european college of sport science

OP-PH15 Physiology 15
Conclusion
The biological maturity status significantly influences the functional capacity and athletic performance (speed and aerobic endurance)
and highlights the inter-relationship of growth, maturity and functional characteristics of youth soccer players. The lack of further improvements
in aerobic endurance capacity and sprint abilities of soccer players being 16 yrs and older detected in this study underlines
the importance of continuing and improving the proportion of athletic training in adult soccer players.
15:15 - 16:45
Oral presentations
OP-PH15 Physiology 15
HIGH INTENSITY SHOCK MICROCYCLES: AN EFFICIENT METHOD FOR IMPROVING VO2MAX IN JUNIOR ALPINE SKIERS
BREIL, F.A., WEBER, S.N., KOLLER, S., HOPPELER, H., VOGT, M.
1 INSTITUTE OF ANATOMY, UNIVERSITY OF BERN, SWITZERLAND, 2 INSTITUTE OF HUMAN MOVEMENT SCIENCES AND SPORT, SWISS FEDERAL
INSTITUTE OF TECHNOLOGY ZURICH, SWITZERLAND, 3 INSTITUTE OF SPORT AND SPORT SCI
Introduction: Maximal oxygen consumption (VO2max) is often used to predict aerobic endurance capacity. In already-trained soccer
players, VO2max can be further improved by performing high-intensity interval training (HIT) sessions twice a week over two months
(Helgerud et al., 2001). Alternatively, it seems that VO2max can effectively be increased when HIT sessions are performed once or twice
daily within a condensed 10-day shock microcycle (Stolen et al., 2005). Such a concept could be particularly useful for athletes who cannot
afford the time for extensive endurance training due to high technical and strength demands of their sport. The aim of our study was
to investigate the effect of an 11-day high-intensity shock microcycle on endurance and jump performance in junior alpine skiers.
Methods: Six female and sixteen male subjects (age: 17.0 ± 1.1 yr, body mass: 67.3 ± 10.4 kg) were matched and randomly assigned to
either a high-intensity interval training group (HIT, N = 13) or a control training group (CON, N = 8). HIT performed 15 HIT-sessions (12 on a
cycle ergometer, 3 on an obstacle course) during 11 days. Each session consisted of 4×4 min at 90-95% of the individual maximal heart
rate (HRmax), separated by 3-min recovery periods. CON continued their normal mixed training including endurance and strength sessions.
Before, 24 hours and seven days after the training period, anthropometric data were gathered and ramp tests to exhaustion on a
cycle ergometer were performed to determine HRmax, VO2max, peak power output (PPO) and the first and second ventilatory thresholds
(VT1, VT2). At the same time-points, countermovement and squat jumps were performed on a force plate.
Results and discussion: Body mass and fat-free mass were reduced in HIT only (-1.0%,-1.1% (P < 0.05), respectively). Seven days postintervention
HIT significantly improved VO2max by 6.0% (pre: 53.0 ± 4.6, post: 56.2 ± 5.1 mL•kg-1•min-1; P < 0.01) and PPO by 4.4% (pre:
5.2 ± 0.4, post: 5.5 ± 0.5 W•kg-1; P < 0.01). CON showed slight but nonsignificant improvements in VO2max (+3.0%) and PPO (+2.0%).
Power output at VT2 increased in HIT by 9.6% (P < 0.01), but not in CON, whereas jump height was unchanged in both groups. In the HITgroup
the described functional improvements were already present but to a lesser extent in the post 24-hours measurements.
Our results show that high-intensity interval block training might be a very time efficient way to improve VO2max, PPO, and the power
output at VT2 in junior alpine skiers. Accumulated fatigue of such an intense training cycle seems to delay the development of the functional
adaptations. Therefore, athletes and coaches should plan rest-days to ensure adequate recovery and maximal training effect.
- Helgerud J. et al., 2001; Med Sci Sports Exerc 33(11): 1925-31
- Stolen T. et al., 2005; Sports Med 35(6): 501-536
ACTIVE OR PASSIVE - THE INFLUENCE OF TWO DIFFERENT REST PROTOCOLS ON POWER OUTPUT, LACTATE AND PH
TIME COURSE AND PEAK OXYGEN UPTAKE DURING HIGH INTENSITY TRAINING
HAEGELE, M., ZINNER, C., WAHL, P., SPERLICH, B., MESTER, J.
GERMAN SPORT UNIVERSITY COLOGNE
Introduction: During past years much scientific effort has been undertaken to observe the effects of high intensity training (HIT) on endurance
performance. Although many studies used varying intensities during the exercise bouts, much less data exists describing how the
recovery periods between the intense bouts should be realized. To answer this question, the role of lactate and hence pH has to be
considered, since the accumulating lactate during passive recovery is still often considered as major parameter causing muscle fatigue.
Latest scientific research reports by contrast that lactate acts as energy reservoir and signal molecule. Due to these findings, the aim of
this study was to compare the effects of two different rest protocols power output and physiological parameters.
Methods: 12 male endurance athletes (age: 24,4 ± 3,9 years, height: 183,9 ± 4,6 cm, weight: 76,2 ± 7,2 kg) completed two testing sessions
on a cycle ergometer. Each testing session consisted of a 10min warm up at 2 Watt/kg followed by four 30sec maximal sprints. The
10min recovery periods between the sprints were either active (ACT, cycling at 1,5 Watt/kg) or completely passive (PAS), which was assigned
randomly. Peak Power (PP) and Mean Power (MP) were detected for each sprint. During the recovery intervals capillary blood was
used to detect lactate concentrations (Lac) at 0, 1, 3, 5, 7 and 9min. Furthermore pH was measured at 2, 6 and 9min, whereas oxygen
uptake (V02peak) was observed during the whole training session.
Results: MP was 749 ± 120, 741 ± 122, 720 ± 120 and 709 ± 108 Watt for ACT and 740 ± 109, 712 ± 91, 660 ± 90 and 653 ± 93 Watt for
PAS. The difference between the two recovery protocols reached statistical significance at the 3rd & 4th bout. Lac were similar 0, 1, 3 and
5min after the first bout but the concentrations in ACT decreased significantly from 7min and remained lower for all following points of
measurement. pH differed significantly from 9min after the second bout, showing higher values for ACT. Analysis of spirometric data
revealed no statistical difference for VO2peak during the bouts.
Conclusion: Our study revealed that the active recovery protocol was more sufficient to sustain power output over four consecutive maximal
bouts. Furthermore it can be speculated if an active recovery process allows an athlete to perform more intense intervals in a row.
Anyhow, dependent on the aim of a training intervention one should consider possible differences in metabolic stimuli due to different
recovery protocols and resulting lactate concentrations as well as acid-base balances. Several studies provide evidence for an impact of
acidosis and lactate on growth hormones and transcription factors which would favor passive recovery protocols due to greater physio-
274 14 TH
ANNUAL CONGRESS OF THE EUROPEAN COLLEGE OF SPORT SCIENCE