What We’ve Learned From 10 Rucking Studies and Research Reviews at MTI

By Rob Shaul, Founder

1. Case Study – 46-Year Old Army Officer

Plan: MTI’s Max Effort Strength + 6-Mile Ruck Improvement Plan
Length: 7 Weeks

Results:

• 14% average increase in strength (back squat, bench, hinge, pull-ups)
• 14% improvement in 6-mile ruck time

Training Takeaways:

• Afternoon training yielded better joint readiness.
• Saunas helped with recovery.
• Waist belt significantly improved ruck performance.

Ruck Interval Strategy: 2-mile intervals were the most effective ruck sessions—progressed from walk-run to full run at Zone 3 .

2. Mini-Study: Apex Fitness Standards

Plan: 3.5-week, 6-day/week cycle targeting back squat, pull-ups, push-ups, 1-mile run, and 6-mile ruck

Results:

• All 5 participants improved across all fitness domains.
• Strongest gains seen in strength and bodyweight endurance.
• 6-mile ruck times improved despite intense overall training volume.
• Best performers narrowly missed or met MTI’s elite “Apex Standards.”

Conclusion: Concurrent improvement across multiple domains (strength + endurance) is achievable with focused, assessment-based training .

3. Mini-Study: Loaded Step-Ups vs. Ruck Speed

Plan: 3.5 weeks of loaded step-up intervals

Results:

• Step-ups improved 15.9%, but only 6% improvement in 3-mile ruck time
• Improvement in ruck time likely due to test familiarity, not training transfer.

Conclusion: Loaded step-ups do not transfer well to ruck speed. Mode-specific training (i.e., rucking) is superior .

4. Mini-Study: Strength vs. Hybrid vs. Endurance for Ruck Speed

Plan: 5-week training, 3 groups

• Group A: Strength-heavy
• Group B: Hybrid (balanced strength & endurance)
• Group C: Endurance-heavy

Results:
– Hybrid (9.4%) and Strength (8.5%) outperformed Endurance (3.2%) in ruck speed gains
– Strength gains were not the sole reason; likely better recovery and less fatigue in strength/hybrid groups

Conclusion: Endurance-only programming underperforms for improving ruck speed. Hybrid or strength-emphasis models are superior .

5. Mini-Study: Threshold Intervals vs. Long Ruck for Speed

Plan: 3 weeks

• Group A: 1-mile intervals only (2x/week)
• Group B: Intervals + 1 long moderate pace ruck/week

Results:

• Group A improved by 8%, vs Group B at 2%
• Twins used as matched pair—interval-only twin outperformed

Conclusion: For short-distance ruck speed, threshold intervals (1-mile repeats) are significantly more effective than adding a long, slower ruck .

6. Mini-Study: 2:1 Run-Walk Interval vs. Continuous Ruck

Plan: Crossover test with 4 athletes, 6-mile ruck @ 60#

Results:

• 2:1 strategy faster on average (1:20 vs. 1:23.75)
• Subjectively easier—reduced perceived effort and mental fatigue

Conclusion: 2:1 run-walk intervals are not only faster but more mentally sustainable, challenging assumptions about continuous ruck being optimal .

7. Research Review: Fatigue and Gait Changes

Study: 7+ mile ruck march with IMUs (82nd Airborne, n=70)

Findings:

• Fatigue shortened stride length, increased stride width and variability
• Increased torso sway, indicating less trunk control under fatigue

Implications:

• Fatigue clearly alters biomechanics and may increase injury risk
• Real-time sensors are viable for field monitoring .

8. Research Review: Predictors of 12-Mile Ruck Success

Study: ROTC cadets (n=65) with 35-lb ruck

Key Predictors of Completion:

• Fat-Free Mass (FFM): +1 kg = 24% higher odds
• 2-Mile Run Score: Strongest predictor; +1 point = 9% increased odds
• ACFT Score: +1 point = 6.1% higher odds
• BMI and weight NOT predictive

Conclusion: Ruck performance is best predicted by aerobic fitness and lean mass—not weight, BMI, or power .

9. Ruck Deep Dive #1: Physical Attributes That Predict Rucking

Study: ROTC Cadets (n=46), 10km ruck @ 29kg

Findings:

• Best single predictor for men: 2-mile run (34%)
• For women: Height (82%)
• Combined measures (e.g., 2-mile run + sit-ups) predicted ruck performance better
• Upper body strength more relevant than lower body (relative bench press > squat)

Conclusion: Ruck performance is multifactorial—cardio, size, and relative strength all play roles .

10. Ruck Deep Dive #2: Best Ways to Improve Rucking

Plan: 6-week training plan, analyzed impact of strength and endurance

Key Findings:

• Strength gains (especially upper body) had the biggest impact
• rior studies focused too much on VO2 max; under-load strength matters more for real-world rucking
• Minimum strength threshold likely exists—below which strength is the limiting factor

Recommendations:

• Males: Prioritize strength if weak; if strong, shift to aerobic.
• Females: Start with lower body strength; then core and aerobic fitness

Conclusion: Build foundational strength before focusing on endurance to maximize ruck improvement .

Takeaways Across All Studies

• Strength + Hybrid Ruck Training > Endurance Only Ruck Training
• Threshold Intervals > Long Slow Distance Rucking
• 2:1 run-walk intervals outperform continuous ruck running
• Specificty wins … rucking > step ups to improve rucking performance
• Fatigue degrades rucking gate
• Best ruck predictors = aerobic fitness + lean mass

Programming Implications

• Build strength first. If the athlete is weak, aerobic work has limited benefit.
• Use 1- and 2-mile ruck intervals to increase speed and reduce mental fatigue.
• Run-walk intervals (2:1) improve pacing sustainability for long-distance rucks.
• Assess fitness via 2-mile run and body comp. These are reliable predictors.
• Avoid over-relying on step-ups or general endurance movements—mode-specific work is more effective.

Final Thought

MTI’s ruck studies show that strength matters more than commonly believed. Athletes under load are limited not by VO2 max alone, but by their ability to handle and move with weight over distance. If you want to get better at rucking—train to ruck, build strength, and don’t overlook pacing strategies.

Have questions or want programming advice?  Email us: coach@mtntactical.com