The small study, by researchers from Duchy College in Cornwall, assessed 152 horse and their adult riders in the Devon and Cornwall region, to see how many matched veterinary guidelines that state a rider should weigh less than 10 per cent of their horse's weight.
According to the scientists behind the research, only five per cent of riders fell within those guidelines. In fact, 32 per cent weighed in at more than 15 per cent of the weight of their equine friend, with the remaining 63 per cent hitting a 'satisfactory' level between 10 and 15 per cent.
Carrying too heavy a rider poses serious health risks for horses who, despite their size, can quickly develop problems such as back pain and lameness, and behavioural problems like bucking and rearing sometimes follow as a result.
She added: "It is definitely a potential welfare issue. These are broad-brush guidelines. They don't take account of all factors, such as the age of the horse, the breed, the style of riding or the experience of the rider."
Keith Chandler, president of the British Equine Veterinary Association, agreed, saying many of the lameness and back problems dealt with by vets in the UK were caused by "the wrong riders on the wrong horses".
He told the Daily Mail: "Many riding schools are very aware of these problems and exactly who can ride which horses and who cannot, but there are some horse people who may not fully understand the issues.
"There is a discussion which needs to take place in the horse riding community. There needs to be an awareness that some larger riders need to ride bigger horses."
What do you think? Should more be done to make British riders aware of the weight guidelines? Leave your comments below...