RESEARCH EXERCISE SCIENCESPORT EXERCISE SCIENCE

BY KYLE BENNETT AND CLARE PHEASEY, DEPARTMENT OF EXERCISE AND SPORT SCIENCE, MANCHESTER METROPOLITAN UNIVERSITY

INTRODUCTION A high capacity to take in and utilise oxygen (maximal oxygen uptake, VO2max) and a high lactate threshold (LT) are considered to be the most important physiological determinants of success in both middle- and long-distance running performance (1). Crash training (CT) is a method of training conducted over a relatively short period of time (3–7 days) during which a 100% increase in training volume and high-intensity sessions are prescribed. The increase in physiological stress experienced during CT provides a greater training stimulus than that experienced during “normal” training. It is believed that CT specifically facilitates an increase in VO2max.

PURPOSE To investigate the effect of a CT protocol on both VO2max and LT.

METHODS n Following ethical approval, eight middle-distance runners (mean±standard deviation (SD): age 16.4±1.2 years; stature 1.71±0.07m; body mass 60.7±7.6kg) gave informed consent to participate in the study. n Participants were divided into two groups, CT and control (CONT). n The CT group followed a CT protocol for a period of 5 days, followed by 5 days of reduced training (50% of the normal weekly training mileage) and 14 days of normal training, before repeating the CT protocol for a second time. During this time participants in the CONT group continued to train normally. n Training diaries were completed daily throughout the intervention, providing a daily record of training performed. n Participants completed treadmill tests pre- and post- intervention to ascertain LT and VO2max. Whole blood was analysed to obtain lactate concentration. Heart rate (measured at 60-s intervals), rate of perceived exertion (RPE) and expired air data were recorded in accordance with established protocols.

DATA ANALYSIS Following appropriate checks on underlying assumptions, a two-way (mixed) analysis of variance (ANOVA) was used to determine significant differences between the dependent variables.

KEY FINDINGS n Mean VO2max increased significantly in the CT group (68.3 to 71.9ml.kg-1.min-1, P=0.0003) compared with the CONT group (68.4 to 68.6ml.kg-1.min-1, P=0.2946). n In comparison, no change in mean LT was observed in the CT group (11.8km.h-1), while a small but insignificant

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THE EFFECT OF A CRASH TRAINING PROTOCOL ON MAXIMAL OXYGEN UPTAKE AND LACTATE THRESHOLD IN MIDDLE-DISTANCE RUNNERS

(P=0.0908) increase was observed within the CONT group (11.3 to 11.8km.h-1). n It was also noted that time to fatigue (VO2max test) increased significantly (626 to 697 s, P=0.0065) in the CT group, but no significance (P=0.0701) was found in the CONT group (598 to 608 s).

CONCLUSION

Participating in a CT protocol can significantly increase VO2max in middle-distance runners. Future research could look at the CT protocol in more detail, investigating the effects of the number of CT cycles with a view to identifying an optimum, any potential overtraining risks with repeated use of the CT protocol, and also any benefits with athletes participating in more training at the LT to try to improve this.

Reference 1. Brandon LJ. Physiological factors associated with middle distance running performance. Sports Medicine 1995;19:268–277.

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