Welcome to the first topic for 624EHS - Contemporary Issues in Equine Science.
This topic is all about rider weight. You are required to contribute to this blog as a mock in preparation for CW3 for this module. You have from now until 11:59 pm on Monday 18th of October 2021 to contribute to this blog, to debate the issues surrounding rider weight. Ensure you can also evidence your opinions and remember that you are also required to submit a reference list (word document emailed to module leader) by 11:59 pm on Monday 18th of October. You will be graded on the quality and quantity of both your blog contributions and your reference list. Remember, the point of this is to debate the issues, so you should be replying to other posts as well at creating new discussion points. I will be keeping an eye on the blog and will add appropriate comments to help you debate this topic, but if you have any issues, you should email me. Please note that this topic 1, will serve as a mock and will not count towards your final coursework 3 mark, however you will receive feedback on this topic on the 1st of November 2021, to ensure that you are on the right track for future topics. Please remember to register your name with your comments so that I have a record of your contributions.Rosa
Rider weight is a highly debated and controversial topic, which should be handled delicately and with care. It is recommended that horses should not carry above 15 to 20% of the horses Body weight, for example: 20% of a 500kg horse means that the maximum weight a rider can be is 50kg (8 stone). Furthermore, the federation Equestre suggests that endurance riders should weight a minimum of 75kg (Draper, 2017). (comment from a previous student)
ReplyDeleteThe influence of rider weight on horse welfare, health and performance is still debated and remains a controversial and highly sensitive topic, but current recommendations of riders remaining within 15-20% of the horse’s BW have been challenged in recent studies such as Christensen et al 2020 where findings concluded that increasing the weight of the horse’s regular rider by 15% and 25% did not result in any significant changes to the horses behaviour, gait symmetry or physiological responses during low-intensity exercise. Cortisol levels increased in response to exercise, but did not increase when the rider became heavier.
ReplyDeleteAlthough Christensen et al 2020 study cannot be directly contrasted to the current recommendations as it only looked at increasing the horses regular riders weight, not necessarily to 15-20% of the horses BW; meaning that the riders could still potentially be within 20% of the horses BW if they were especially light (EG if the rider was very light and rode a heavier draft type breed). Similarly, Christensen et al 2017 could perhaps be used to argue Drapers 2017 75kg ruling on endurance riders, but the argument would be more poignant if Christensen et al had included a higher-intensity round as-well as a standard dressage test.
DeleteIrregardless, other aspects such as saddle fit, rider ability and balance must be accounted for when assessing the effect of weight on horse, as weight distribution is potentially as important if not more so than the weight bared.
Christensen et al. (2020) found rider weight between 15 and 20% did not induce any short term alterations in cortisol levels, heart rate, behaviour and gait symmetry during low level exercise.
DeleteStefánsdóttir et al. (2017) increased the body weight of riders up to 35%, which is common for the Icelandic horse used. Increasing the body weight above 20% did induce a physiological response from the horses. Heart rate, lactic acid, rectal temperature and breathing frequency increased.
Both research studies used the same rider and added weight, therefore not taking into account riders experience, balance and how the rider fits the tack.
Both studies also recommend more research into the area to consider the other variables. (comment from a previous student)
Other rider-related factors both studies did not take into account are items such as crookedness, inability to ride in rhythm with the horse, inability to work the horse in a correct frame to improve core strength and muscular support of the thoracolumbar spine of the horse. Additionally, if the riders own alignment is wrong, they may be putting pressures on areas of the horse which may lead to compensation in other parts of the body, for both rider and horse. According to Greve and Dyson (2013), if these factors are not corrected they may all contribute to poor performance and health implications to varying degrees.
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ReplyDeleteIcelandic horses are often spoken of when investigating the effect of rider weight as they are often ridden by riders that far outweigh the recommended 20% rule. However, a study by Jensen et al. (2016) found that 24.0 % of mature Icelandic horses in Denmark are overweight or obese which is interesting because Stefánsdóttir et al. (2017) noted that the horses used in the study mainly worked aerobically until BWR reached 22.7%, but considerable individual differences (17.0% to 27.5%) existed, differences which were linked to BCS. If the horses Stefánsdóttir et al. (2017) used were indeed obese themselves, it would effect HR, lactic acid and breathing frequency following light exercise, with or without a rider and may explain the considerable individual differences seen between the participating horses.
This is supported by Garlinghouse and Burrill's (1999) study of 360 endurance race horses, primarily of Arabian decent. It was concluded that BCS is a more important factor than the weight of the rider, or the rider weight in relation to the weight of the mount.
Stefánsdóttir et al., (2017) found that horses tended to work more aerobically until the body weight of the rider reached 22.7%, however, researchers deemed this to be due to the horses back confirmation rather than weight. Furthermore, Gunnarsson et al., (2017) also found that Body weight of the rider had no effect on beat, symmetry and height of the front leg lifting within tolt (Icelandic horses).
DeleteContradictory, to these papers, increased rider weights negatively influenced thoracolumbar width changes with exercise, increasing the tension and pain the horse endures when ridden (Test, 2018). According to Christensen et al., (2020) when ridden increased salivary levels were due to exercise rather than weight. However, Roberts et al., (2018) found that salivary cortisol levels were greater in riders of heavier body weights which contradicts other research (comment from a past student)
Ill-fitting saddles and their negative effects may be accentuated by excessive rider weight. TEST, P.A.S.E. (2018) conducted a study looking into The influence of rider weight on exercise induced changes, six horses in regular work were ridden by four riders of equal ability, but differing rider: horse bodyweight ratios and it was found that the mean change in thoracolumbar width after exercise was significantly different between the light rider (>10 ≤ 12%) and the Heavy rider (>15<18%). There was no significant increase in the tension or pain scores for the light rider although tension scores increased significantly for the Moderate (>12 ≤ 15%) and Heavy riders. The saddles were too small for the heavy rider, but all saddles were ill fitted, this is in line with riding schools as they all get varying weights and some saddles may be ill fitted to the horses. This study also lines with the comments made by Leanne and supports the theory that saddle fit is an important factor to consider when looking at rider weight. (comment from past student)
ReplyDeleteQuiney and Dyson (2018) also investigated the effect of rider:horse bodyweight ratio on thoracolumbar dimensions and epaxial muscle tension and pain. Results showed thoracolumbar width increased with light and moderate riders (3.9% and 1.9% respectively) but decreased with heavy and very heavy riders (3.4% and 2.8% respectively). No significant increases in tension or pain scores were noted for light riders but did significantly increase with moderate and heavy riders. Additionally there was a trend of increased pain scores for very heavy riders (P = 0.08).
DeleteSimilarly, saddle-fit was an issue in this study: saddles were well fitted to light and moderate riders but too small for the heavy and very heavy riders, making it difficult to separate the effects of saddle fit and rider size. Thus, the trends found cannot be concluded as rider size causality. However, the authors did conjecture that high rider:horse BW ratios negatively influenced thoracolumbar width changes whilst positively influencing tension and pain, and that excessive rider weight may accentuate the negative effects of an ill-fitting saddle.
Irregardless of the studies limitations, Quiney and Dyson (2018) drew comparisons from ‘real life’ scenarios, such as riding schools where often horse, rider and saddle are not well suited to each other.
a study by Benton (2006), examined how rider weight can have an effect on the horses stride of motion. They used 3 middle aged quarter horse geldings in normal conditions where they measured the duration of the swing phase, phase suspension, stride and stance phase. She measured this with a rider and then added weights of 20lbs and 40lbs during working trot (total weight of 170.7lbs +- 6lbs).
ReplyDeleteResults shows that all horses had changes with the extra 20lbs weight, causing their stance phase to lengthen and suspension phase at trot to shorten. At 40lbs 2 horses had the same changes as the 20lbs weight.
This shows that a riders weight will have an effect on the horses gaits during motion with extra added weight of the rider. (comment from past student)
Bentons (2006) may have found that two of the horses carrying an extra 40lbs of weight caused the stance phase to lengthen and suspension phase at trot to shorten. However, the third horse's results in the 40Ibs group were closer to that of the control group, unlike the other two. These results do show that the horse's gait responds to rider weight, but that further study is needed to determine the exact effect on the horse's back and speculate the long term implications from those changes in gait. Perhaps this study ought to be repeated but with more rider participants in the 40lbs group to determine if the 3rd horse was an anomaly or if there are other factors contributing to the horses range of motion when increasing rider weight by 40lbs.
DeleteRoost (2020) assessed pressure distribution and magnitude in horses ridden by four riders of similar ability but differing in bodyweight and height using a calibrated force mat to record pressures under the saddle in walk, trot and canter. All 13 heavy and very heavy tests and one of moderate rider tests were abandoned due to lameness and behavioural changes deemed unhealthy and unethical. This strongly suggests that rider weight had a huge effect on saddle pressures. Interestingly, only one of the moderate riders had to be abandoned. This could mean that other rider skill was not equal amongst participants, among many other possible variants such from rider balance or saddle fit to preexisting underlying conditions in the horse such as sickness or minor injury. Another limitation of this study is as that speed can alter pressure measurements, which was not controlled or recorded. Thus it was concluded that the differences in magnitude and distribution of pressures amongst the four riders varied according to their size, but may also have also been influenced by saddle fit for riders and their positions. Either way, these differences may have contributed to the development of musculoskeletal pain which will eventually lead to lameness.
DeleteCaulfield, et al (2008) conducted a study looking into the psychological effects of rapid weight loss and attitudes towards eating among a sample size of 41 professional jockeys. By using the Brunel mood scale and the Eating attitude test they were looking into the relationship between the rapid weight loss, moods and the jockey’s attitude towards food. I feel this is a good was of testing although the sample size could have been bigger to represent more of the jockey population. Both tests were conducted after 3 different events – at the jockeys minimal weight (achieved through rapid weight loss), their optimal riding weight (when they were not restricting their weight and felt healthy) and their relaxed weight (when they had no light rides or no rides) Caulfield et al hypothesised that the jockeys would have a more negative mood when compared to their moods at optimal and relaxed weights. This trend was also hypothesised for the eating attitudes as well and the results supported these. It is therefore supported that there is a negative impact on the jockey’s psychological well-being when trying to lose weight rapidly. It is suggested by many retired jockeys and doctors that the minimum weight restriction should be raised due to the fact that the lowest body fat you can get active athletes down to is about 5kg, and the lowest that has seen among 350 jockeys who have gone to John Moore’s in the last ten years was 3.7kg. The current minimum is 8st and it has been suggested by Dr George Wilson of Liverpool John Moores university that the weight should be increased to 8st7lb as to allow for the 5kg of body fat which is similar of that to Australian racing. More needs to be said about what jockeys need to do in order to reach racing weight and the Jockey Club/ BHA need to look more into the psychological effects that the jockey has to endure to make race weights. As even after the initial weigh in they do not rehydrate as they fear not making the post race weigh in. (comment from past student)
ReplyDeleteAgreed that a bigger sample size would have been beneficial, and perhaps inclusive of different sex's and ethnic backgrounds due to the differences in metabolisation between certain races. However I disagree with the idea that setting 5kg of body fat as the minimum amount should be applied to every athlete, as each body is built differently thus each body has individual limits. Nevertheless, I do again concur with the movement to increase minimum BW in jockeys to 8st 7lb. It is well known that the human race increases on av. in height with each generation (NCD Risk Factor Collaboration, 2016) and ought to be taken into consideration when adjusting weight limits, as our jockeys get taller their weight will also increase. This does not necessarily effect the body fat % that is deemed a healthy per individual.
DeleteProfessional jockeys are unique amongst weight-making athletes because they are required to make weight daily unlike other weight-limited sports.
DeleteAs such, jockeys have reported a variety of acute and chronic methods to make weight; sporadic eating, caloric restriction, diuretics, laxatives, vomiting and fluid restriction as well as regular use of sweat suits and saunas. Many of these methods could be considered dangerous as jockeys post-race weight must not be more than 1 kg different to their pre-race weight, thus those who have engaged in rapid weight loss cannot fully rehydrate prior to competition. Further studies should be done to test if this state of dehydration during a race effects riding capability. Moreover, Ryan and Brodine (2021) claimed that there is evidence to suggest that jockey training behaviours and dietary choices are not aligned with optimum preparation for the physiological demands of the sport.
A more recent study than Caulfield's et al (2008) into weight management of professional jockeys was conducted by Wilson et al (2014), who found that jockeys commonly exhibit micronutrient deficiencies, including vitamin D and calcium. It was again found that the combination of low macronutrient, micronutrient and fluid intake resulted in abnormal mood profiles and poor bone health which can impair riding performance and safety. Given the high occupational risks associated with race riding (e.g. falls and bone fractures), future research should specifically target strategies to improve bone health through the use of structured weight-bearing exercise and correcting nutritional deficiencies.
DeleteAdditionally, estimates of energy expenditure in Jockeys were found to be considerably lower than that of other sports. This suggest that conventional sports nutrition guidelines may not be applicable to the elite jockey. This suggests the need for the organisations responsible for jockey welfare to implement widespread educational programmes to assist in improving both the physical and mental well-being of professional jockeys.