Feeding Eventers: Managing Energy Across Disciplines

Why Feeding Eventers Is Uniquely Challenging

Eventing is often called the triathlon of the equestrian world, and for good reason. Your horse needs the controlled suppleness and calm focus of a dressage horse, the explosive stamina and bravery of a cross-country machine, and the careful precision of a show jumper — sometimes all within the same day or weekend.

From a nutritional standpoint, this creates a genuine puzzle. Each discipline draws on different energy systems, different muscle fibre types, and different mental states. A feed plan that produces a calm, rideable dressage horse might leave you short on fuel for cross-country. A diet that powers your horse through a demanding cross-country course might make dressage feel like riding a firecracker.

Feeding eventers well means understanding how energy works in the horse's body, matching fuel sources to the demands of each phase, and making smart adjustments throughout the competition season.

Understanding Energy Systems in the Event Horse

Before diving into feed plans, it helps to understand the two primary energy systems your event horse relies on:

Aerobic Energy (Slow-Burn Fuel)

Aerobic metabolism uses oxygen to convert fats and fibre into energy. This system powers low-to-moderate intensity work — flatwork, hacking, warm-ups, and sustained canter work. It produces energy slowly and steadily without generating excessive lactic acid.

The main dietary sources of aerobic energy are:

• Fibre (hay, haylage, chaff, beet pulp)
• Fats and oils (vegetable oil, linseed, rice bran)

Anaerobic Energy (Fast-Burn Fuel)

Anaerobic metabolism kicks in when your horse needs bursts of power — galloping uphill on cross-country, powering over a big spread fence, or accelerating out of a combination. This system primarily uses glycogen (stored carbohydrates) and works without oxygen, but it produces lactic acid as a by-product, which contributes to fatigue.

The main dietary sources of anaerobic energy are:

• Starch and sugars (cereal grains like oats, barley, and maize)
• Glycogen reserves built up through training and appropriate feeding

Eventing requires both systems working together, which is what makes the nutritional balance so critical.

Matching Feed to Each Discipline

Dressage: Calm Focus and Controlled Energy

Dressage demands relaxation, suppleness, and responsiveness. You want your horse working through his back with a calm mind — not jig-jogging around the warm-up arena because he's fizzing on grain.

For the dressage phase, your horse benefits from a diet that emphasises:

• High-quality fibre as the foundation (good hay or haylage)
• Oil-based calories for sustained energy without excitability
• Moderate starch levels to avoid spiky behaviour

Horses that become tense or excitable on high-grain diets often settle dramatically when calories from cereal grains are partially replaced with oil and super-fibres like beet pulp or soy hulls. A tablespoon of oil provides roughly the same energy as a handful of oats — but without the blood sugar spike.

Cross-Country: Stamina, Speed, and Recovery

Cross-country is where your feeding strategy faces its biggest test. Your horse needs enough glycogen reserves to sustain a galloping effort over several minutes, jump boldly, and recover quickly afterward.

Key nutritional considerations for cross-country include:

• Adequate glycogen stores — built over days and weeks through appropriate starch intake in training, not by loading grain the night before
• Sufficient fat adaptation — horses trained on higher-fat diets become more efficient at using fat for fuel, sparing glycogen for when it's truly needed
• Electrolyte balance — sweating during cross-country depletes sodium, chloride, potassium, and magnesium. These need replacing before, during, and after competition
• Hydration — a dehydrated horse cannot perform or recover properly

Research has shown that horses conditioned on diets containing added fat (typically 6-10% total dietary fat) perform better in prolonged exercise tests because they use glycogen more sparingly. This "glycogen-sparing" effect is one of the most powerful nutritional tools available to event riders.

Show Jumping: Precision and Power

Show jumping after cross-country tests your horse's ability to recover and still produce careful, athletic jumping. By this point, glycogen stores may be partially depleted, muscles may be fatigued, and hydration status is critical.

Nutritional support for the show jumping phase focuses on:

• Rapid rehydration after cross-country
• Electrolyte replacement to support muscle function
• Easily digestible forage access between phases
• Avoiding large grain meals close to jumping, which divert blood to the gut

Building a Feeding Plan for the Event Horse

Step 1: Establish the Fibre Foundation

Regardless of your horse's level — BE80 or five-star — forage should make up at least 1.5% of bodyweight daily, and ideally closer to 2%. For a 500kg horse, that's 7.5-10kg of hay or haylage per day.

Forage provides slow-release energy, supports gut health, and acts as a water and electrolyte reservoir in the hindgut. Never restrict forage to "keep weight down" without first evaluating total caloric intake. A horse heading into cross-country on a half-empty hindgut is at a disadvantage.

Step 2: Add Calories Strategically

Once forage needs are met, add concentrated energy based on your horse's workload, body condition, and temperament:

For most eventers, a combination of super-fibres, oil, and moderate cereal grain works well. The ratio shifts depending on the individual horse.

Step 3: Manage Starch Wisely

Starch is not the enemy — your event horse genuinely needs some dietary starch to maintain glycogen stores, especially at higher levels. But how much and when matters enormously.

Guidelines for starch management:

• Keep individual starch meals below 1g of starch per kg bodyweight (so under 500g of starch per meal for a 500kg horse)
• Split hard feeds into 2-3 smaller meals per day
• Feed the highest-starch meal at least 4-6 hours before intense exercise
• Choose processed grains (cooked, micronised, or extruded) for better digestibility
• Avoid feeding large grain meals within 3 hours of competition

Overloading starch in a single meal overwhelms the small intestine's capacity to digest it. Undigested starch spills into the hindgut, disrupts the microbiome, and increases the risk of colic, laminitis, and hindgut acidosis.

Step 4: Don't Forget Micronutrients

Energy gets all the attention, but vitamins and minerals are the unsung heroes of performance. Event horses have increased requirements for:

• Vitamin E and selenium — powerful antioxidants that protect muscles from exercise-induced oxidative damage
• B vitamins — involved in energy metabolism (usually synthesised by hindgut bacteria, but supplementation may help horses under heavy work)
• Iron, copper, and zinc — essential for oxygen transport and tissue repair
• Calcium and phosphorus — bone remodelling is constant in horses doing concussive work

Analysing your horse's diet is the most reliable way to identify gaps in micronutrient intake. Many horse owners are surprised to find that their feed plan provides plenty of calories but falls short on key vitamins and minerals — especially when relying heavily on straights like oats or basic chaff without a balancer.

Step 5: Adjust for Competition Week

Smart feeding adjustments in the days around competition can make a meaningful difference:

3-5 days before:

• Ensure electrolyte levels are topped up (don't start supplementing the morning of — it takes days to fully rehydrate tissues)
• Maintain normal feeding routine — drastic changes cause digestive upset
• Ensure ad-lib access to water and salt

Day of competition:

• Feed a normal forage-based breakfast, but reduce or eliminate hard feed within 3 hours of the first phase
• Offer small hay nets between phases
• Provide water at every opportunity
• Administer electrolytes according to expected sweat losses

After cross-country:

• Cool the horse properly, then offer water in small amounts frequently
• Provide electrolytes to replace sweat losses
• Offer soaked hay or a small bran/beet mash
• Return to normal feeding in the evening

24-48 hours after:

• Keep forage intake high to support gut recovery
• Reduce hard feed slightly if the horse is resting
• Monitor for signs of tying-up, dehydration, or poor appetite

Electrolytes: The Performance Factor Most Riders Underestimate

Sweat losses during cross-country — especially in warm weather — can be substantial. A horse can lose 10-15 litres of sweat during a hard cross-country run, and equine sweat is hypertonic, meaning it contains more electrolytes than blood plasma.

Lost electrolytes must be replaced. Plain water alone won't do it. Key electrolytes to supplement include:

• Sodium chloride (salt) — the most important and most commonly deficient
• Potassium — usually adequate in forage-based diets but can be depleted with heavy sweating
• Magnesium — supports muscle relaxation and nerve function

A baseline of 1-2 tablespoons of plain table salt daily covers maintenance needs. During competition, use a properly formulated electrolyte paste or powder that contains sodium, chloride, and potassium in physiologically appropriate ratios. Avoid products loaded with sugar and low in actual electrolytes.

Common Feeding Mistakes With Event Horses

1. Over-reliance on cereal grain

Piling in oats or mix to fuel cross-country while making the horse unrideable in dressage. Shift toward oil and super-fibres for calmer, more sustained energy.

2. Neglecting forage quality

Poor-quality hay means your horse misses out on baseline energy and fibre. Invest in the best forage you can source — it's the single most impactful feeding decision you can make.

3. Last-minute dietary changes

Switching feeds or adding supplements the week of a competition is a recipe for digestive upset. Make all changes gradually over 10-14 days.

4. Ignoring body condition between events

Monitor your horse's weight and condition regularly. Event horses in heavy work can drop condition quickly. Conversely, horses doing less work between events can gain weight if feed isn't adjusted.

5. Skipping the maths

Guessing at quantities leads to over- or under-feeding. Weigh your feeds, calculate your horse's energy and nutrient intake, and compare it to established requirements. If you're not sure where to start, analysing your horse's diet takes the guesswork out of the equation.

Putting It All Together

Feeding an event horse is about finding the sweet spot — enough energy to perform across three demanding disciplines, delivered in the right form, at the right time, without compromising health or temperament.

The core principles are straightforward:

1. Forage first, always. Build the diet on excellent hay or haylage.
2. Use fat for stamina. Oil and high-fat feeds spare glycogen and keep horses calmer.
3. Use starch wisely. It's necessary for glycogen, but manage amounts and timing carefully.
4. Replenish what sweat takes away. Electrolytes and hydration are non-negotiable for performance and recovery.
5. Balance the whole diet. Energy without adequate vitamins and minerals is like fuel without engine oil — it won't end well.

Eventing asks extraordinary things of our horses. The least we can do is fuel them properly for the job.