Jan Konarski

Prof. Dr. Jan Konarski

Theory of Sport Department, Poznań University of Physical Education
orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 August 2019 in Sports Medicine
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Journal Article
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RMRobert Malina
Robert Malina
SCSean P. Cumming
Sean P. Cumming
ARAlan DAVID Rogol
Alan DAVID Rogol
MCManuel J Coelho-e-Silva
Manuel J Coelho-e-Silva
AFAntónio Figueiredo
António Figueiredo
SKSławomir M. Kozieł
Sławomir M. Kozieł

1 February 2015 in International Journal of Sports Science & Coaching
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Journal Article
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MAMarcin Andrzejewski
Marcin Andrzejewski
JCJan Chmura
Jan Chmura
BPBeata Pluta
Beata Pluta
JKJan Konarski
Jan Konarski
This study presents a detailed analysis of sprinting activities and distance covered by professional soccer players in two seasons of the Europa League competition. The investigation considered such variables as the mean sprinting distance covered, duration of the rest pause between sprinting activities and maximal running speed recorded during the match. The study involved 147 soccer players participating in 10 matches played at one ground in the 2008–2009 and 2010–2011 Europa League seasons. Players' performance data were divided into two halves of matches and five playing positions. The study was carried out using data from Amisco Pro (version 1.0.2.). Results indicate wide variations in the analyzed variables, depending on the playing position on the pitch and tactical tasks. Individualization of training speed and endurance loads will help to optimize the training process of soccer players at different levels of their athletic skills.

20 August 2009 in Parasitology
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Journal Article
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WJW. Jarosz
W. Jarosz
HMH. Mizgajska-Wiktor
H. Mizgajska-Wiktor
PKP. Kirwan
P. Kirwan
JKJan Konarski
Jan Konarski
WRW. Rychlicki
W. Rychlicki
GWG. Wawrzyniak
G. Wawrzyniak
SUMMARY: Scarce and inconclusive information on general biological impact ofToxocarainvasion on paratenic hosts, and people in particular, has led us to undertake a comprehensive study of the problem. The study has been conducted in a rural environment, which is considered a toxocarosis risk factor. In total 200 soil samples have been screened forToxocaraeggs by flotation, of which 14·5% were positive. Backyards close to households were most heavily contaminated with infectious eggs – 21·7% of positive samples. ELISA serological tests performed on 242 lower-secondary students found 14·5% of the studied population to be definitely positive – 16·5% of boys and 12·8% of girls, respectively. The odds of being infected withToxocarawere 2 times (CI: 1·15–3·85) more likely for individuals who owned a cat than those who did not own a cat. Strong significant correlation between seropositivity and the presence of a dog in a household was found with boys. The level of developmental age was significantly higher in seropositive than in seronegative students. No significant correlation has been observed between the motor abilities and seropositivity of students. Seropositive boys had significantly lower end-of-year grades than their seronegative counterparts.

4 July 2018 in Annals of Human Biology
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JKJanusz Kwieciński
Janusz Kwieciński
JKJan Konarski
Jan Konarski
RSRyszard Strzelczyk
Ryszard Strzelczyk
MKMagdalena Krzykała
Magdalena Krzykała
AKAgata Konarska
Agata Konarska
RMRobert Malina
Robert Malina
Background: Comparisons of physical fitness in normal weight and overweight/obese youth generally highlight the negative consequences of an elevated BMI. In contrast, several studies of children and adolescents highlight the importance of variation in indicators of physical fitness across the full spectrum of BMIs from low through high. Aim: The purpose of the study was to evaluate relationships between specific physical fitness items and the BMI among youth. Subjects and methods: Height, weight and six physical fitness tests were measured in 1239 males and 903 females, aged 13–16 years; BMI (kg/m2) was calculated. Fitness tests were compared by weight status using sex-specific MANCOVAs, controlling for age. Sex-specific quadratic regressions of each fitness item on the BMI were also calculated. Results: The sprint, standing long jump and shuttle run indicated better performances in normal than in thin and overweight/obese boys; the latter groups did not differ. Thin and normal weight boys performed better than overweight/obese boys in sit-ups and distance run. Among girls, sit-ups differed as follows: normal > thin > overweight/obese. Thin and normal weight girls performed better than overweight/obese girls in the jump, distance run and shuttle run. Normal weight girls were faster in the sprint than the overweight/obese. The quadratic regressions indicated significant non-linear relationships between the BMI and all fitness items among boys and in four items among girls. Conclusion: Performances on fitness tests varied with weight status. Relationships between performances and the BMI were curvilinear except for the distance run and flexibility in girls.

1 January 2021 in Biology of Sport
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JKJan Konarski
Jan Konarski
MKMagdalena Krzykała
Magdalena Krzykała
MSMateusz Skrzypczak
Mateusz Skrzypczak
MNMonika Nowakowska
Monika Nowakowska
MCManuel Coelho-E-Silva
Manuel Coelho-E-Silva
RMRobert Malina
Robert Malina
Baseline characteristics of 31 healthy male U15 soccer players who were classified as select or non-select at the end of the season were compared. Players were 14.4 ± 0.54 years (13.6–15.3 years) at baseline; characteristics included body size, proportions and composition, estimated maturity...

18 October 2018 in PLOS ONE
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ATAnderson Santiago Teixeira
Anderson Santiago Teixeira
LGLuiz G A Guglielmo
Luiz G A Guglielmo
JFJuliano Fernandes-Da-Silva
Juliano Fernandes-Da-Silva
JKJan Konarski
Jan Konarski
DCDaniela Costa
Daniela Costa
RMRobert M Malina
Robert M Malina
Interrelationships among skeletal maturity status, body size, ventilator thresholds (VT) and peak oxygen uptake (VO2peak) were considered in 47 adolescent male soccer players aged 12.5–15.4 years. Body mass, stature, and the triceps and subscapular skinfolds were measured. The latter were used to estimate fat mass and fat-free mass. Skeletal age was assessed with the Fels method. VO2peak and VO2 at the first (VT1) and second (VT2) ventilatory thresholds were determined during an incremental maximal exercise test on a motorized treadmill. Ratio standards and allometric models were used in the analysis. Scaling exponents suggested linearity for all combinations between size descriptors and physiological variables, except between log-transformed values of VT1 and body mass (mL·kg-0.801·min, 95%CI: 0.649 to 0.952). Early maturing players attained greater values than players classified as “on-time” in skeletal maturity for the three ventilatory parameters expressed in absolute terms (d ranged from 0.65 to 0.71). The differences were attenuated after normalizing for mass descriptors using ratio standards and scaled variables (d ranged from 0.00 to 0.31). The results suggested significant variability between maturity groups when moving from VT1 to maximal metabolic conditions expressed by unit of stature (VT1: t = -2.413, p = 0.02, d = 0.60; VT2: t = -2.488, p = 0.02, d = 0.65; VO2peak: t = -2.475, p = 0.02, d = 0.65). Skeletal maturity status and associated variation in overall body size affects VT1, VT2 and VO2peak. The observed scaling of ventilatory outputs for body size may be related to the better running economy and smaller body size of average maturing athletes.