Discussions on growing more durable equine athletes often revolve around developmental orthopaedic disease (DOD). What degree of DOD, if any, is acceptable or inconsequential to long-term athletic performance remains a question. Much effort has been directed toward diminishing or eliminating the incidence and severity of DOD, but with limited success. We must continue to define what degree the management decisions affect the horse during different stages of its growth. It would seem logical that the most profound influence would occur during the most rapid periods of growth. Therefore, concerns have been directed toward the last third of gestation and the possible indirect effect that broodmare management has on foetal development. The early postnatal period is another period of rapid growth; thus, the effect of broodmare management on lactation may affect the growth of the foal. Management will also have a direct effect on growth and development from weaning through to maturity. Recent research in other species as well as in horse suggests that genetic predisposition is the primary determinant of DOD. Non-nutritional management also may have significant effects on articular and skeletal health and athletic durability. Much effort has been directed toward nutrition and potential impact on DOD, but with limited success. Except for overt deficiencies, or perhaps excessive imbalances, nutrition does not appear to be a primary determinant of DOD, particularly of focal lesions associated with osteochondrosis. However, nutrition may serve a secondary role in diminishing the severity and incidence of DOD in horses genetically predisposed to such conditions. Producing horses that will have long-term and productive athletic careers requires sound management that starts at conception and continues throughout the life of the horse.

The purpose of the present study was to investigate the effect of the horse's laterality on the symmetry of rein tension in right-handed riders. Eleven right-handed riders rode both a right-lateralized (RL) and a left-lateralized (LL) horse. Rein tension was measured during three circles of walk, trot and canter and four walk–halt transitions in each direction. Tensions were recorded continuously using a rein tension meter. The LL horse was ridden with significantly stronger mean tension in the left rein than in the right rein (1.5 vs. 1.4 kg; P = 0.0352). Significantly more tension was applied to the outside rein in a clockwise (1.4 vs. 1.2 kg; P = 0.0202), but not in a counterclockwise, direction (1.3 vs. 1.2 kg; P = 0.49). Less minimum tension (0.06 vs. 0.29 kg) and greater maximum (6.4 vs. 3.9 kg) and range of tension (6.3 vs. 3.6 kg) occurred in the left rein of the RL horse (P < 0.0001) and the right rein of the LL horse (0.37 vs. 0.08 kg, 4.8 vs. 7.4 kg, 4.3 vs. 7.3 kg respectively; P < 0.0001). The results of the present study indicate that the different utilization of both reins is likely to be influenced by the laterality of both horse and rider. These findings may have important implications for equine training, since consistency of reinforcement is an important factor for equine learning success.

The assessment of the effect of race training on the locomotory apparatus can be confounded by tissue responses to the increasing training load, such as dorsal metacarpal disease. The aim of this paper was to examine the changes in gait during the early stage of race training in a cohort of 19.2-year-old Thoroughbreds, 11 of which had previously been exposed to spontaneous pasture exercise and also to preconditioning exercise from an early age (CONDEX), and the remainder had been exposed to only spontaneous pasture exercise (PASTEX). Data were collected 52, 60, 77, 109 and 176 days after the horses had entered the racing stable. At each examination, the horses were trotted in-hand on a hard asphalt surface, and kinematic data were collected. The horses trotted slowest on the first examination day, with a significantly longer and slower stride and associated percentage stance time. On day 77, the CONDEX horses trotted faster, had a longer stride length and achieved mid-stance earlier than the PASTEX horses. Across both groups, the introduction of galloping was associated with a significant reduction in stride duration (0.69 ± 0.01 vs. 0.66 ± 0.01 s, P = 0.001), stride length (2.49 ± 0.03 vs. 2.38 ± 0.02 m, P = 0.004) and stance duration (27.3 ± 1.0 vs. 32.0 ± 1.0%, P = 0.001). The changes in gait appeared to be associated with the introduction of galloping and the associated tolerance of the CONDEX group to the musculoskeletal loading.

Athletes of various sports are required to utilize mouthguards during practice and competitions for protection against orofacial and dental injuries, regardless of the effects on performance. Recent advances in neuromuscular dentistry have led to the development of a mouthguard touted also to enhance the performance through jaw realignment. The purpose of this study was to compare the effects of a neuromuscular dentistry-based mouthguard to a standard, custom-fitted mouthguard (CFM) on muscular endurance, anaerobic power and anaerobic capacity in competitive athletes. Professional and Division I college athletes (n = 22, Mweight = 86.2 ± 3.1 kg) participated in this double-blind, crossover study. Subjects were randomly assigned to order of use of either the experimental (Pure Power Mouthguard (PPM)) or the traditional CFM. Subjects completed two separate sessions in which they completed three performance tests, which included vertical jump (VJ), bench press (BP) and a 30 s Wingate anaerobic test (WAnT)+eight 10 s intervals, while wearing the assigned mouthguard. Significantly better performance was found for PPM compared with CFM for VJ (67.6+9.4 cm vs. 65.3+8.6 cm; P = 0.003), 30 s WAnT peak power (11.6 ± 1.7 W kg− 1vs. 11.1 ± 1.5 W kg− 1, P = 0.038), average peak power for WAnT+intervals (10.6 ± 1.4 W kg− 1vs. 10.1 ± 1.2 W kg− 1, P = 0.025) and average mean power for WAnT+intervals (9.0 ± 1.1 W kg− 1vs. 8.7 ± 1.0 W kg− 1, P = 0.034). There were no significant differences for either BP or 30 s WAnT mean power (P>0.48). Compared with a CFM, a neuromuscular dentistry-based mouthguard appears to enhance peak power output, performance and repeated maximal efforts. When required to wear a mouthguard, athletes may benefit from wearing a neuromuscular dentistry-designed mouthguard compared with a CFM.

The present study tested the hypothesis that lactate concentration ([La− ]) would differ between sample sites and between assay techniques that used different analytical substrates. Six clinically normal adult (two Thoroughbreds, three Standardbreds and one Quarter Horse) mares weighing between 435 and 560 kg were used in the study. Each mare performed an incremental exercise test (graded exercise test, GXT) where it ran on a treadmill at a fixed 6% grade. The GXT started at 3 m s− 1 for 1 min with increased in speed by 1 m s− 1 every 60 s until the horses completed the final 10 m s− 1 step. Jugular vein, pulmonary arterial and carotid arterial blood samples (14 ml) were collected before exercise and during the last 10 s of each step of the GXT. [La− ] was measured in whole blood (WB, no manipulations), total blood (TB, where the red blood cells were lysed) and plasma. Data were used to calculate the velocity to produce [La− ] of 4 mmol l− 1 (VLA4) and 10 mmol l− 1 (VLA10). Statistical analysis utilized a three-way ANOVA and, where appropriate, the Holm–Sidak or the Student Neuman–Keuls method for post hoc comparisons. The null hypothesis was rejected when P < 0.05. There was an effect of exercise intensity on [La− ] for all three methods (P < 0.001) with all means during exercise significantly greater than the resting mean, and there were differences due to method (i.e. analytical substrate) (P < 0.001) and sample site (P = 0.043). Comparisons of least-squared means (LSM ± SE) within site revealed that there was a difference (P < 0.05) between jugular vein (5.41 ± 0.24) and carotid artery (6.24 ± 0.24) and between carotid and pulmonary artery (5.98 ± 0.24). There was no difference (P>0.05) between jugular vein and pulmonary artery. Within method, there was a difference (P < 0.05) between WB (6.54 ± 0.36) and TB (5.06 ± 0.36) and between TB and plasma (6.04 ± 0.64), but there was no difference (P>0.05) between WB (6.54 ± 0.36) and plasma (6.04 ± 0.64). Further analysis of the data demonstrated that the method and sample site influenced (P < 0.05) VLA4 and VLA10.

To determine the incidence of abnormal or delayed systolic blood pressure recovery (SBPR) in relation to the level of adiposity in the adult population; the risk of delayed SBPR in overweight/obese adults relative to their non-overweight/obese controls; and the best predictor of third-minute systolic blood pressure (SBP) ratio and delayed SBPR among four obesity indices – body mass index (BMI), waist circumference, waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR). Two hundred and ninety-six apparently healthy adults aged 18–48 years participated in the study. Anthropometric variables were measured, and subjects performed cycle ergometer exercise at 80% age-predicted maximum heart rate. Blood pressure (BP) and heart rate were measured before and during exercise. BP was further measured immediately after exercise and subsequently at 2 min intervals until recovery to resting position. The incidence and risk of delayed SBPR were higher in the overweight/obese individuals than those in the non-overweight/obese controls. Multivariable regression analyses revealed that BMI in males and WHtR and WHR in females had the strongest relationships (P < 0.05) with post-exercise SBPR. WHtR and BMI had the strongest associations with increased risk of delayed SBPR in the non-overweight/obese and the overweight/obese individuals, respectively. The present findings suggest that WHtR in the non-obese individuals and BMI in the overweight/obese individuals may be the best obesity variables for the prediction of abnormal post-exercise SBP response. Our findings further suggest that a reduction in body weight through healthy activities such as exercise may reduce the incidence and increased risk of delayed SBPR and its associated cardiovascular risks.

In a previous study of young Norwegian–Swedish coldblooded trotters (NSCT), aged 17–24 months, a high proportion (>30%) of type I fibres in the gluteus medius was found in 33 of 141 horses. These findings were surprising and the purpose of the present study was to find an explanation for the high type I fibre proportion in these horses. Possible explanations might be an inaccuracy in the procedure of analysing the biopsy sample, inaccuracy in the method of sampling or a muscular disorder in these individuals. Further, the high type I fibre proportion might be age related. The accuracy of the procedure for determination of the fibre composition from a biopsy sample was tested by analysing the same biopsy sample at two different occasions in nine horses. Four of the nine horses had high type I fibre proportions on both occasions and the five others had proportions within the expected range on both occasions. The repeatability of the procedure was tested by an agreement analysis, where the agreement index (AI) is calculated. This analysis revealed an AI of 0.70, where an AI >0.5 shows a good repeatability. Eight of the nine horses were re-sampled at the age of 3 years. At this age, all horses had type I fibre proportions < 30%. The biopsy technique with an absolute depth of 4 cm might give a relatively more superficial sample of the muscle in larger horses, which may explain the age-related differences. However, in young horses, high proportions of type I fibre seemed to be found in the larger individuals. The light sedation given to the horses before sampling may also have influenced the relative sampling depth. Muscular disorders were ruled out as performances in the 3-year season did not differ between 33 horses with high type I fibre percentage and 106 horses with normal type I fibre percentage. In conclusion, the high proportion of type I fibres in some young NSCT was not caused by the analysing procedure or by muscular disorders, but is probably related to the sampling point within the muscle.