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This Article Full Text Full Text (PDF) All Versions of this Article: jas.2009-2001v1 87/10/3211    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Lindner, A. Articles by Sallmann, H. P. PubMed PubMed Citation Articles by Lindner, A. Articles by Sallmann, H. P.

Effect of blood lactate-guided conditioning of horses with exercises of differing durations and intensities on heart rate and biochemical blood variables¹

A. Lindner^*,2, H. Mosen^*, S. Kissenbeck^*, H. Fuhrmann and H. P. Sallmann

^* Arbeitsgruppe Pferd, Jülich, Germany 52428; and Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Leipzig, Germany 04159; and Institute of Physiological Chemistry, University of Veterinary Medicine, Hanover, Germany 30559

² Corresponding author: arnolindner{at}t-online.de

The velocity at which blood lactate concentration ([LA]) of 4 mmol/L is reached (v₄) is widely used to determine fitness, but there are few published data on using [LA] as a guide for the exercise speed for training in horses. In this study, the effect of 3 conditioning programs with [LA] guided exercise speeds on v₄, v₂₀₀ (speed at a heart rate of 200 beats/min), blood [LA], plasma FFA ([FFA]), and alanine concentrations ([alanine]), before and after exercise, as well as heart rate during exercise, of horses was examined. Six 2-yr-old Haflinger stallions underwent an initial treadmill-based standard exercise test (SET). A regression analysis [LA]-speed relationship was used to calculate v_1.5, v_2.5, and v₄. Horses were then randomly assigned to 1 of 3 conditioning programs according to a 3 x 6 Latin square design. During 6 wk, horses exercised on the treadmill every other day for 45 min at their calculated v_1.5 or v_2.5 or 25 min at their v₄. Each conditioning period (CDP) was followed by 5 wk without conditioning. At 2 and 9 d, and 5 wk, after the end of the CDP, the horses performed another SET to evaluate again the v₄ and v₂₀₀. Blood [LA], plasma [FFA], and [alanine] were measured before and after heart rate during exercise sessions 1, 11, and 21 in each CDP. None of the exercise programs had an effect on v₄ and v₂₀₀ (P > 0.05). The increase of the mean [LA] after exercise decreased during CDP (P < 0.05), and the increase of mean heart rate during exercise tended to decrease as well (P = 0.07). There was no difference among the conditioning programs. Plasma [FFA] before exercise was not influenced by the CDP (P > 0.05). The plasma [FFA] was always greater after exercise (P < 0.05), but there was no difference among conditioning programs. Overall, the increase was greatest after the 21st exercise session compared with the 1st and 11th exercise sessions (P < 0.05). The mean plasma [alanine] before exercise remained similar during all CDP (P > 0.05). Mean plasma [alanine] of the horses was increased after all exercise sessions measured (P < 0.05). There was no difference among conditioning programs (P > 0.05). It is concluded that conditioning with the exercise types used had small effects. This could have been because the exercise stress was too small, but also because the workload was not increased during the CDP.

Key Words: alanine • blood • conditioning • exercise • horse • lactate