By Emmett Shaul, MTI Coach
BLUF
To kick off the new year, we are conducting a 4-Week Mini Study using our internal Lab Rats at the Wyoming lab to test four specific questions regarding transferability and work capacity:
- Trap Bar Transfer: Does a density based Trap Bar Deadlift progression increase 1RM strength for the Hinge Lift and Back Squat?
- Pressing Transfer: Does a Military Press progression transfer strength gains to the Bench Press?
- Sled Push Capacity: Do sled pushes improve general work capacity and conditioning, or does the adaptation only improve sled push proficiency?
- Chassis Integrity: Can we progress the “Good Morning” and “Standing Russian Twist” using a modified Big 24 strength progression, rather than our standard fixed weight durability protocols?
Background
Trap Bar Deadlift: The Hybrid King? The Trap Bar Deadlift (TBDL) has gained massive popularity in tactical fitness, evidenced most significantly by the U.S. Army’s adoption of the 3-Repetition Maximum TBDL for the Army Combat Fitness Test (ACFT), and recently the AFT. The Army’s rationale focused heavily on safety and biomechanical efficiency, citing reduced lumbar stress compared to the straight bar (Myers, 2018).
From a physiological standpoint, the TBDL is often considered a mechanical hybrid between the traditional Hinge Lift (Deadlift) and the Back Squat. Research indicates that while the TBDL is a hinge-dominant movement, it elicits significantly greater quadriceps activation (vastus lateralis) than a straight bar deadlift, while placing less stress on the lumbar erectors (Camara et al., 2016; Swinton et al., 2011).
This cycle we want to test the “middle ground” nature of the trap bar dead lift, and if effectively drives strength improvements in the two lifts it mimics (back squat and deadlift), or if the lack of specificity limits its transferability.
Military Press vs. Bench Press The relationship between vertical and horizontal pressing strength is well-debated. While the Bench Press is the standard metric for upper-body pushing strength, it lacks the core stability demands of the overhead Military Press. We are investigating the “transfer” effect: if we focus exclusively on driving up the Military Press numbers, will the strength gained in the deltoids and triceps—combined with increased shoulder girdle stability—transfer to a higher Bench Press 1RM?
Sled Pushes: General Conditioning or Specific Adaptation? Current literature on sled pushes has moved beyond just sprint mechanics; several studies suggest that heavy sled work significantly increases lower body strength and horizontal force production (Maddigan et al., 2014). However, we’re interested in this cycle on developing a standardized method to use sled push repeats to train work capacity, a way to progess that method, and the transferability of sled pushing to other work capacity modes.
We have previously explored sled dynamics in two mini-studies with compelling results:
- Backwards vs. Forward Sled Drags: In a 2017 study, we compared two groups performing heavy sled drags—one exclusively moving backwards, the other forwards. The results showed that both groups achieved nearly identical improvements in lower body strength (Front Squat/Hinge Lift 1RM) and Work Capacity (shuttle sprints). This suggested that the direction of the drag was less important than the intensity of the load.
- Forward Sled Pulls for Maintenance: In a 2018 study, we investigated if heavy sled pulls alone could maintain leg strength in the absence of barbell squatting. After 4 weeks of only sled pulls, Lab Rats not only maintained their strength but saw slight increases in their Front Squat and Hinge Lift 1RMs. This validated the sled as a legitimate strength tool, not just a “finisher”.
Sleds are no joke. The metabolic demand is incredibly high. Building on our previous findings, we are testing sled pushes strictly as a metabolic conditioning tool. We don’t know if they are broadly effective for conditioning outside of the event itself. I want to see if this functions as a viable work capacity mode, or if the adaptation is too specific to the apparatus.
Chassis Integrity: Fixed Load vs. Progressive Strength Historically, MTI Chassis Integrity programming has revolved around using standard, fixed weights—typically 40lb or 60lb sandbags and fixed plate weights—for circuits involving the Standing Russian Twist, Dumbbell Pass Through, and Kneeling Plate Half Moon. These are traditionally fixed-load durability efforts.
However, fixed loading is problematic due to the nature of our athlete population. For our bigger and stronger athletes, the standard fixed weight could be too light.
For this cycle, we are testing the viability of a modified Big 24 progression on the Good Morning, Standing Russian Twist and Weighted Situp. The primary goal is to determine if we can safely increase raw chassis strength by scaling the load to the individual, rather than just chassis durability at a fixed load.
Cycle Design
Trap Bar Deadlift Study
- Week 1: 1RM Assessment: Hinge Lift, Back Squat, Trap Bar Deadlift.
- Weeks 2-3: 3x/Week Density Progression for Trap Bar Deadlift.
- Week 4: Re-Test 1RM: Hinge Lift, Back Squat, Trap Bar Deadlift.
Military Press Study
- Week 1: 1RM Assessment: Bench Press, Military Press.
- Weeks 2-3: 3x/Week Density Progression for Military Press.
- Week 4: Re-Test 1RM: Bench Press, Military Press.
Sled Push Work Capacity
- Week 1:
- Assessment: Max Reps 3-Minute Prone-to-Sprint.
- Work: 2x/week 8-Round Sled Push Intervals (30 sec Work : 60 sec Rest).
- Week 2: 2x/week 11-Round Sled Push Intervals (30:60).
- Week 3: 2x/week 14-Round Sled Push Intervals (30:60).
- Week 4: Re-Assessment: Max Reps 3-Minute Prone-to-Sprint.
Chassis Integrity
- Week 1: Tuesday: Find 10RM Good Morning, 5RM Standing Russian Twist, 10RM Weighted Sit Up. Friday: 5 Rounds @ 10RM/5RM – 10# Loads
- Week 2: 2x/week 5 Rounds @ 10RM/5RM loads (-10# and -5# 10RM/5RM loads)
- Week 3: 2x/week 5 Rounds @ 10/5RM loads (-5# and at 10RM/5RM loads)
- Week 4: Re-Assessment.
Final Thoughts
I am confident that the Trap Bar Deadlift will increase our Hinge Lift 1RMs due to the similar hip-extension mechanics. I am less confident regarding the Back Squat transfer; while the TBDL recruits quads, the range of motion does not equal a full-depth squat. If the TBDL drives squat numbers up, it could arguably become the ultimate “minimum effective dose” lift for tactical athletes.
Regarding the Sled Push: We know sleds are hard, but we don’t know if they are broadly effective for conditioning outside of the event itself. I want to see if this functions as a viable work capacity mode, or if the adaptation is too specific to the apparatus.
Finally, for Chassis Integrity, we are venturing into new territory by applying strength progressions to movements we usually treat with volume. I am interested to see if a modified Big 24 progression is sustainable for these movements and if it produces a noticeable difference in core stiffness and strength. The “unknown” here is the field transfer—will a stronger chassis in the gym translate to better durability in the field? That is difficult to test quantitatively, but the first step is determining if we can program these movements for strength rather than just durability.
References
Baumann, M. A. (2022). An investigation of the Sled-Push Exercise in Older Adults: Physiological Quantification, Perceived Enjoyment and Body Discomfort (Doctoral dissertation, Northern Illinois University).
Camara, K. D., Coburn, J. W., Dunnick, D. D., Brown, L. E., Galpin, A. J., & Costa, P. B. (2016). An examination of muscle activation and power characteristics while performing the deadlift exercise with straight and hexagonal barbells. The Journal of Strength & Conditioning Research, 30(5), 1183-1188.
Myers, M. (2018). ACFT: Practical, Feasible, Safe? NCO Journal. Army University Press.
Swinton, P. A., Stewart, A., Agouris, I., Keogh, J. W., & Lloyd, R. (2011). A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads. The Journal of Strength & Conditioning Research, 25(7), 2000-2009.