Kesk- ja pikamaajooksjate funktsionaalse ökonoomsuse ja võimsuse arendamise ning monitooringu võimalustest

https://www.ester.ee/record=b4063960*es

Antropometrijske i fiziološke odrednice izvedbe trčanja u trkača na srednje i duge pruge

The aim of the present study was to compare anthropometric, body composition and physiological parameters in middle- and long-distance runners of the same performance level and to identify variables that could predict the probability of being either a middle- or a long-distance runner. National-level middle-(n=20, body mass M=70.5, SD=6.3 kg, body height M=1.80, SD=0.04 m,) and long- (n=20, body mass M=69.0, SD=4.5 kg, body height M=1.81, SD=0.05 m) distance runners performed an incremental test on a treadmill. Anthropometric and body composition parameters were measured and different body length and mass ratios were calculated. Middle- and long-distance runners did not differ (p>.05) in their leg mass, length proportions, in their measured anthropometric or body composition parameters, except for the lower leg length. Performance in middle-distance runners was best described by the lower leg to upper leg mass ratio (Adj R2=.41; p<.05) and the second ventilatory threshold time (Adj R2=.33; p<.05), while the performance in long-distance runners was best described by the total time on a treadmill (Adj R2=.36; p<.05). The constructed model showed that VO2maxtime (OR=1.01, 95% CI 1.001-1.012) and age (OR=1.57; 95% CI 1.065-2.310) classified middle- and long-distance runners in their specialties. In conclusion, the results of the present study demonstrate the relevance of specific anthropometric parameters in predicting middle- but not longdistance running performance.Cilj je ovoga rada bio usporediti antropometrijske i fiziološke parametre te sastav tijela trkača na srednje i duge pruge koji su slične kvalitetne razine te identificirati varijable koje bi mogle prognozirati vjerojatnost njihova pripadanja skupini srednjoprugaša ili dugoprugaša. Trkači nacionalnog ranga koji trče na srednje (n=20, tjelesna masa M=70,5 kg, SD=6,3 kg, tjelesna visina M=1,80 m, SD=0,04 m) i duge pruge (n=20, tjelesna masa M=69,0 kg, SD=4,5 kg, tjelesna visina M=1,81 m, SD=0,05 m) podvrgnuti su progresivnom testu opterećenja. Izmjerene su antropometrijske karakteristike i sastav tijela te su izračunati omjeri longitudinalnih dimenzija različitih dijelova tijela i njihove mase. Srednjoprugaši i dugoprugaši se nisu razlikovali (p>0,05) u masi nogu, proporcijama dužine te izmjerenim antropometrijskim parametrima ili varijablama sastava tijela. Izvedba trčanja na srednje pruge najbolje je definirana pomoću varijable omjer mase potkoljenice i mase natkoljenice (Adj R2=0,41; p<0,05) te vremena postizanja drugog ventilacijskog praga (Adj R2=0,33; p<0,05), dok je uspješnost trčanja u dugoprugaša bila najbolje definirana pomoću varijable ukupno vrijeme trčanja na progresivnom testu opterećenja (Adj R2=0,36; p<0,05). Konstruirani model je pokazao da su vrijeme postizanja VO2max na progresivnom testu opterećenja (OR=1,01, 95% CI 1.001-1.012) i dob trkača (OR=1,57; 95% CI 1.065-2.310) najviše pridonijeli klasifikaciji trkača u njihove discipline. Zaključno, rezultati ovog istraživanja ukazali su na važnost specifičnih antropometrijskih karakteristika u predviđanju uspješnosti u trčanju na srednje pruge, ali ne i u trčanju na duge pruge

Pikamaajooksu ökonoomsuse ja võistlustulemuse antropomeetrilised ning füsiol oogilised determinandid: Eesti harrastusjooksjatest rahvusliku tasemega Kenya jooksjateni

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Ida-Aafrika, eriti Kenya jooksjad on domineerinud kesk- ja pikamaajooksudes rohkem kui 40 aastat. Sporditeadlased on proovinud selle piirkonna jooksjate edu selgitada nii geneetika, keskkonna, kultuuri, sotsiaalmajandusliku, elustiili kui ka treeningu faktoritega. Varasemalt on näidatud, et Kenya jooksjate maksimaalse hapnikutarbimise väärtused (laboratoorsetes tingimustes määratud parameeter, mis iseloomustab jooksja vastupidavuslikku töövõimet) ei erine oluliselt Euroopa jooksjate näitajatest ning seetõttu on pööratud üha suuremat tähelepanu jooksu ökonoomsuse uurimisele kui ühele sportliku saavutusvõime võtmefaktorile pikamaajooksus. Jooksu ökonoomsus on kompleksne faktor, mis iseloomustab kui efektiivselt jooksja hapnikku kasutab. Sellele parameetrile pööratakse erilist tähelepanu kõrgeimal sportlikul tasemel ning seetõttu on vajalik parem arusaamine ökonoomsuse seosest võistlustulemusega, keha koostise ning mõõtmete parameetritega erineva tasemega sportlastel. Käesolevaks hetkeks puudub üksmeel, kuidas jooksu ökonoomsus on seotud võistlustulemusega, millised faktorid mõjutavad ökonoomsust ja kas ökonoomsus on kesk- ja pikamaajooksjatel erinev. Käesoleva doktoritöö eesmärk oli uurida jooksu ökonoomsust ning võistlustulemusi Eesti harrastus- ja võistlustasemel jooksjatel ning ka Kenya rahvuslikul tasemel jooksjatel. Selleks viidi läbi kaks uuringut Eesti kesk- ja pikamaajooksjatega ning samu metoodikaid ja vahendeid kasutades üks uuring Kenyas sealsete kõrgel tasemel jooksjatega. Uuringud näitasid, et erinevusi Eesti võistlus- ning harrastusjooksjate ökonoomsuses ei ole võimalik selgitada erinevustega keha koostises (rasva- ning lihasmassi vahekord) ning võib arutleda, et erinevused jooksu ökonoomsuses on pigem mõjutatud erialasest treeningutst kui keha koostise parameetritest. Rahvuslikul tasemel Kenya jooksjate grupis kehvema ökonoomsusega jooksjad kompenseerisid seda kõrgema maksimaalse hapnikutarbimise võimega saavutamaks kõrgeid sportlikke tulemusi. Kokkuvõttes on antud doktoritöö tulemused kooskõlas ideega, et jooksu ökonoomsus on üks väga mitmest faktorist, mis selgitab kõrget sportlikku saavutusvõimet kesk- ja pikamaajooksudes.East African runners have dominated distance running for more than 40 years. Distance runners from Kenya hold over 55% of positions in all-time world top 20 list. Proposed explanations for the unprecedented success of Kenyan runners have included genetic, environmental, cultural, socioeconomic, lifestyle and training factors. From the early study conducted by Saltin et al. (1995) until to date there is lack of evidence for higher maximal oxygen uptake values (parameter determined in laboratory which characterise runners areobic capacity) in East African runners compared with Caucasian counterparts. Thus, it appears that elite East African runners do not have any specific advantage over non-African runners in terms of maximal oxygen uptake despite clear difference in performance. Therefore successful performance of distance runners, specifically those from East Africa, is generally attributed to better running economy. Altogether, to date there is no consensus which factors are responsible for superior running economy. In addition, there is equivocal data about how running economy is related to running performance, and about running economy between middle- and long-distance runners. Scientific community has agreed that running economy is not determined only by one parameter but it is rather more complex of factors to look at, especially at the highest level of human performance and therefore for better understanding of the interaction between running economy, performance, body composition as well as body lengths and circumferences on different levels of distance running is needed. Thus, the aim of the current thesis was to investigate running economy and performance in recreational and national level Estonian runners as well as elite level Kenyan distance runners. Present thesis concluded that running economy of Estonian competitive and recreational level runners cannot be explained by body composition and it can be argued that running economy is rather influenced by specific training than body composition variables. Inverse relationship between running economy and maximal oxygen uptake values in Kenyan runners would suggest that RE could be compensated for by maximal oxygen uptake to maintain high performance level. In conclusion, present findings are in line with the idea that running economy is only one of many factors explaining elite running performance

Pacing strategy of the finishers of the world marathon majors series

The purpose of the study was to describe pacing patterns of the finishers of the World Marathon Majors series and the effect of sex and age on the pacing pattern. The finishers of the World Marathon Majors series, a total of 69 814 male runners and 46 856 female runners with finishing time ≤ 6 hours were included in the analysis. Difference in pacing (dev%) was calculated as a difference between the first and second half of the marathon and expressed as a percentage of time. Analysis of variance (ANOVA) was used to evaluate the differences within and between the marathon time groups. The differences between the first and second half of the marathon by sex and age group were analysed using linear regression. The average difference between the first and second half of the marathon was 3.44±2.67% for male and 2.81±2.10% for female runners. Male runners with finishing times of 3:00 (h:min) and females with 4:00 (h:min) or slower had the significantly faster first half of the marathon compared to the evenly paced marathon (p=.038 and p=.001, respectively). Regression analysis revealed that female runners had 0.26% smaller difference between the first and second half of the race compared to male runners (R2=0.256; p<.001) when controlled for age and time group. Also, veterans (40 years and older) paced more evenly compared to non-veterans (R2=0.256; p<.001). In conclusion, irrespective of sex and age, faster finishers maintain a more constant velocity than the slower ones. In addition, women and veterans present more even pacing strategy compared to men and non-veterans, respectively

Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers

Distance events in Athletics include cross country, 10,000-m track race, half-marathon and marathon road races, and 20- and 50-km race walking events over different terrain and environmental conditions. Race times for elite performers span ∼26 min to >4 hr, with key factors for success being a high aerobic power, the ability to exercise at a large fraction of this power, and high running/walking economy. Nutrition-related contributors include body mass and anthropometry, capacity to use fuels, particularly carbohydrate (CHO) to produce adenosine triphosphate economically over the duration of the event, and maintenance of reasonable hydration status in the face of sweat losses induced by exercise intensity and the environment. Race nutrition strategies include CHO-rich eating in the hours per days prior to the event to store glycogen in amounts sufficient for event fuel needs, and in some cases, in-race consumption of CHO and fluid to offset event losses. Beneficial CHO intakes range from small amounts, including mouth rinsing, in the case of shorter events to high rates of intake (75–90 g/hr) in the longest races. A personalized and practiced race nutrition plan should balance the benefits of fluid and CHO consumed within practical opportunities, against the time, cost, and risk of gut discomfort. In hot environments, prerace hyperhydration or cooling strategies may provide a small but useful offset to the accrued thermal challenge and fluid deficit. Sports foods (drinks, gels, etc.) may assist in meeting training/race nutrition plans, with caffeine, and, perhaps nitrate being used as evidence-based performance supplements

Effects of EPO on blood parameters and running performance in Kenyan athletes

Introduction: Recombinant human erythropoietin (rHuEpo) administration enhances oxygen carrying capacity and performance at sea level. It remains unknown whether similar effects would be observed in chronic altitude-adapted endurance runners. The aim of this study was to assess the effects of rHuEpo on hematological and performance parameters in chronic altitude-adapted endurance runners as compared to sea level athletes. Methods: Twenty well-trained Kenyan endurance runners (KEN) living and training at approximately 2150 m received rHuEpo injections of 50 IU·kg−1 body mass every 2 d for 4 wk and responses compared with another cohort (SCO) that underwent an identical protocol at sea level. Blood samples were obtained at baseline, during rHuEpo administration and 4 wk after the final injection. A maximal oxygen uptake (V˙O2max) test and 3000-m time trial was performed before, immediately after and 4 wk after the final rHuEpo injection. Results: Hematocrit (HCT) and hemoglobin concentration (HGB) were higher in KEN compared to SCO before rHuEpo but similar at the end of administration. Before rHuEpo administration, KEN had higher V˙O2max and faster time trial performance compared to SCO. After rHuEpo administration, there was a similar increase in V˙O2max and time trial performance in both cohorts; most effects of rHuEpo were maintained 4 wk after the final rHuEpo injection in both cohorts. Conclusions: Four weeks of rHuEpo increased the HGB and HCT of Kenyan endurance runners to a lesser extent than in SCO (~17% vs ~10%, respectively) and these alterations were associated with similar improvements in running performance immediately after the rHuEpo administration (~5%) and 4 wk after rHuEpo (~3%)

Impact of sodium citrate ingestion during recovery after strenuous exercise in the heat on heart rate variability: A randomized, crossover study

Changes in hydration status influence plasma volume (PV) which is associated with post-exercise parasympathetic reactivation. The present study hypothesized that, after dehydrating cycling exercise in the heat (DE), stimulation of PV expansion with sodium citrate (CIT) supplementation would promote heart rate variability (HRV) recovery in endurance-trained men. Twelve participants lost 4% of body mass during DE. During subsequent 16-h recovery, participants consumed water ad libitum (CIT =5.5-L, PLC =5.1-L) and ate prescribed food supplemented with CIT or placebo in a randomized, double-blind, crossover manner. Relative changes in PV were assessed across DE and 16-h recovery. HRV was analyzed before and 16 h after DE in three conditions for altogether four 5-min periods: supine in a thermoneutral environment, supine in the heat (32°C, 46% relative humidity; 2 periods), and standing in the heat. A larger expansion of PV across 16-h recovery occurred in CIT compared to placebo trial (p 0.05). Increases in HR (p < 0.001) and lnLF/HF (p = 0.005) and decreases in lnRMSSD (p < 0.001) and lnSDNN (p < 0.001) occurred following DE in both trials. Larger PV expansion induced by CIT supplementation after DE does not improve recovery of HRV at rest and has no influence on HRV responsiveness in endurance-trained men

On anthropometric data of the male student candidates of the Institute of Sport Sciences and Physiotherapy at the University of Tartu in 2017

The purpose of this study was to investigate some anthropometric variables of student candidates of the Institute of Sport Sciences and Physiotherapy, Faculty of Medicine, University of Tartu in 2017. All anthropometric measurements were made according to the recommendations of R. Martin [7]. Comparison of the height and weight data of the studied subjects with the height and weight norms of Estonia provided by Kaarma et al. [9] revealed that the entrants were taller in height but with the same average weight. In our study, the somatotypes recommended by Kaarma et al. [9] were used for the first time on entrants to the university. Our study found that male student candidates’ body somatotypes were divided into SD classes as follows: small 8.6%, medium 22.9%, large 18.6%; subtypes of pycnomorphic somatotypes: 7.1% in class I, 1.4% in class II, and 8.6% in class III; leptomorphic somatotypes were divided: 11.4% in class I, none in class II and 31.4% in class III. Based on the recommendations of several authors, we calculated the ideal body weight for all the entrants enrolled in the study. Comparison of the average body weight of entrants with the average weight calculated using the ideal weight method revealed an interesting situation. Namely, the mean values calculated using the Devine (1974) formula did not differ statistically significantly from the mean of the measured weights (t=0.101, p&gt; 0.05). Neither did Devine’s (1974) ideal weight and BMI, Rohrer’s index and ponderal index calculated from it, and the body surface calculated according to the formulas of Dubois and Dubois and Mosteller differ from the actual figures

Effects of vitamin D supplementation in vitamin D deficient men involved in resistance training

Introduction. The prevalence of vitamin D (Vit-D) deficiency is high worldwide, especially in countries located at north and south latitudes above approximately 35 degrees. Vit-D supplementation has been shown to increase muscle strength in young adults. However, it remains unclear if Vit-D supplementation enhances the efficacy of resistance training (RT). The data regarding the impact of Vit-D supplementation on cardiorespiratory fitness in subjects with varying Vit-D status are controversial and there is lack of knowledge on the potential additive effect of Vit-D supplementation on anti-inflammatory responses to RT in Vit-D deficient young men. Aim. The aim of the study was to test two hypotheses. First, we hypothesised that Vit-D supplementation would enhance the RT-induced increases in muscle strength and lean body mass (LBM) in Vit-D deficient young men. Our second hypothesis was that Vit-D supplementation would have a positive effect on cardiorespiratory fitness (measured as maximal rate of oxygen consumption; VO2max) and potentiate anti-inflammatory effect of RT. Our hypotheses assume that these effects of Vit-D supplementation, if present, are more likely to occur in subjects with Vit-D deficiency than in individuals with normal Vit-D status. Material and methods. Thirty-nine young healthy men (baseline serum 25(OH)D<50 nmol/L) were quasi-randomly assigned to one of two groups that performed a 12-week supervised RT program concomitant with either Vit-D (8000 IU daily; VD) or placebo (PLC) supplementation. The RT program consisted of 7 exercises which were carried out on RT equipment. Energy and nutrient intake of the participants were monitored during the 2 nd, 6th and 11th week of RT. A graded maximal exercise test on a motorized treadmill was used to determine VO2max before and after the 12-week RT program. Results. During the 12-week RT, energy and nutrient (except Vit-D) intake and training loads did not differ in the two groups. Serum 25(OH)D levels increased from 36.3±9.2 to 142.4±21.9 nmol/L (P0.05) in PLC group. Muscle strength (1-repetition maximum) increased (P<0.05) to an equal extent in the two groups in 5 exercises performed on RT equipment whereas strength gains in chest press and seated row were greater (P<0.05) in PLC compared to VD group. Total and regional LBM (measured by DXA scan) increased (P<0.05) equally in the two groups. Android fat mass decreased (P<0.05) in VD group only. Baseline VO2max did not differ in the two groups (50.2±4.8 and 49.7±5.5 mL/kg/min in VD and PLC, respectively; p>0.05) and remained unchanged during the intervention. Serum interleukin-10/tumor necrosis factor alpha ratio, an indicator of chronic low-grade inflammation, increased significantly (30%, p=0.007; effect size 0.399) in VD but not in PLC group. Conclusions. In young healthy Vit-D deficient men participating in 12-week supervised RT, daily Vit-D supplementation of 8000 IU rapidly (within 4 weeks) eliminates Vit-D deficiency and improves inflammatory status. However, it does not enhance RT-induced muscle strength or LBM gains, does not increase total or regional fat mass reductions, and has no impact on cardiorespiratory fitness

Better economy in field running than on the treadmill: evidence from high-level distance runners

Given the ongoing interest in ways to improve the specificity of testing elite athletes in their natural environment, portable metabolic systems provide an opportunity to assess metabolic demand of exercise in sport-specific settings. Running economy (RE) and maximal oxygen uptake (VO2max) were compared between track and treadmill (1% inclination) conditions in competitive level European distance runners who were fully habituated to treadmill running (n = 13). All runners performed an exercise test on running track and on treadmill. While VO2max was similar on the track and on the treadmill (68.5 ± 5.3 vs. 71.4 ± 6.4 ml∙kg-1∙min-1, p = 0.105, respectively), superior RE was found on the track compared to the treadmill (215.4 ± 12.4 vs. 236.8 ± 18.0 O2 ml∙kg-1∙km-1, p &#60; 0.001). RE on the track was strongly correlated with RE on the treadmill (r = 0.719, p = 0.006). The present findings indicate that high-level distance runners have significantly better RE but not VO2max on the track compared to treadmill. This difference may be due to biomechanical adjustments. As RE is strongly correlated between the two conditions, it would be reasonable to assume that interventions affecting RE on the treadmill will also affect RE on the track