PHYSICAL ACTIVITY LEVEL HAS A GREAT INFLUENCE ON THE NUTRITIONAL STATUS OF ADOLESCENTS: A REVIEW ARTICLE
Purpose. The aim of the review was to investigate the relationship between physical activity level (PAL) and nutritional status (NS) in adolescents.
Methods. Seven electronic databases were searched for research from the years 2005–2015. The studies must have mentioned the relationship between PAL and NS parameters in adolescents. After the review of abstracts and articles, 22 papers meeting the required criteria were further analysed in detail.
Results. The studies included 31,045 subjects of both sexes. The results showed that smaller PAL led to an increase of NS parameters and vice versa. Comparing the total PAL, the total time spent in moderately vigorous physical activity, and the total time of vigorous PA (VPA), only VPA was a significant predictor of the responders’ percentage of fat mass. Reducing the activity by 10 MET on the weekly level was associated with an increase in BMI in girls for 0.11 kg/m2, while an increase of the activity by 1 hour per week resulted in a decline in BMI by 0.13 kg/m2.
Conclusions. Total PAL has a significant correlation with NS in adolescents. This relationship is inverse, which means that more active adolescents are less overweight than their less active and/or inactive counterparts and vice versa. In addition to PAL, the character or intensity of physical activity has a significant impact on BMI. Physical activity of higher intensity influenced the reduction of body weight and fat mass more than activity of the same duration but of moderate intensity.
Key words: inactivity, body mass index, body composition, obesity, children
Energy requirement in sports performance are affected by numerous factors: physical characteristics and age of subjects, genetic basis, kind of sport practiced. Food and Nutrition Board recommended nutrition based on age, height and body weight gain in relation to practiced physical activity. Among factors that affect metabolism some genetic factors play a key role, such as a gene encoding for PPAR.
Purpose. The aim of this study was to investigate the effect of a specific snack on the performance.
Methods. Seventeen girls aged between 10 and 14 years of pre-agonist artistic gymnastics were enrolled; we provided a carbs or a protein/carbs snack before the training and we administered a specific questionnaire at the end of it. In addition, a saliva sample was taken from each girl to carry out genetic analysis.
Results. Most of the girls had CC genotype (65%) while a small part had the GC (23%) and GG (12%); the group with CC genotype had an average BMI of 20.05 ± 2.8 kg/m2, whilst the GC genotype group had an average BMI of 19.6 ± 2.8 kg/m2 and the GG genotype of 20.2 ± 2.8 kg/m2. Concerning the questionnaire, 59% of girls have a performance improvement after they have eaten the carbs snack, whilst slightly difference was highlighted after the intake of protein/carbs snack: 47% felt more energy and 12% more fatigue.
Conclusions. This is a preliminary study that should be deepened by increasing the number of subjects involved as well as diversify the type of snacks administered and increase the time of the study; it is important to emphasize that it is necessary be mindful of eating habits and lifestyle in order to prevent the possible onset of overweight.
MATURATION-RELATED DIFFERENCES IN NEUROMUSCULAR FATIGUE AFTER A SHORT-TERM MAXIMAL RUN
SAMI ÄYRÄMÖ, NIKKE VILMI, ANTTI ANTERO MERO, JARMO PIIRAINEN, ARI NUMMELA, TEEMU PULLINEN, JANNE AVELA, VESA LINNAMO
Purpose. This study investigated maturation-related differences in neuromuscular fatigue after a short-term maximal run.
Methods. Eight male children, eight adolescents, and eight adults performed a maximal ca. 50-s run (300/350/400 m, respectively). Mechanisms of neuromuscular fatigue were assessed through isometric plantar flexor tests, electrical stimulation of the posterior tibial nerve, soleus electromyography, and blood tests.
Results. All the groups showed a decrease in the running speed (children: –12.2 ± 6.5%; adolescents: –9.8 ± 5.1%; adults: –12.2 ± 3.1%), but only adults revealed a decline in the maximal isometric plantar flexor torque (–16.1 ± 13.0%). On the other hand, the relative pre- to post-fatigue change in the maximal isometric plantar flexor torque differed only between adults and adolescents. The peak torque in the passive twitch test decreased in adolescents (–19.2 ± 12.2%) and adults (–23.7 ± 13.7%). Moreover, post-fatigue minimum blood pH (children: 7.18 ± 0.03; adolescents: 7.14 ± 0.07; adults: 6.97 ± 0.06) differed between the groups. No changes were observed in the neural drive or mechanisms at the spinal level.
Conclusions. Despite the loss of running speed, children showed no post-exercise fatigue, whereas adolescents and adults demonstrated fatigue at peripheral sites. Central fatigue could not be established for the studied groups.
SEX DIFFERENCES IN FRONTAL AND TRANSVERSE PLANE HIP AND KNEE KINEMATICS DURING THE MODIFIED STAR EXCURSION BALANCE TEST
BRAD W. WILLIS, SWITHIN RAZU, KELLI BAGGETT, AMIRHOSSEIN JAHANDAR, AARON D. GRAY, MARJORIE SKUBIC, SETH L. SHERMAN, KYLE BLECHA, TRENT M. GUESS
Purpose. The modified Star Excursion Balance Test (mSEBT) assesses dynamic neuromuscular control, with predictive ability regarding lower extremity injury risk. Previous kinematic mSEBT analyses are limited to sex differences between injured or fatigued populations or non-fatigued groups in the sagittal plane only. We hypothesize that sex differences exist in the frontal and transverse plane kinematics of the hip and knee in healthy, non-fatigued subjects during the mSEBT.
Methods. The descriptive laboratory study involved 38 healthy subjects: 20 males (aged 24.8 ± 2.7 years) and 18 females (24.1 ± 3.7 years). Peak kinematics, obtained by a VICONTM motion system, of the hip and knee in the sagittal, frontal, and transverse plane were compared during the anterior, posteromedial, and posterolateral reach of the mSEBT. Wilcoxon rank test with significant differences at p < 0.05 was used.
Results. Kinematic differences existed between the groups in the frontal and transverse plane of the hip and knee in all reach directions (p < 0.05). No differences were found in the sagittal plane of the hip or knee between the groups.
Conclusions. Sex differences exist in frontal and transverse plane kinematics of the hip and knee during the mSEBT. The mSEBT may be enhanced as an injury prediction tool, if frontal and transverse plane kinematics were included during risk assessment screening.
A COMPARISON OF ISOKINETIC KNEE STRENGTH AND POWER OUTPUT RATIOS BETWEEN FEMALE BASKETBALL AND VOLLEYBALL PLAYERS
JAROSŁAW KABACIŃSKI, MICHAŁ MURAWA, ANNA FRYZOWICZ, LECHOSŁAW BOGDAN DWORAK
Purpose. Tests such as the counter movement jump (CMJ) and squat jump (SJ) allow for determining the ratio of maximal
power output generated during SJ to CMJ (S/C). The isokinetic peak torque ratio of the hamstrings contracting eccentrically to
the quadriceps contracting concentrically (H/Q) is defined as functional H/Q. The purpose of this study was to compare the S/C
and functional H/Q between female basketball and volleyball players.
Methods. The total of 14 female basketball players (age, 19.8 ± 1.4 years) and 12 female volleyball players (age, 22.3 ± 4.2 years)
participated in the study. A piezoelectric force platform was used for the CMJ and SJ. Moreover, isokinetic tests of the hamstrings
and quadriceps muscle torque during eccentric and concentric contraction were performed.
Results. The results of the S/C and functional H/Q at 90 deg · s–1/60 deg · s–1 velocities were higher in basketball players (87.3 ±
9.1% and 91.4 ± 9.3%, respectively) than in volleyball players (83.1 ± 9.8% and 83.6 ± 16.5%, respectively). No significant differences in S/C or functional H/Q values between the two groups were found (p > 0.05).
Conclusions. Decreasing the S/C may result from an improvement in the power output during CMJ and a better utilization of
the stretch-shortening cycle effect. Balancing the functional H/Q through increasing the eccentric hamstrings strength can
provide dynamic knee joint stabilization.
Key words: muscle strength, power output, vertical jumps, basketball, volleyball
EFFECTS OF AN EIGHT-WEEK STEPLADDER EXERCISE PROTOCOL ON LOWER LIMB MUSCULAR STRENGTH OF APPARENTLY HEALTHY YOUNG ADULTS
OLADAPO MICHAEL OLAGBEGI, BABATUNDE OLUSOLA ADEGOKE, CANDICE JO-ANNE CHRISTIE, OLUFEMI SAMUEL BOLARINDE, JOSEPH ADEIZA JEGEDE
Purpose. Backward descent of stairs is associated with improved muscle strength and reduced joint stress, but the effect of backward ascent of stairs on lower limb muscle strength has not been reported. This study compared the effects of forward and backward stair climbing on lower limb muscle strength in apparently healthy young adults.
Methods. The total of 31 young volunteers were allocated to either forward or backward stair climbing group (n = 16 and 15, respectively). Dynamic quadriceps and hamstring muscle strength was assessed in addition to thigh girth at baseline and at weeks 4 and 8 with the use of the repetitive maximum method and tape measure, respectively.
Results. Between baseline and week 8, muscular strength in both groups (quadriceps: 14.4 ± 3.6 to 16.4 ± 3.4 kg; 14.0 ± 2.9 to 15.3 ± 2.7 kg; hamstring: 12.2 ± 3.2 to 13.4 ± 3.2; 11.7 ± 2.5 to 12.9 ± 2.7 kg) increased significantly (p < 0.05) while the increase in thigh girth was not significant (p > 0.05). The groups were comparable in all three measures post intervention.
Conclusions. Forward and backward stair climbing protocols are effective for improving the dynamic strength of the hamstring and quadriceps muscles of apparently healthy young adults. Thus, either protocol could be used for the improvement of lower limbs dynamic muscle strength.
Physical activity of female students in secondary schools from the aspect of physical activity recommendations fulfilment
Ján Junger, Peter Kačúr, Lenka Tlučáková, Pavol Čech, Viera Bebčáková
Increasing energy intake and decreasing movement performance constitutes manifestly but mainly latently one of the greatest population issues of mankind. More experts focus on the issue, clearer can be defined the way of its elimination. The elimination consists in returning of physically active way of life. The best period to start finding and offering appropriate solutions is in childhood and continue through adolescent period. What we need are serious analyses of movement regimes of all age categories.
Purpose. The aim of the paper was to analyse physical activity of female of selected secondary schools in Presov district region from the aspect of physical activity recommendations fulfilment.
Methods. Research group consisted of 353 female students from 14 selected secondary schools in Presov district region. Students were distributed in four groups according to age from 15 to 18 years old.
Results. More than a half of 15-18 years old female students did not perform movement activity of medium or high intensity. The highest percentage of success rate in criteria fulfilment achieved female of all age categories in walking 5 times per week minimally 30 minutes (W 5x30). Only 44.3% of female at the age of 15 and up to 70.8 % at the age of 18 met at least one criterion of physical activity recommendations.
Conclusions. From the aspect of physical activity recommendations fulfilment, the most successful criterion was performing physical activity regardless its intensity. Physical activity recommendations seem to be very hard to achieve in the age category, mainly in physical activity intensity.
Key words: Physical Activity Intensity, IPAQ, adolescents, health