Human heart rate monitors (HRMs) are frequently used in equine studies to measure heart rate (HR) and interbeat intervals (IBIs). However, to date, the most commonly used HRM (the Polar® system) in horses has not been validated against simultaneously recorded electrocardiogram (ECG) signals during a range of ambulatory conditions. Polar® S810i and ECG IBIs were simultaneously recorded from six horses under three conditions commonly included in behavioural observation: standing at rest, loose in the stable and at liberty in a field. Following recording, Polar® IBI data were corrected for error processing in cardiac data. Corrected and uncorrected Polar® data were then compared with simultaneously recorded ECG data using a variety of commonly measured time and frequency domain parameters (e.g. HR variability (HRV)). Polar® data collected while horses were stabled or in the field were significantly different from ECG data, even following correction of the data, and therefore, it may not be possible for the two systems to be used interchangeably. This study indicates the need for caution while using Polar® S810i for collecting HRV data, unless horses are stationary, and even when the IBI data are corrected for measurement error.

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.

This study investigated intra-oral behaviours in horses wearing different bits with and without rein tension. Six riding horses wore a bridle and three bits: jointed snaffle, KK Ultra and Myler comfort snaffle. Lateral fluoroscopic images (30 Hz) were recorded for 20 s for each bit with loose reins and with 25 ± 5 N bilateral rein tension. The videos were analysed to determine time spent in the following behaviours: mouth quiet, gently mouthing the bit, retracting the tongue, bulging the dorsum of the tongue over the bit, lifting the bit and other behaviours that were performed infrequently. Repeated-measures ANOVA indicated that behaviours did not differ between bits, so bit type was not predictive of behaviour, but there were significant effects of horse and rein tension. Horses spent less time quiet and more time mouthing the bit, retracting the tongue and bulging the tongue over the bit when tension was applied.

The objective of this study was to characterize the nutrition and feeding management practices, including concentrate and supplement use, of three-day event horses prior to and during high-level competition. Subjects were horses competing in one of two divisions at the Jersey Fresh Three-day Event in Allentown, NJ, in 2006 and/or 2007. Body weight and condition score of horses, and feeding management surveys, were completed prior to the start of competition with weight of hay and concentrate taken in 2007. Two sample t-tests were used to compare the data between divisions within each year of the study. For both years, the majority of horses were of the male gender and Thoroughbred breed, aged 11.1 ± 0.3 years. There were no differences between divisions within the year for any of the variables measured. The average numbers of supplements fed on a regular basis to horses competing in the 2006 Concours Complet d'Equitation International (CCI**), 2006 CCI***, 2007 CCI** and 2007 CCI*** events were 4.2 ± 0.4, 4.2 ± 0.3, 4.2 ± 0.5 and 4.3 ± 0.7, respectively. In both years, the most administered type of oral supplement was electrolytes, followed by plain salt and oral joint compounds. The majority of horses in both years did not have any change in their forage and concentrate feeding prior to being transported to the show facility. Feeding practices before and after cross-country varied between years and divisions, but most horses had feed withheld for about 2–4 h prior to the event. The majority of feeding management practices followed research-driven recommendations. However, the relatively high average supplement use per horse raises questions about over-supplementation and/or nutrient interactions in these horses.

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.

To examine the management and training practices of 2-year-old racehorses, cross-sectional survey data were collected from 55 racehorse trainers in the Central Districts (n = 15) and the Northern Districts (n = 40) of New Zealand during summer 2007–08. Trainers in the Northern Districts had a higher proportion of 2-year-olds in work at one time (0.31 vs. 0.22, P = 0.001) than trainers in the Central Districts. Group S (trainers with 10–19 horses in work) had a higher proportion of 2-year-olds in work than both groups M (20–30 horses in work) and L ( ≥ 40 horses in work) (0.38 vs. 0.24 vs. 0.29, respectively, P = 0.001). Most horses were broken prior to the start of the official 2-year-old racing year. Most trainers had a standard pattern of training, and they cited early education as the primary reason for training 2-year-olds; the primary training milestones used to evaluate the horses' training were the first training gallop and the entry in a race trial. Training programmes were geared towards 2-year-olds being ready for trialling and racing earlier in the Northern Districts than in the Central Districts. Training practices were affected more by the trainer's location than by the number of horses trained.

This study aimed to determine whether training aids (side reins and a Pessoa) increased the use of the longissimus dorsi when horses are being lunged. Horses were lunged on a circle under four different conditions on the left and right reins in walk and trot, and electromyographic (EMG) and speed measurements were taken using surface EMG at T16 and GPS, respectively. The EMG intensity was substantially greater for the longissimus dorsi on the inside of the circle. Differences occurred in both the timing and the intensity of the EMG between the conditions. At walk, the EMG intensity was the greatest for the control condition and at trot the EMG intensity was the greatest for the control and Pessoa control conditions. It is concluded that the training aids of side reins and a Pessoa do not increase the use of the longissimus dorsi to stabilise the back.

Few studies exist regarding the physiological responses of equestrian riders during actual or simulated competition. Interest has proliferated in recent years on the responses of riders, which is mainly due to the fatal tragedies that occurred in eventing in the late 1990s. More emphasis is also being placed on the importance of riders, fitness in order to improve athletic performance at the international level. The aim of the present study was to investigate the fitness and exercise capacity of female equestrian athletes, and to relate this to the metabolic requirements of dressage (DR), showjumping (SJ) and cross-country (XC) phases of the one-day event. Sixteen female collegiate riders (age = 24.5 ± 7.7 years; height = 166.6 ± 3.8 cm; weight = 60.4 ± 6.0 kg) competed in a simulated Horse Trials Pre-Novice competition riding either their own horse or one familiar to them. Anthropometric data were obtained for each rider (body mass index (BMI) = 21.7 ± 1.9; % body fat (BF) = 23.4 ± 5.3; lean body mass (LBM) = 48.5 ± 3.6). Each subject successfully completed all three phases of the event. There was a progressive increase in oxygen consumption (VO2) during the three phases (DR, SJ and XC) from a mean value of 20.4 ± 4.0 ml kg− 1 min− 1 (DR), 28.1 ± 4.2 ml kg− 1 min− 1 (SJ) to 31.2 ± 6.6 ml kg− 1 min− 1 (XC) (P < 0.001). Heart rate data showed a similar trend from a mean value of 157 ± 15 beats min− 1 (DR), 180 ± 11 beats min− 1 (SJ) to 184 ± 11 beats min− 1 (XC) (P < 0.001). Mean lactate concentration increased progressively from resting values: rest 2.5 ± 1.3 mmol, DR 4.8 ± 1.8 mmol, SJ 7.8 ± 2.4 mmol and XC 9.5 ± 2.7 mmol (P < 0.001). Urine osmolality was significantly (P < 0.001) increased from a pre-competition mean of 0.488 ± 0.270 mOsmol l− 1 to a post-competition mean of 0.684 ± 0.230 mOsmol l− 1. Mean hand grip strength was observed to decrease significantly (P < 0.01) from a pre-value of 32.3 ± 6.3 kg to a post-value of 29.8 ± 5.5 kg. Mean weight loss pre- to post-competition was 1.6 ± 1.1% body weight (P < 0.01). In conclusion, the study emphasises the variability in metabolic cost between riders performing in the same simulated competition but riding different horses, and highlights the difference in metabolic demand between the different phases.

Overtraining is a significant cause of poor athletic performance in both human and equine athletes. In humans, overtraining syndrome has been defined as an imbalance between training and recovery manifesting as a syndrome of chronic fatigue and poor performance that may be accompanied by physiological and psychological changes. A similar syndrome has been described in horses using both cross-sectional observations and longitudinal studies with progressively increasing training loads until signs of overtraining were observed. The original cross-sectional studies of overtraining in horses linked the syndrome to increased red cell volume. However, more recent longitudinal studies revealed that overtraining is not always associated with increased red cell volume. Once other causes of poor performance have been ruled out, overtraining syndrome should be suspected in horses with evidence of sustained decreased performance in association with one or more physiological or psychological (behavioural) signs. While no single physiological marker is able to identify the syndrome, accompanying physiological signs in horses may include a decrease in body weight, elevated heart rates during exercise, lower plasma cortisol response to exercise, or elevated muscle enzymes or gamma glutamyl transferase concentrations. Behavioural signs were consistent and an early marker of overtraining syndrome in longitudinal studies in horses, and more research on developing behavioural scores to assist in early detection of overtraining syndrome in horses -as has been achieved for humans- is warranted. Two successful models of overtraining syndrome in horses have been developed, both of which appear to meet the criteria of overtraining syndrome rather than overreaching. Overtraining syndrome in horses is real, reproducible and future research should ensure the criteria for diagnosis of overtraining syndrome are met.

The objective of this study was to compare exercise-induced inflammatory responses in horses undergoing three different treadmill exercise tests. Mares completed a graded exercise test (GXT), an interval exercise test (IET) and a repeated sprint exercise test (RSET). Blood and synovial fluid samples were taken 24 h before (PRE) exercise, 20–30 min, 2 and 24 h following exercise (REC). Blood was analysed for total protein, haematocrit and total nitrite concentration. Pro-inflammatory and anti-inflammatory cytokine transcripts were measured in whole blood using quantitative real-time polymerase chain reaction. Synovial fluid was analysed for total nitrite. Mares spent more time at greater than 90% of their maximum heart rate during the RSET than they did for either the GXT or IET. There was an effect of exercise test (P < 0.0001) and exercise test by sample interaction (P = 0.010) for plasma total nitrite. Pro-inflammatory cytokine transcripts and plasma total protein were elevated (P < 0.05) after exercise and there was a higher (P < 0.0001) nitrite concentration in tibiotarsal joints compared with radiocarpal joints. As hypothesised, the higher-intensity exercise test (RSET) resulted in greater nitric oxide responses as well as markers of exercise intensity compared with less intense exercise tests (IET, GXT).

The study was designed in order to gain a better understanding of whether the lack of competition stress and/or sampling time had an influence on circulating β-endorphin, adrenocorticotrophin (ACTH) and cortisol modifications after experimental showjumping sessions and to study the effects of fence height on hormone changes. Hormone levels were recorded before exercise in basal conditions and after warm-up, then 5 and 30 min post-exercise. Using a randomized crossover study design, six horses were studied during three experimental showjumping sessions over fences of different heights: 1.00 m (session 1), 1.10 m (session 2) and 1.20 m (session 3). The showjumping exercise did not modify plasma β-endorphin and serum ACTH concentrations after session 1, and tended only to maintain higher values than basal after both session 2 and session 3. The interaction fence height/time was not statistically significant for either β-endorphin or ACTH changes. Sampling time significantly affected both β-endorphin (F = 2.88; P < 0.04) and ACTH (F = 3.84; P < 0.01) changes. Serum cortisol levels were always higher than basal 5 min post-exercise, with levels falling at 30 min. The interaction fence height/time was not statistically significant, while sampling time significantly affected the results (F = 7.96; P < 0.0002). This study demonstrated no significant effects of fence height on β-endorphin, ACTH and cortisol changes. The sampling times adopted affected post-exercise changes in plasma β-endorphin, ACTH and cortisol and could have masked the effects of fence height on hormone modifications.

There are many instructional texts for dressage management and training, but little scientific knowledge of these practices. It was hypothesized that there would be an effect of horse competition level on management and training. The objectives were to record rider, horse, management and training information from UK dressage horses and to investigate relationships between the variables. A questionnaire-based study was undertaken in all the UK-registered dressage horses. Data from 2554 respondents showed most riders in groups 7/6 with horses competed at novice medium and trained one level higher. Horses were 164–171 cm and warmbloods were the predominant breed. Age and time in competition increased in training and competing from Preliminary to Prix St George. Horses competed twice per month except at Grand Prix (once per month). Most horses had 15–30 h turnout per week. Ninety-five per cent of horses received non-dressage exercise; hacking was the most common, then lunging and jumping. Non-elite horses were significantly more likely to be hacked/jumped than elite. Horses received dressage training three to four times a week, mean warm-up of 16 min and cool-down 11 min at all levels. Mean training duration was 36 min: 21% walk, 45% trot and 32% canter. Preliminary, Novice, Intermediare I and Grand Prix horses trotted most and cantered least in training. Overall, time spent in transitions (30–39%), specific movements (30–39%), working paces (40–49%), collected (10–19%) and extended (0–9%) varied between levels; elite horses spent more time in collected and less time in working than non-elite. Overall, there were differences in training and management practices between competition levels. This information provides baseline data on which to provide future advice.

Numerous studies have described the cardiorespiratory and kinematic responses of horses running on level and positive gradients, but little attention has been given to exercise on negative gradients, despite the fact that many horses compete over variable terrain. The purpose of this study was to describe the heart rate (HR), estimated net transport cost (COT) and stride characteristics of horses exercising at walk and trot on positive and negative gradients. Five horses (mean ± SD, 517 ± 42 kg) were acclimated in walk and trot on positive and negative gradients prior to data collection. HR and stride characteristics were measured over the last minute during walk (1.9 m s− 1) and trot (3.5 m s− 1) on a treadmill set at − 6, − 3, 0, 3 and 6%. Compared with level exercise, HR was higher at both 3 and 6%, and lower at − 3 and − 6% in walk and trot (P < 0.001). The estimated COT (beats kg− 1 m− 1 × 103) increased by an average of 30 and 48% at 3 and 6% gradient in walk, and by an average of 29 and 46% at trot compared with level exercise (P < 0.001), respectively. At negative gradients, COT decreased by 20 and 33% at walk, and by 17 and 24% at trot for − 3 and − 6% gradients (P < 0.001), respectively. Stride duration and stride length were longer, and stride frequency was lower at negative gradients compared with positive gradients (P < 0.001). In trot, the duty factor was increased in the forelimb and decreased in the hindlimb on negative compared with positive gradients (P < 0.001). Physiological workload in horses reduces from positive to negative gradients in walk and trot; however, the metabolic advantage of faster gaits, estimated by COT, diminishes as the gradient becomes more negative. This may reflect increased energy demands associated with maintaining balance and braking on negative slopes, and the locomotion strategy adopted.

This study hypothesized that ginger (Zingiber officinale) and cranberry (Vaccinium macrocarpon) extracts would alter the physiological response to exercise as well as markers of muscle damage, and mRNA expression for the inflammatory cytokines tumour necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and interleukin-6 (IL-6) after an exhaustive bout of exercise in horses. Nine unfit Standardbred mares (age 10 ± 4 years, ~450 kg) completed three graded exercise tests (GXTs) in a crossover design, where they were assigned to the initial order of treatment in a randomized fashion. The GXTs were conducted between 07.00 and 12.00 hours, 7 days apart. Mares received either water (2 l), cranberry (~30 g in 2 l of water) or ginger (~30 g in 2 l of water) extract 1 h prior to testing. Blood samples were taken prior to dosing (pre-exercise), at the end of each step of the GXT, at the end of the exercise and at 2, 5 and 30 min, 1, 2, 4 and 24 h post-GXT. Plasma total protein (TP) concentration and haematocrit (HCT) were analysed immediately following the tests. Analysis of creatine kinase (CK) and aspartate aminotransferase (AST) was done commercially. There was no effect of treatment (P>0.05) on VO2max, run-time to fatigue, core temperature, TP or HCT. CK was substantially elevated (P < 0.05) in the ginger group at 4 h post-GXT. All CK levels returned to baseline 24 h post-GXT. No change (P>0.05) was noted in AST. A slight increase (P < 0.05) in CK was seen in all groups at 2 h post-GXT. The cranberry group had significantly lower TNF-α mRNA expression than the control and ginger groups. Ginger appeared to influence (P < 0.05) the upregulation and expression of IFN-γ mRNA at 30 min post-GXT, but, more strikingly, significantly decreased recovery time defined as the time for VO2 to recover from the peak observed at fatigue to a post-exercise plateau (ginger = 101 ± 3 s, water = 130 ± 14 s, cranberry = 131 ± 16 s). No effect of treatment or exercise (P>0.05) was seen on IL-6 mRNA expression. Results suggest that cranberry extract blunts the upregulation and expression of TNF-α mRNA, while ginger extract reduces cardiovascular recovery time in horses completing a short, exhaustive bout of exercise.

An understanding of the physiological and metabolic demands of competition is essential for the development of training regimens that elicit adaptations appropriate for the sport being participated in. Despite the fact that dressage is a major sport and one of only three equestrian Olympic disciplines, to date there appear to be no studies that have described the heart rate of horses performing competitive dressage in any detail. The present study was therefore undertaken to describe the physiological demands of dressage competition. Thirty-five horses competing in a total of 50 dressage tests, 36 of which were at British dressage (BD) elementary level and 14 at BD medium level, were studied. The horses studied were predominantly Warmblood or Thoroughbred cross geldings with an age range from 6 to 17 (mean ± SD age of 10.0 ± 2.5 years). The average durations of warm-up for all horses competing were 31.3 ± 15.4 min at elementary level (n = 36) and 31.4 ± 10.0 min at medium level (n = 14; P>0.05). The mean and mean peak heart rates for horses warming up for elementary level were 91 ± 13 and 146 ± 35 bpm (beats min− 1), respectively, and were not different to that for horses warming up for medium level (mean 91 ± 10 bpm; peak: 144 ± 32 bpm; P>0.05). The mean and mean peak heart rates for all horses while competing at elementary level (n = 36) were 102 ± 13 and 132 ± 20 bpm, respectively, and 107 ± 8 and 132 ± 10 bpm, respectively, for medium level (n = 14), and were not significantly different (P>0.05). Mean heart rates during competition were significantly higher compared with that during warm-up for both elementary and medium levels (P < 0.001). Mean heart rate during competition (elementary and medium data combined) was significantly correlated with mean heart rate during warm-up (r2 = 0.503; n = 50; P < 0.001). There was no association between heart rate, warm-up duration and score or placing. These observations suggest that competitive dressage at BD elementary and medium levels is only moderately aerobically demanding.

There is a known relationship between the way athletes interpret the feelings of pre-competitive arousal and their subsequent performance. In equestrian sports, riders' interpretation of their horses' temperament may be an additional unique factor that influences the levels of riders' arousal and performance. The aims of this study were to investigate the effect of intensity and direction of arousal and self-confidence on dressage and showjumping performance, and to investigate how perception of equine temperament traits affects arousal and performance components. Twenty-two student riders (6 males and 16 females) competing on unfamiliar horses were asked to participate in the study. Prior to the competition, riders completed the Revised Competitive Sport Anxiety Inventory-2 with direction scales, and rated their horses' temperament traits using an adapted Five Factor Personality Questionnaire. Dressage performance scores were found to be positively correlated with cognitive arousal intensity (r = − 0.5, P < 0.05) and self-confidence intensity (r = 0.59, P < 0.05). Showjumping faults were negatively correlated with somatic arousal direction scores (r = − 0.5, P < 0.05). The ‘active’ equine temperament was positively correlated with somatic arousal intensity in showjumping (r = 0.5, P < 0.05) and negatively correlated with cognitive arousal direction in dressage (r = − 0.71, P < 0.005). These findings suggest that riders' self-confidence and perception of their horses' temperament are important factors in the relationship between arousal and performance.

Obesity is considered a risk factor for laminitis, insulin resistance and other medical problems in horses. The objective of this study was to test the hypothesis that a feeding and exercise programme would induce weight loss and affect indices of health in overweight horses. Twenty-three overweight (BCS 6.5–9.0) QH and TB horses were assigned to three groups: calorie restriction (DIET), calorie restriction plus exercise (DIETX) and a control group at weight maintenance (CON). Measurements included body weight, body condition score, rump fat thickness, glucose, insulin, leptin, non-esterified fatty acids (NEFA) and triglycerides. Frequently sampled intravenous glucose tolerance tests measured insulin sensitivity (SI), glucose effectiveness and acute insulin response to glucose (AIRg). Disposition index (DI) was calculated. DIETX underwent a fitness test (graded exercise test) on a treadmill before and after the experimental period, and performed a standardized submaximal exercise regimen in an Equi-ciser™. Horses in the DIETX group lost more weight (P < 0.01) than DIET or CON. DIET also lost more weight versus CON (P < 0.05). All groups had decreases (P < 0.05) in BCS, with DIETX and DIET exhibiting the largest decreases. DIET and DIETX decreased (P < 0.05) in rump fat thickness. Cortisol decreased (P < 0.05) in DIET, and NEFA decreased in DIETX pre- versus post-weight loss. There were decreases (P < 0.05) in leptin and AIRg in DIET and DIETX pre- versus post-weight loss. DI was decreased (P < 0.05) in DIET and CON. SI was decreased (P < 0.05) only in CON. Calorie restriction and calorie restriction plus exercise programmes were successful in achieving weight loss in overweight horses. Indices of obesity, physiological stress and fat metabolism can be significantly altered with calorie control and exercise.

The objectives were to investigate the effects on fluid balance, digestion and exercise response in Standardbred horses in race training when feeding silage, haylage or hay-only diets. In experiment (exp) 1, five Standardbred geldings were fed forage-only diets: hay (82% dry matter, DM) and silage (45% DM) for 23 days in a crossover design. Total collection of faeces and urine was performed. In exp 2, six Standardbred geldings were fed forage-based diets: haylage (68% DM) and silage (41% DM) for 17 days in a crossover design. On day 17, an incremental interval exercise test was performed on an oval racetrack. In exp 1, horses drank more on the hay than on the silage diet, but total water intake (drinking+water in feed) was higher and resting values of total plasma protein (TPP) was lower on the silage diet. Total water output per day did not differ and therefore the estimated evaporation was larger on the silage than the hay diet. The apparent digestibility was higher on the silage than the hay diet. In exp 2, heart and respiratory rate, TPP and lactate and blood pH did not differ between the haylage and silage diets during and after the exercise test. In conclusion, feeding silage did not affect faecal water content, but apparent digestibility and estimated evaporative fluid loss were higher on the silage diet compared with the hay diet. The silage did not adversely affect the response to intensive exercise compared with haylage. However, the estimated higher evaporative fluid loss on the silage diet compared with the hay diet might cause an unnecessary challenge during more prolonged exercise.

Warm-up prior to equestrian competition is considered an essential element of preparation. Little work has been previously published regarding warm-up practices within equine competition in relation to either reducing risk of injury and/or improved performance. This pilot study undertook a comparative investigation into the differences in warm-up practices at two distinctly different levels of show jumping competition. The study indicates that significant differences (P < 0.001) are apparent between the total time spent warming up between the levels of competition. Additionally, differences between various specific elements of warm-up were observed between the two levels.

The aim of this study was to investigate the effect of high-intensity training on lactate transporters (monocarboxylate transporters (MCTs)) in Thoroughbred horses. Five Thoroughbreds (three males and two geldings; 3–10 years old; 478 ± 13 kg) ran at 100% maximal oxygen uptake (VO2max) for 1 min (3 days per week, 3 weeks) or 2 min (2 days per week, 4 weeks) on a treadmill for 7 weeks. VO2max and ability to sustain an incremental all-out test of maximal running were measured, and muscle samples were obtained from the gluteus medius muscle at rest before and after the training. The performance in the all-out test and VO2max were increased after the training. The protein content of MCT1 and MCT4 in the gluteus medius muscles was not significantly altered. However, MCT1 showed a relationship with the duration of maximal exercise after the training. The changes in MCT4 showed a relationship with the increase in exercise duration by the training. These results suggest that in Thoroughbreds, although the overall changes in MCT protein after endurance training are small, MCT1 and MCT4 can play important roles in the capacity to sustain maximal exercise.