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Effect of different blood‐guided conditioning programmes on skeletal muscle ultrastructure and histochemistry of sport horses
Author(s) -
Lindner A.,
Dag Erginsoy S.,
Kissenbeck S.,
Mosen H.,
Hetzel U.,
Drommer W.,
Chamizo V. E.,
Rivero J. L. L.
Publication year - 2013
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/j.1439-0396.2012.01283.x
Subject(s) - myofibril , conditioning , medius , skeletal muscle , medicine , muscle hypertrophy , endocrinology , anatomy , chemistry , statistics , mathematics
Summary The effects of three different blood‐guided conditioning programmes on ultrastructural and histochemical features of the gluteus medius muscle of 2‐year‐old sport horses were examined. Six non‐trained Haflinger horses performed three consecutive conditioning programmes of varying lactate‐guided intensities [velocities eliciting blood lactate concentrations of 1.5 (v 1.5 ), 2.5 (v 2.5 ) and 4 (v 4 ) m m respectively] and durations (25 and 45 min). Each conditioning programme lasted 6 weeks and was followed by a 5‐week resting period. Pre‐, post‐ and deconditioning muscle biopsies were analysed. Although training and detraining adaptations were similar in nature, they varied significantly in magnitude among the three different conditioning programmes. Overall, the adaptations consisted in significant increases in size of mitochondria and myofibrils, as well as a hypertrophy of myofibrillar ATPase type IIA muscle fibres and a reduction in number of type IIx low‐oxidative fibres. Together, these changes are compatible with a significant improvement in both muscle aerobic capacity and muscle strength. The use of v 1.5 and v 2.5 as the exercise intensities for 45 min elicited more significant adaptations in muscle, whereas conditioning horses at v 4 for 25 min evoked minimal changes. Most of these muscular adaptations returned towards the pre‐conditioning status after 5 weeks of inactivity. It is concluded that exercises of low or moderate intensities (in the range between v 1.5 and v 2.5 ) and long duration (45 min) are more effective for improving muscle features associated with stamina and power in sport horses than exercises of higher intensity (equivalent to v 4 ) and shorter duration (25 min).