivački rad.
The paper aimed to determine yield and estimate pea grain yield stability of newly-created lines JSG-1 (cultivar in recognition process) as well as compare with foreign origin cultivars in ...agroecological area of east Slavonia. The trial was set up by a randomized block design on the experimental field of Agricultural Institute Osijek in four replicates in the five-year period (1998 – 2002). Six (five foreign and one inland) cultivars were included by the trial: Eiffil, Erbi, JP-5, JSG-1 (in a recognition process), Torsz and Baccara. Stability parameters were calculated by the grouping method after Francis and Kannenberg (1978) and by the model of individual stability estimation after Eberhart and Russel method (1966). According to Francis and Kannenberg, cultivars Eiffil, Erbi, JSG-1 and Baccara belonged to group I known for high yield and low trait varying coefficient, thus, represent stabile yield cultivars. According to regression coefficient and regression deviation variance the most stabile cultivar appeared to be cultivar JSG-1 (bi =1.06 and S2 di=0.010) and the lowest one was Torsz (bi =0.67 and S2 di =0.160). Cultivar Baccara (bi = 1.22 and S2 di =0.034) was comprised by the group of unstabile and adaptible for high-yielding environments.
Kvaliteta sjemena je značajan čimbenik u proizvodnji ratarskih kultura, a osobito kod lucerne i drugih sitnozrnih leguminoza. Širenjem proizvodnji sjemena lucerni sve više se širi vilina kosica u ...lucerni. Na području Slavonije i Baranje njeno prisustvo u lucerni cijeni se na oko 40% površina, a u Istri na crvenicama na oko 80%. U proizvodnji sjemena lucerne vilina kosica je karantenski korov, pa je treba uništavati kako mehaničkim mjerama, tako i pomoću herbicida. U ispitivanju su bila četiri herbicidna preparata (Kerb 50, Cidokor, Pivot 100 E i Aretit flussig) primijenjena pred početak vegetacije i nakon košje prvoga porasta u dvije količine na lokalitetima Osijek i Poreč u 1988. i 1989. godini. Ispitivanja su provedena na četiri i pet godina starom sjemenskom lucerištu. Ispitivanja u Osijeku su pokazala da je na površinama tretiranim Kerbom 50 (prosječno za dvije godine), bio najniži udio sjemena viline kosice u sjemenu lucerne (2,35%) dok je na netretiranoj površini udio sjemena viline kosice iznosio 9,29%. Ostali herbicidi dali su slabije rezultate. Ispitivanja u Poreču u sasvim drugom klimatu su pokazala daleko manju efikasnost herbicida nego u Osijeku. Najbolji rezultat i u Poreču postignut je tretiranjem Kerbom 50, ali je udio sjemena viline kosice u sjemenu lucerne iznosio 53,63%,dok je na netretiranoj površini iznosio 78,61% u prosjeku za dvije godine. I u Poreču su ostali ispitivani herbicidi dali slabije rezultate.
In the period 1993-1997 investigations were conducted on natural low marshy grassland of facies Arrhenatheretum elatioris alopecurosum located 60 km west of Osijek and 7 km south of the river Drava. ...Variants of nitrogen fertilization, NPK fertilizers and non-fertilized were comprised in the investigation. Presence of 121 plant species of which 22 grass and grass-like species, 12 legumes and 87 other plant species was determined. On the average of five years grassland fertilization affected changes in density value of all plant groups. The highest grass density was found out with the variant fertilized with N120P12K120 and the highest legumes density appeared to be on non-fertilized variant. In 1997 Centaurea jacea, Cerastium holosteoides and Myosotis arvensis dissapeared from plant density of other species due to fertilization and mowing effect. Grasses Alopercurus pratensis and Poa pratensis var. angustifolia as well as leguminoses Trfolim pratense and Lathyrus pratensis are especially characterized by good fodder and density value.
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