How Concurrent Training Makes You a Better HYROX Athlete

Can you build strength and endurance at the same time? For decades, exercise scientists debated this question. Now, a comprehensive review of 39 peer-reviewed studies confirms: concurrent training not only works—it's optimal for hybrid sports like HYROX.

Researchers from Universidad de Zaragoza and Universidad de León conducted the first scoping review of High-Intensity Functional Training (HIFT) as it applies to hybrid competitions. Their analysis of studies from 2015-2025 provides a scientific foundation for HYROX training.

Key Finding: The "Interference Effect" is Overstated

The traditional concern with concurrent training was the "interference effect"—the idea that endurance work would diminish strength gains, and vice versa. Modern reviews of HIFT and hybrid-training studies show this fear is largely unfounded when training is structured properly.

Improvements reported across the concurrent-training literature:

Note: these ranges are typical findings across multiple studies in the field, not single-source numbers. The takeaway is qualitative — athletes who combine endurance and strength training generally achieve gains in both domains, not the strict trade-off the older "interference" view predicted.

Energy System Switching

HYROX forces your body to constantly switch between energy systems:

1. 2
   Aerobic System: Uses oxygen for sustained running efforts
2. 4
   Anaerobic System: Provides power for high-intensity stations
3. 6
   ATP-CP System: Fuels explosive movements like burpee broad jumps

The meta-analysis found that training this switching capability is itself a trainable skill. Athletes who regularly practice transitioning between systems perform better under race conditions.

The Liverpool John Moores Findings

A team at Liverpool John Moores University collated studies showing that concurrent training specifically benefits cardiovascular health through this constant switching mechanism:

"The combination of running and intense exercise that forms HYROX requires your body to switch from one energy system to another. Over time, this will have a directly positive effect on your VO2 Max and therefore performance."

One consistent finding across the research: adaptation requires commitment.

The studies showed:

• Weeks 1-3: Neuromuscular adaptations begin
• Weeks 4-6: Measurable cardiovascular and strength improvements
• Weeks 6+: Continued progression with proper programming

Athletes who stuck with concurrent training programs for at least 6 weeks saw the most significant improvements. Short-term, inconsistent training produced minimal results.

Particularly encouraging findings emerged for middle-aged and older athletes. Multiple studies from Turkey, Iran, and the United Kingdom found:

"Concurrent training has benefits for strength, muscular health, and cardio-respiratory fitness in people of all ages."

In fact, older athletes showed proportionally greater improvements in some measures, likely because they had more untapped potential in both domains.

Benefits for 40+ Athletes

The Weekly Template

Based on the research, here's an optimal concurrent training week for HYROX:

Key Programming Principles

1. Separate Conflicting Sessions

When possible, separate running and strength by at least 6 hours. If you must combine them:

• Run first if running is your priority
• Lift first if strength is your priority
• For HYROX, alternating emphasis is ideal

2. Prioritize Quality Over Volume

The research showed that 80% of adaptations come from the first 80% of optimal volume. Excessive training diminishes returns and increases injury risk.

3. Include Recovery

Studies consistently found that athletes who included structured recovery—rest days, deload weeks—progressed faster than those who trained maximally every session.

Sample 6-Week Progression

Beyond physical adaptations, the meta-analysis identified psychological benefits of concurrent training:

Improved Mental Toughness

Athletes who regularly trained both systems developed:

• Greater tolerance for discomfort
• Better pacing instincts
• Reduced perceived effort at given intensities

Variety Prevents Burnout

Switching between running and strength work reduces mental monotony. Athletes reported higher training adherence with varied programs.

The Research-Backed Approach

1. 2
   Train both systems - Don't sacrifice running for stations or vice versa
2. 4
   Commit to 6+ weeks - Short programs don't produce lasting adaptation
3. 6
   Include recovery - Deload weeks are essential, not optional
4. 8
   Practice transitions - The switching itself is a skill to develop
5. 10
   Trust the process - Concurrent training works, but requires patience

Common Mistakes to Avoid

• Training strength and endurance in the same session without recovery
• Ignoring running because you "already do cardio at the gym"
• Excessive volume without deload periods
• Expecting rapid results in less than 6 weeks

The HYROX Sports Science Advisory Council research confirms what top athletes already know: smart training beats hard training. FORMD uses these scientific insights to build personalized training plans that target your specific weaknesses.

Ready to train like the science says?

Download FORMD and discover:

• Your predicted finish time based on real race data
• Which stations are costing you the most time
• Personalized concurrent training plans built on sports science

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