Science-based Hyrox training to improve race times

Hyrox Sports Science: Getting Better and Faster

Hyrox has redefined competitive fitness by merging endurance running with functional movements. To excel in this discipline, an athlete must recognise that it is a running-focused High-Intensity Functional Training (HIFT) modality.

Scientific data from simulated competitions and professional race analytics show that running accounts for approximately 60 per cent of total race time, while the eight functional stations account for the remaining 40 per cent. Consequently, the most significant predictors of a fast finish are a high VO2max, greater weekly endurance training volume, and a lower body fat percentage.

Building the Engine: Aerobic Base Development

Because most athletes take between 60 and 90 minutes to finish, with some amateur categories extending beyond 120 minutes, Hyrox is primarily an endurance event. The metabolic demands are heavily oxidative.

Prioritise Zone 2 Training

To build a bigger engine, athletes should spend approximately 80 per cent of their running volume in Zone 2. This is defined as an intensity where the heart rate remains below the first ventilatory threshold (VT1), allowing the athlete to maintain a conversation. This training intensity promotes mitochondrial biogenesis and improves fat oxidation. Enhancing the ability to use fat as a fuel source at higher intensities is crucial, as it spares limited glycogen stores for the high-intensity bursts required during the sled push or the final wall ball set.

The 8 to 16 Week Rule

Professional coaches recommend a dedicated aerobic base-building phase lasting between 8 and 16 weeks. This period focuses on consistency and gradual increases in mileage to improve running economy and structural durability. Running economy refers to the oxygen cost of running at a given speed; improving this allows an athlete to maintain a faster pace for the same physiological effort. This phase is also essential for strengthening connective tissues to withstand the eccentric loading of the functional stations without injury.

The Role of the Aerobic System in Recovery

A highly developed aerobic system is not just for the running segments. It is the primary mechanism for clearing metabolic byproducts and regenerating phosphocreatine stores during and after high-intensity spikes. Every time an athlete transitions from a station like the Burpee Broad Jumps back to a run, the aerobic system dictates how quickly the heart rate stabilises and how quickly the athlete can return to their target race pace.

Strength and Mechanics: Powering the Stations

While endurance is the primary driver, athletes must possess the requisite strength to handle competition-standard loads efficiently. The goal is not maximal strength in a powerlifting sense, but rather “strength stamina” and biomechanical efficiency.

Horizontal vs. Vertical Force

Biomechanical studies of the heavy sled pull and sled push show that success is dictated by horizontal propulsive forces. Traditional vertical exercises like the back squat or deadlift are beneficial for general strength, but they do not perfectly replicate the mechanics of the sled. In a sled push, the angle of the torso and the ability to produce force through the ball of the foot while moving horizontally are the limiting factors. Athletes should incorporate resisted sprints or heavy sled drags to train these specific vectors.

The Interference Effect

When combining heavy strength work with high-volume endurance training (concurrent training), athletes risk the interference effect. This is a physiological phenomenon in which the molecular signalling for aerobic adaptation (AMPK pathway) can inhibit signalling for muscle hypertrophy and strength (mTOR pathway). To minimise this, it is recommended to separate strength and endurance sessions by at least 6 to 8 hours. If possible, performing strength work in the morning and running in the evening, or on separate days, allows the body to recover sufficiently to reap the benefits of both modalities.

Efficiency Over Power

Interestingly, measures like total muscle mass and hand grip strength do not show a strong correlation with overall Hyrox finish times. This suggests that metabolic efficiency and movement quality are more important than brute strength. For example, on the SkiErg and RowErg, technical proficiency and the ability to maintain a consistent power output (measured in watts) while keeping the heart rate controlled are more valuable than a high peak power output that cannot be sustained.

Strategic Pacing and Fatigue Management

Data science analysis of thousands of race results has identified specific segments where performance often degrades, commonly referred to as the point where the wheels come off!

The Mid-Race Fade

The strongest correlations with total finish time are found in mid-race running segments, specifically Runs 5-8. While many athletes feel strong in the first three kilometres, the cumulative fatigue from the Sled Push (Station 2) and Sled Pull (Station 3) begins to manifest in the middle of the race. Elite athletes differentiate themselves by maintaining a standard deviation of less than 10 to 15 seconds between their fastest and slowest running laps.

The 5th Run Trap

Studies of race data show that the 5th run is often the slowest for most participants. This run follows the Burpee Broad Jumps, which are metabolically taxing and induce significant peripheral fatigue in the quadriceps. Many athletes start the race at a pace exceeding their critical speed, entering the red zone (anaerobic territory) too early. Once an athlete crosses their second ventilatory threshold (VT2), blood lactate levels rise sharply, and the ability to recover while remaining in motion becomes nearly impossible.

Wall Ball Fatigue and Lactate Levels

The final station, wall balls, consistently records the highest heart rate, blood lactate, and relative perceived exertion (RPE). In many cases, blood lactate levels can exceed 12 to 15 mmol/L at this stage. This station has high variability, meaning it represents a major opportunity to gain or lose time. Technical proficiency—such as using the legs to drive the ball rather than the shoulders and maintaining a consistent breathing rhythm—is vital when operating under extreme physiological stress.

Performance Bio-hacking: Hydration and Tapering

Small physiological adjustments in the days and hours leading up to the race can lead to significant time improvements.

Pre-Hydration Protocol

Standard water consumption is often insufficient for a 90-minute high-intensity race in an indoor environment with limited airflow. Consuming a 1 per cent saline solution (approximately 10g of sodium chloride in 1L of water) starting 90 minutes before exercise and finishing 30 minutes before the start can boost blood plasma volume. Increased plasma volume supports better thermoregulation (cooling) and ensures more efficient oxygen delivery to working muscles. This prevents the heart rate from drifting upwards due to dehydration, a phenomenon known as cardiovascular drift.

Type IIx Overshoot and Tapering

A properly structured taper, typically lasting 7 to 14 days, involves a significant reduction in training volume while maintaining intensity. This allows the body to repair micro-trauma and replenish glycogen stores. More importantly, it facilitates a transition in muscle fibre phenotypes. During periods of high-volume endurance training, explosive Type IIx fibres often shift toward more oxidative Type IIa characteristics. A taper allows these fibres to transition back to a faster, more powerful phenotype. This leads to a Type IIx overshoot, providing the athlete with more explosive power during the functional stations than they had at the peak of their training block.

FAQ

What is my target Hyrox running Pace?

Scientific data indicates that the average pace of the 8km running portion of Hyrox correlates most closely with an athlete’s flat Half Marathon pace. Although the running distance is shorter, the functional stations elicit high blood lactate levels and maintain heart rate above the lactate threshold (VT2). This physiological stress, combined with the peripheral fatigue from movements like the sled push and burpees, reduces running economy to a level where the sustainable pace for the 1km segments matches the intensity of a 21.1km road race.

Is my HM Race time likely to be faster or slower than my Hyrox time?

“It depends,” is the obvious answer. However, here are typical performances that align with my personal experience as a stronger runner than a strength athlete.

What Race Day Supplements Work?

Summary of Training Focus

Building a Hyrox performance requires a solid base.

The aerobic base is the foundation; if it is weak, the visible structure—the speed and strength—will crumble in a race. A solid foundation of Zone 2 running and metabolic efficiency allows the athlete to utilise their strength on the stations without entering a state of irreparable fatigue.

Sources

• Box Nutrition
• Triage Method
• Warrior Performance Lab
• r/Hyrox (Reddit Hydration thread)
• Roxlyfe
• Hyrox SSAC Report
• Acute Physiological Responses in Hyrox (Frontiers in Science)

Sports Tech tools for Hyrox

I use and recommend all the following products. I am a decent age group triathlete and do Hyrox training ‘for fun’.

• Muscle Oxygen Sensor to determine fatigue – Train.Red or Moxy
• A non-GPS pacing device for the run – Stryd footpod is super accurate in the arena, but may interfere with rowing straps, a calibrated Garmin HRM 600 may provide reasonably accurate pace and accurate heart rate.
• A watch to display progress (time), current effort (heart rate), pace/speed. Garmin’s best lightweight multisport watch is the Forerunner 970, Apple Watch Ultra 3 can be used. Amazfit Active Max is a cheap bit of tech with a dedicated Hyrox mode
• Garmin/Apple probably require the Roxfit app to act as anything other than a glorified stopwatch.

Last Updated on 10 March 2026 by the5krunner

the5krunner

tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors.