“It's surprising to see that a small change can have such a major impact”
Young Friesian stallions benefit from a more varied training schedule with regular downtime.
In some cases, horses actually develop stamina more quickly by training a bit less. This was the remarkable outcome of a study by veterinarian Esther Siegers and sports physiologist . They studied the effects of a modified and lighter training schedule for young Friesian stallions during performance testing for the Friesian horse studbook.
The Friesian Horse Studbook (KFPS) invited Carolien Munsters to assess the ‘performance test’ training programme for Friesian stallions three years ago. The programme hadn't been reviewed or adjusted for years. Each year, a select group of young stallions take part in the performance test in order to qualify as studbook stallions. The stallions are brought to a designated training site where they are trained for a period of seven weeks and assessed in order to determine their physical ability as riding and driving horses and evaluate their character and health. The best stallions are eventually selected as breeding stallions and can then pass on their genes to future foals.
A fresh perspective
“There were already signs that the performance test might be too tough for the young Friesian stallions,” Munsters explains. “Some stallions weren't managing to keep up well and there were also some injuries. I welcome this initiative by the Friesian studbook. The equestrian world is quite traditional, and you really need a fresh perspective to figure out if the way you've always been doing things is actually the best option.” Munsters specialised in equine sports physiology after her Master's degree in medical biology, and obtained her PhD on the same subject from the Faculty of Veterinary Medicine. She conducted the study in collaboration with her PhD student Esther Siegers, European specialist in equine internal medicine at the Faculty of Veterinary Medicine.
They first started monitoring the stallions' condition during standard performance testing in 2020, gathering data on the length, frequency and duration of the training sessions and conducting various physiological measurements. The stallions were subjected to three separate exercise tests consisting of four minutes of walking, four minutes of trotting and two two-minute canters, all while being ridden. Siegers: “The horses were wearing a heart rate monitor and we used the stopwatch to make sure they performed the exact same procedure in every test. After the trot and gallop, we took blood samples to measure whether there had been more muscle acidification, which we refer to as lactate levels. As the horse's fitness improves, there will be less lactate in the blood when it exerts the same amount of effort.”
Overtrained stallions
As the measurements showed, the young Friesian stallions' physical condition actually deteriorated rather than improved during training. Their heart rate remained higher and lactate levels increased during the same exercise. The horses had more difficulty completing the same test as time went on. This suggested they were being overtrained.
Feedback from the riders revealed that they hardly noticed the horses' growing fatigue. Munsters: “It's also not necessarily the case with every horse. A Friesian horse will keep going for a very long time, even though they might already reach high lactate levels after relatively light activity - say, two minutes of galloping - and feel tired. These horses are bred for their character: they want to keep working. The problem is, that means we can't always tell whether the horse is tired.”
Modified training programme
The researchers presented their results to the studbook and recommended a modified training programme. Siegers: “The people at the studbook responded enthusiastically, and invited us to make recommendations.” The new training programme was designed to offer more variety. The horses went from an average of five training days per week to three proper workouts alternated with gentle recovery workouts. On those days, the horses did light exercise in the form of lungeing (long rein), calm exercise in the riding arena without any cantering or a gentle ride through the forest. There was less cantering overall, as this proved especially demanding for the young Friesian horses.
The new training programme was used during the 2021 performance test and the researchers monitored the stallions' condition again using the same procedure and three rounds of testing. Siegers: “This time, the measurements showed that the stallions' condition was actually improving rather than deteriorating.! The stallions were getting fitter over the course of the examination.”
Friesian stallions want to keep working, so we can't always tell whether they're tired.
Structure is key
Although the researchers had expected similar results on the basis of their scientific knowledge, they were pleasantly surprised. Siegers: “It was surprising to see that a minor adjustment to the training programme could have such a huge effect.” As the results show, the structure of training programme is key. Munsters: “You get the best results if you accurately tailor the training programme to the horse's physical capacity. If you train them just above that level at certain times and give the horses enough recovery time between training stimuli, you'll be able to maximise the physiological supercompensation mechanism (see box). The body can then adapt properly, yielding optimal results. If you train them too hard or too often, their body won't be able to recover enough and their fitness will deteriorate.”
The better you train them, the more they can work
So do these results apply to other horse breeds, like warmbloods and thoroughbreds? Siegers: “Studies have shown that warmbloods have more endurance than coldbloods like Friesians, but the training concept remains the same. If you want to improve their fitness, you'll need to do a short but slightly more intense workout two or three times a week and complement that with recovery training and free movement. The more trained the horse is, the more work it will be able to do even during more intensive training sessions and recovery workouts.”
Munsters: “Riders can't always tell just how much the horse can take. This is why I always recommend that they regularly ride with a heart rate monitor. That's really the best approach if you're serious about training and want to gradually increase your horse's capacity.”. Siegers: “You should also monitor how long and intensively you ride, using an app, for example. When people go running, they also tend to use a training schedule. You only run a few minutes more each week in order to avoid any injuries. We should be using the same approach for horses.”
The supercompensation mechanism during training sessions
Every body has a specific baseline fitness level. If you train a tiny bit longer or more intensely than usual, you're temporarily bringing your body off balance. That imbalance then triggers the body to adapt and improve. The body will start to restore this balance in the post-exercise period and subsequently adapt so that your tissue can temporarily tolerate a tiny bit more than it could before the training stimulus. This is referred to as the supercompensation phase. If you add a new training stimulus at this exact stage, your fitness level will improve. If you wait too long to start training, the tissue will return to its original level and you won't progress. If you start training too soon, the tissue won't be able to recover properly. If you start training too soon, too frequently and over a long period of time, you are liable to overtrain and your fitness level will deteriorate.