Sub-maximal blood lactate assessment of professional youth soccer players throughout the soccer season

McMillan, Kenneth (2002) Sub-maximal blood lactate assessment of professional youth soccer players throughout the soccer season. MSc(R) thesis, University of Glasgow.

Abstract

Aerobic fitness is recognised as a very important fitness component in soccer (Reilly, 1994, Science and Soccer. E&FN Spon, UK). Thus, it is of importance to monitor the aerobic fitness of professional soccer players periodically throughout the soccer season. The aim of this study was to examine the changes in aerobic fitness of professional youth soccer players from the pre-season period to the start of the competitive season and throughout the competitive season. Thirty-seven male professional youth soccer players aged (mean +/- sd) 18.9 +/- 1.8 years participated in this study. The players were tested at six time-points throughout the playing season - sub-maximal running was performed on a treadmill (Woodway Ergo ES2, Cranlea, UK) and consisted of at least six progressive four-minute stages. Fingertip blood samples were collected at the end of each running speed and analysed for whole blood lactate concentration using an Analox GM7 analyser (Analox Instruments, UK). Although 37 soccer players participated in this study, not all players were tested at each time point (Table A), in order to account for the within-subjects design and the fact that there are missing data at certain testing time-points (which is assumed to be missing at random), a Repeated Measures Analysis of Variance with Bonferroni Multiple comparisons, and Bonferroni adjusted paired t-tests were used to determine any significant changes in aerobic fitness, using running speeds at the lactate threshold [vLT] and 4 mmol.l-1 [vLac4]. Aerobic fitness increased from the start of pre-season training to October (5 weeks into the competitive season) as evidenced by an increase in mean vLT and mean vLac4 (p<0.001) (Table 1). The mean vLT was highest in December (p<0.001) compared with January and June. Other fluctuations in the mean vLT throughout the competitive playing season were found to be non-significant. No significant differences in mean vLac4 were found during the competitive season. In conclusion, aerobic fitness increased from the start of pre-season training to the early weeks of the competitive playing season. The mean vLT was found to be highest in December. These findings demonstrate that the pre-season training was effective in improving aerobic fitness. The feet that the January, April and June vLT scores were lower than those in December suggests that coaches should examine the aerobic training regimens in the second half of the season. Table A. Lactate threshold (vLT) and 4 mmol.l (vLac4) running velocity (mean +/- sd) and number of observations for each testing time-point a - significantly higher than pre-season (p<0.001) b - significantly higher than January and June vLT (p<0.001).

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Kinesiology.
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Grant, Dr. Stan
• Date of Award: 2002
• Depositing User: Enlighten Team
• Unique ID: glathesis:2002-73235
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 01 Sep 2022 13:46
• Thesis DOI: 10.5525/gla.thesis.73235
• URI: https://theses.gla.ac.uk/id/eprint/73235