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Intervention programs used regarding postural deviations among children (Review article)
A prospective controlled study of exercises for the improvement of posture]. 2005. 58 (5-6): P. 177-82.
12. Geldhof E., Cardon G., Bourdeaudhuij I & Clercq D. Back posture education in elementary schoolchildren: stability of two-year intervention effects. Eura Medicophys. 2007. 43 (3): P. 369-79.
Selenica Rigerta, Sports University of Tirana, Albania PhD student in Sport Science Faculty of Movement Science E-mail: rigertameta@hotmail.com Enkeleda Lleshi, Sports University of Tirana Scientific Research Institute of Sport. PhD student in Sport Science
The impact of strength training in VO2 performance (Stady Case)
Abstract: In volleyball the main achievement is winning the match so the means and methods used during the training sessions are very important to achieve this goal. The purpose of our study case is to show the impact of a method of strength training on the development performance of the maximum VO2. Methodology: Ästrand Bike Test has been used to assess the VO2 max. The study included 20 female volleyball players at the average age 17.5, who were divided in two groups called Team_and Control Group. The first group, the Team, apart from the volleyball training program, was simultaneously trained with exercises of strength, two times per week along a period of 12 weeks. Both groups were tested before the training by means of Pre-Test. After 12 weeks both groups, the Team and Control Group, underwent testing through the Post test. The processing of the results is carried out on the bases of the group mean. Results were processed statistically with Wilcoxon Signed — Rank test calculator and Pearson correlations calculator.
Results: Results showed a positive progress value from the Pre-test to Post-test, for both the Team and the Control Group: the result is significant at p<0.05 to Max 02ptake 1/min and Max 02 Uptake Ml/kg/min. Results showed correlations between Max heart rate bpm and Max 02 Uptake 1/min, Max heart rate bpm and Max 02 Uptake Ml/kg/min on post test for the Team, that showed negative correlation, but the results are not significant at p<0.05. Comparison of pre and post test results for the Control Group did not mark a significant value to p<0.05 for Max 02ptake1/min and Max 02 uptake Ml/kg/min.Conclusions and discussions: Strength training has made the single, most positive contribution to this type of improvement. Strength training influences every sport program, no matter what the sport is. We must remember that strength builds the foundation for all other physical qualities. Our study shows that the correlation between strength training and performance improvement of VO2 max results of laboratory values compared to the good part of them were significant. Important for our study was the transfer of improving the performance of force training to the component of The VO2max, which is an important component of influencing the sports results. Strength training impact cannot say that is a key indicator but secondary indicator on VO2max performance. Referring to the results, performance VO2max more influenced by the beat of the heart which leads us to and exercise of force should be adequately regulated on the range of heart rate always working in areas where the impact to be higher.
Keywords: strength training, VO2 max, volleyball, performance.
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Section 7. Physical Education
Introduction:
Performance in sports is essential for any discipline. Likewise, in volleyball the main objective is good performance on the match day, and the achievement of this goal is greatly denedent on the means and methods used during the training sessions. The purpose of our study is to show the impact of strength training on the performance of VO2 max. Cardiovascular capacity has often been thought to be the main limiting factor in endurance performance. Classical measures such as maximal oxygen uptake (VO2 max) and lactate threshold (LT) have been traditionally used in the laboratory to predict the performance potential [1,70-84] Consequently, the physical preparation for these sports is generally focused on the development of the physiological quality. However, elite endurance athletes with similar levels of VO2 max can have different abilities during a match and therefore maximum oxygen uptake can not fully explain the true ability at matches. Efficiency, and assessments that include a power component spe-
cific muscle endurance, such as speed/power during maximal oxygen uptake (VO2max)), now thought to be superior performance indicators in a sporting elite [14, 286-91]. Economy is the amount of metabolic energy expended at a given velocity or power output [5, 316-9]. Economical movement is multifactorial and is determined by training history, anthropomet-rics, biomechanics and physiology [7, 1918-22] during Improvements in economy may be difficult to obtain in highly-trained endurance athletes and therefore any novel training modality that results in marginal improvements may be crucial for success. Endurance-specific muscle power is the ability of the neuromuscular system to rapidly produce force following a sustained period of high-intensity exercise (high glycolytic and/or oxidative energy demand) [15, 1527-33]. This ability may be the differentiating factor for elite endurance performance as successful athletes at world level can produce high elocities and power outputs to win a race following a sustained period of high-intensity exercise (figure 1).
Figure.1 Hypothetical model of the determinants for elite endurance performance and the potential benefits from strength training [3, 845-865]
Economy is represented by energy expenditure and is normally expressed as submaximal VO2 at a given velocity or power output. It is now established that economy is a critical factor for success in elite sport [18, 465-85]. The present research shows that there were significant improvements in economy from both maximal- and reactive-strength training interventions [10, 224-9] [2, 1818-25]. This supports Noakes’ philosophy [13, 19-21] that performance with poor economy may lack musculo-
tendinous stiffness and therefore strength training may improve the ability of the leg musculature to rapidly absorb and utilize the elastic energy produced during each ground contact.
Endurance-specific muscle power is the ability of the neuromuscular system to rapidly produce force following a sustained period of high-intensity exercise (high glycolytic and/or oxidative energy demand) [15, 1527-33]. This combined neuromuscular and anaerobic ability may be the differentiating factor for
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The impact of strength training in VO2 performance (Stady Case)
elite endurance performance as successful athletes at world-level can produce high velocities and power outputs to win a race following a sustained period of high intensity exercise [15, 1527-33].
Recent research suggests that strength training is one of the most powerful interventions to improve sports results as an indicator of physical quality improvement [9, 870-877; 19, 1087-1092]. Muscular hypertrophy has been shown to interfere with some peripheral aerobic adaptations, [12, 164-166] it has been suggested that implementations should use strength training methods that emphasize on neural adaptations [4, 385-394].
Plyometric and dynamic weight training (PT and DWT) fulfill this requirement. Plyometric training involves an eccentric contraction immediately followed by a concentric contraction to allow the muscle to store and recoil elastic energy [8, 587-600].Jumps and rebounds are typically used to induce this muscle stretch shortening cycle. Dynamic weight training involves concentric contractions leading to the maximal power output. It generally consists in moving relatively light loads (between 30 and 50% of 1 repetition maximum) as fast as possible [20, 1279-1286].
Methodology: the two known tests for the assessment ofVO2 max are Ästrand Bike Test and the Harvard Step Test. These tests are based on the linear relationship between heart rate (HR) and VO2. Indicator in increased heart beat is the intensity rate which translated the values ofVO2 [11, 19-69].
The Ästrand Bike Test (also known as the Ästrand-Ryhming test) was first developed by P. O. Ästrand in 1956. It is a 6 minute test that uses a cycle ergo meter (a fixed exercise bike), can be used in both men and women of various ages and relies on the linear relationship between heart rate and VO2, as described above to predict maxVO2. The test enjoys a ± 15%
standard deviation from a directly measured max-VO2 [6, 61-582].We also included 20 female volleyball athletes with an average age 17.5, who were divided in the two groups called the Team and the Control Group. Both groups, the Team and Control Group were in the volleyball training stage. The Team beside the volleyball training program underwent exercises ofstrength, two times per week along a period of 12 weeks. Subjects completed questionnaires on their medical history and were considered healthy before starting the training. Both groups were tested before the start of the training, through the Pre Test. The groups underwent testing through the Post test after 12 weeks. Results are processed on the bases of group mean, for both Team, Control Group.
Results were processed statistically with Wil-coxon Signed — Rank test calculator and Pearson correlations calculator.
Results:
Results for the Team pre and post were taken and expressed in the average, standard deviations: Pre-Test Accept. Heart rate bpm 149.8, SD 10.2/Post-Test 150.8, SD 9.04. Pre-Test Max heart rate bpm 203.3, SD 0.8/Post-Test 203.3, SD 1.1. PreTest Vo2 correlation factor 1.04, SD 0.006/Post-Test 1.04, SD 0.006. Pre-Test Max 02 Uptake 1/min 2.65, SD 0.55/Post- Test Max 02 Uptake 1/min 2.86, SD
0.4. Pre-Test Max 02 Uptake Ml/kg/min 35.14, SD 5.6/Post-Test Max 02 Uptake Ml/kg/min37.67, SD 4.19: Results for the Team group showed positive values when pre and post tests results were compared, which are: the result is significant at p<0.05 to Max 02ptake 1/min and Max 02 Uptake Ml/kg/min.
Results showed correlations between Max heart rate bpm and Max 02 Uptake 1/min, Max heart rate bpm and Max 02 Uptake Ml/kg/min on post test for the Team, that showed negative correlation, but the results are not significant at p<0.05 (table1).
Table 1. - VO2 max PRE and POST test for Team time work 6 min, test work 450 F + 750M
No Groups Age (year) VO2 TEST Accept. heart rate bpm Max heart rate bpm Vo2 correlation factor Max 02 Uptake 1/min Max 02 Uptake Ml/kg/min
10 Team SD 1996.5 Pre- Test 149.8 203.3 1.04 2.65 35.14
10.2 0.8 0.006 0.55 5.6
10 Team SD 1996.5 Post- Test 150.8 203.3 1.04 2.86 37.67
9.04 1.1 0.006 0.45 4.19
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Section 7. Physical Education
Result for the Control Group of Pre and Post Test are shown in average and standard deviations: Pre-Test Accept. Heart rate bpm 147.6, SD 7.98/Post-Test Accept. Heart rate bpm 147.6, SD 7.98. Pre-test Max heart rate bpm 203.2, SD 0.91/Post-test Max heart rate bpm 203.2, SD 0.91. Pre-test Vo2 correlation factor 1.047, SD 0.006/Post-test Vo2 correlation factor 1.047, SD 0.006. Pre-test Max 02 Uptake Ml/kg/min 35.055, SD 4.19/Post-test Max 02 Uptake 35.043, SD 4.19.
Comparison of pre and post test results for the Control Group did not indicate any significant values, to p<0.05 for Max 02ptake1/min and Max 02 uptake Ml/kg/min.
Results showed correlations between Max heart rate bpm and Max 02 Uptake 1/min, Max heart rate bpm and Max 02 Uptake Ml/kg/min on post test for the Control Group, that showed negative correlation, but the results are not significant at p<0.05 (table 2).
Table 2. - VO2 max PRE and POST test for Control Group with work time 6 min, test work 450 F+ 750M
No Groups Age (year) VO2 TEST Accept.heart rate bpm Max heart rate bpm Vo2 correlation factor Max 02 Uptake 1/min Max 02 Uptake Ml/kg/min
10 Control Group SD 1996.4 Pre-Test 147.6 7.98 203.2 0.91 1.047 0.006 2.542 0.30 35.055 4.19
10 Control Group SD 1996.4 Post-Test 147.6 7.98 203.2 0.91 1.047 0.006 2.538 0.31 35.043 4.19
Results compared to post test between the 1/min, expressed minor but significant differences Team and the Control Group for Max 02 Uptake at p<0.05. (table3, 4)
Table 3. - Summary of VO2 max PRE - TEST Team and Control Group with work time 6 min, test work 450 F + 750M
No Groups Age (year) VO2 TEST Accept.heart rate bpm Max heart rate bpm Vo2 correlation factor Max 02 Uptake 1/min Max 02 Uptake Ml/kg/min
10 Control Group SD 1996.4 Pre-Test 147.6 7.98 203.2 0.91 1.047 0.006 2.542 0.30 35.055 4.19
10 Team SD 1996.5 Pre-Test 149.8 10.2 203.3 0.8 1.04 0.006 2.65 0.55 35.14 5.6
Table 4. - Summary of VO2 max POST-TEST Team and Control Group with work time 6 min, test work 450 F + 750M
No Groups Age (year) VO2 TEST Accept.heart rate bpm Max heart rate bpm Vo2 correlation factor Max 02 Uptake 1/min Max 02 Uptake Ml/kg/min
10 Control Group SD 1996.4 Post-Test 147.6 7.98 203.2 0.91 1.047 0.006 2.538 0.31 35.043 4.19
10 Team SD 1996.5 Post-Test 150.8 9.04 203.3 1.1 1.04 0.006 2.86 0.45 37.67 4.19
Results of post test compared between the Conclusions and discussions:
Team and the Control Group for Max 02 Uptake Strength training has made the single, most
Ml/kg/min showed no significant values at positive contribution to this type of improvement. p<0.05. Strength training influences every sport program,
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The impact of strength training in VO2 performance (Stady Case)
no matter what the sport is. We must remember that strength builds the foundation for ALL other physical qualities. According to the comparison of results of laboratory values for the pre and post tests it is pointed out, for the maj ority ofthem, a significant improvement on performance as well as a strong correlation between strength training and VO2 max. These results showed that the improvement value was minor compared with the Control Group and Team. Results were not significant at p<0.05. Important for our study was the transfer of strength performance onto VO2max indicators, which is an essential component that influences sports results. Comparison of results on pre and post test ofMax 02 Uptake1/min between Team and Control Group was significant at p<0.05. Value of Max 02 Uptake Ml/kg/min would be better assessed if body weight could be included. Studies have shown correlations between body weight and VO . Results showed correlation between maximal heart rate and Max 02 Uptakel/min, Max 02 Uptake Ml/kg/min. Based on these results we can say that introduction of the strength training programs at volleyball season matches we will
not lower the performance of VO2max. Strength training impact cannot imply that it is a key indicator but more a secondary one on VO2max performance. Referring to the results, VO2max performance is more influenced by the heart rate which leads us to the fact that strength exercises should be adequately regulated on the range of heart rate which on the other hand will increase the VO2max performance with a high intensity workload and a certain duration which increase heart rate and affect transfer capacity of VO2max.
Further implications:
Our study on the Impact of strength training in VO2 performance will continue even further by focusing on the rating of Force training in the range of heart rate or to the drill of sustainability of strength to see its effect on VO2max. In this study we focused only on Uptake ratios Max 02 l/min and Max Uptake 02 ml/kg/min, maximum heart rate. In successive studies we should introduce more indications to shed light on the development of strength training reports on VO2max indicators.
References:
1. Bassett, D. R., & Howley, E. T. (2000). Limiting factors for maximum oxygen uptake and determinants of endurance performance. Med Sci Sports Exerc.;32 (l): 70-84.
2. Berryman, N., Maurel, D., Bosquet, L. (2010). Effect of plyometric vs. dynamic weight training on the energy cost of running. J Strength Cond Res.;24 (7): 1818-25.
3. Beattie, K., Kenny, C. I., Lyons, M., Carson, P. B. (2014). The Effect of Strength Training on Performance in Endurance Athletes. Sports Med 44:845-865 DOI 10.1007/s40279-014-0157-y.
4. Docherty, D.,& Sporer, B. (2000). A proposed model for examining the interference phenomenon between concurrent aerobic and strength training. Sports Med 30: 385-394.
5. Foster, C., Lucia, A. (2007). Running economy: the forgotten factor in elite performance. Sports Med.;37 (4-5): 316-9.
6. Foss, M. L., & Keteyian, S. J. (1998). Fox’s Physiological Basis for Exercise and Sport,, 6th ed., McGraw-Hill International. P. 61-582.
7. Fletcher, J. R., Esau, S. P., MacIntosh, B. R. (2009). Economy of running: beyond the measurement of oxygen uptake. J Appl Physiol.;107:1918-22.
8. Hakkinen, K., Komi, P. V., and Alen, M. (1985). Effect of explosive type strength training on isometric force- and relaxation-time, electromyographic and muscle fibre characteristics of leg extensor muscles. Acta Physiol Scand 125: 587-600.
9. Hoff, J., Helgerud, J., and Wisloff, U. (1999). Maximal strength traiing improves work economy in trained female cross-country skiers. Med Sci Sports Exer 31: 870-877.
10. Johnston, R. E., Quinn, T. J., Kertzer, R., et al. (1997). Strength training in female distance runners: impact on running economy. J Strength Cond Res.;11 (4):224-9.
11. Maud, P. J., & Foster, C. (1995)., Physiological Assessment of Human Fitness. P. 19-69.
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12. MacDougall, J. D., Sale, D. G., Moroz, J. R., Elder, G. C. B., Sutton, J. R., and Howald, H. (1979). Mitochondrial volume density in human skeletal muscle following heavy resistance training. Med Sci Sports Exerc 11: 164-166.
13. Noakes, T. D. (2003). Lore of running. 4th ed. Champaign: Human kinetics. P. 19-21.
14. Paavolainen, L., Nummela, A., Rusko, H. (2000). Muscle power factors and VO2max as determinants of horizontal and uphill running performance. Scand J Med Sci Sports.; 10: 286-91.
15. Paavolainen, L., Hakkinen, K., Hamalainen, I., et al. (1999). Explosive strength training improves 5-km running time by improving running economy and muscle power. J Appl Physiol.; 86: 1527-33.
16. Paavolainen, L., Hakkinen, K., Hamalainen, I., et al. (1999). Explosive strength training improves 5-km running time by improving running economy and muscle power. J Appl Physiol.;86: 1527-33.
17. Paavolainen, L. M., Nummela, A. T., Rusk, H. K. (1999). Neuromuscular characteristics and muscle power as determinants of 5 km running performance. Med Sci Sports Exerc.; 31:124-30.
18. Saunders, P. U., Pyne, D. B., Telford, R. D., et al. (2004). Factors affecting running economy in trained distance runners. Sports Med.; 34 (7): 465-85.
19. Storen, O., Helgerud, J., Stoa, E. M., and Hoff, J. (2008). Maximal strength training improves running economy in distance runners. Med Sci Sports Exerc 40: 1087-1092.
20. Wilson, G. J., Newton, R. U., Murphy, A.J., and Humphries, B. J. (1993). The optimal training load for the development of dynamic athletic performance. Med Sci Sports Exerc 25: 1279-1286.
Spahiu Elton, Erindi Altin, QeleshiAnesti, Sports University of Tirana PhD student at Sport Sciences E-mail: eltonsph@yahoo.it
Relationship between diet and body fitness, with adjustment for resting energy expenditure and physical activity
Abstract:
Introduction: Research efforts for effective treatment strategies still focus on diet and exercise programs, the individual components of which have been investigated in intervention trials in order to determine the most effective recommendations for sustained changes in bodyweight. Obesity, particularly central adiposity, has been increasingly cited as a major health issue in recent decades. Indeed, some of the leading causes of preventable death and disability, including heart disease, stroke, type 2 diabetes, degenerative joint disease, low back pain, and specific types of cancer are obesity-related [1, 104-108]. Annual obesity-related medical costs in the United States were estimated to be as high as $147 billion in 2009 [3, 822-831].
Experimental design: A total of 70 recreationally active males and females between the ages of 15 and 18 years were recruited to participate in the study. In this study, recreationally active was defined as participating in less than or equal to two exercise sessions per week over the previous 30days. Subjects were required to have a body mass index (BMI) greater than 27kg/m 2 and body fat greater than 20% (for males) or greater than 25% (for females). This study utilized a randomized, placebocontrolled, parallel-group, double-blind design. Subjects were matched according to sex and BMI prior to being randomized into different groups based on the physical activity patterns.
Conclusions: Basal metabolism is lower in people that have a lower physical activity based on the fact that they have a lower muscle mass. Basal metabolism is higher in the moderate physical activ-
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