Winning Collisions with Power
Summary
The time frame that decides whether collisions are won or lost ranges typically between 300 and 500ms. It is mechanical power that is the defining athletic quality. Here is how horizontal force-velocity profiling and the DynaSled change what we can measure and train.
Advancing through — not around — a defence is the primary attacking principle in rugby and football codes. Playing through a defensive line is largely won with momentum. Mass is certainly a factor, but for primary ball carriers the decisive variable is their ability to accelerate their own mass, and then the mass of whoever is in front of them. Collisions are won, lost, or neutral. The question worth pursuing is how positive outcomes can be achieved reliably, and what the physical and technical underpinnings of that capability actually look like.
The 300–500ms Window
The timeframe within which collision outcomes are typically decided is 300–500ms. That is not a strength window. It is not a technique window in the conventional sense either. It is a power window — the capacity to produce force rapidly, within a very short and non-negotiable timeframe.
This has a meaningful implication for training: Olympic lifting and its derivatives, which are built on the same temporal and mechanical demands, provide an excellent basis for developing this quality. The research of Dan Baker, one of the more practically rigorous contributors to strength and power programming in team sports, illuminates a useful benchmark. Optimal power training loads sit at approximately 50% of an athlete’s maximum strength. From this, Baker’s work suggests that to move a defender of comparable body mass at 1 m/s or greater within that 300–500ms collision window, a ball carrier needs to be able to back squat at approximately 1.8–2 times body mass.
The practical takeaway is deceptively simple: as a first approximation, a player’s ability to win a collision can be benchmarked against how fast they can move their own body mass as an external load. That standard holds reasonably well across a range of Olympic lift derivatives.
What the Gym Doesn’t Capture
Physics is only half the story. The other half is perceptual and locomotor skill — and this is where practitioners need to be careful about the assumptions they make.
I recall a sharp exchange in 2017 with Eddie Jones, then England Head Coach. I had cited the strength and power metrics of one of the prominent forwards, and his response was immediate: “He’s not powerful on the field.” He was right. A player can hold impressive numbers in a gym environment and still fail to express that capacity in a collision context. The disconnect is real, and it matters.
Power on the field can be assessed quantitatively:
- Individual metres gained in attack
- Post-contact metres gained (team-level indicator of collision dominance)
- Speed and acceleration into contact, tracked via GPS
From a qualitative standpoint, the open skills of perception and locomotion play an equally significant role. How a player interacts with the ground at the moment of impact — the timing and coordination of ground force application — can determine the outcome of a collision irrespective of raw power qualities. A player who is poorly timed or mistimed at contact will be driven backwards or rotated, regardless of what they can move in the gym. The principle here is straightforward: you cannot accelerate another mass if you are in the air at the moment of contact.
This maps cleanly onto what we observe in world-class sprint mechanics. Elite sprinters spend approximately 80% of the contact period in the first three steps out of the blocks on the ground — and it is precisely within those ground contact periods that force is produced, redirected, and expressed as acceleration. The same physics governs contact sports.
Why Dynamic Correspondence Matters
The holistic profiling of primary ball carriers requires the integration of two distinct knowledge domains: the tactical and technical, and the physical. The right blend of open (perceptual, reactive) and closed (trained, repeatable) skills. This is why the working relationship between the positional coach and the athletic performance coach is not just professionally useful — it is mechanically necessary.
That said, it is worth acknowledging a structural limitation in traditional strength and power training. These modalities are largely uniplanar and non-locomotive. Squatting, deadlifting, and even many Olympic lifts are executed from a fixed base, without the balance, coordination, and reactive demands that are present in running and collisions. This limits their dynamic correspondence — the degree to which training transfers to the target movement.
Horizontal mechanical power training offers a meaningful extension here. Because it involves the full coordination and postural reflexes of running mechanics, it carries considerably greater dynamic correspondence to the demands of field-based contact sport.
What Horizontal Force-Velocity Profiling Adds
JB Morin’s work on horizontal force-velocity profiling provides a useful lens through which to interpret collision capacity — and it offers an interesting comparison to the vertical and bilateral strength standards established by Baker and colleagues.
One of the notable findings from the horizontal profiling literature is that the sled load which typically elicits maximal horizontal power output produces approximately a 50% reduction in velocity over short distances, compared to unloaded sprint acceleration. The athlete is working at peak power, but at the cost of half their normal speed. Interestingly, elite-level benchmarks within horizontal power modalities again converge on a recognisable standard: body mass at a given velocity. Own-body-mass as an external load at a target speed is a consistent reference point across both vertical and horizontal assessment frameworks.
What horizontal profiling adds is directional specificity. Rather than inferring horizontal power output from vertical or bilateral measures, it assesses it directly — and in doing so, it clarifies what specifically limits each individual player’s capacity to win collisions. The profile distinguishes between athletes who lack force production and those who lack the mechanical efficiency to orient and apply the force they do produce.
Three Distinct Profiles
This is where the DynaSled, by Swift Performance, becomes directly relevant. As a friction-resistance sled — producing measurable, precise load data across the full acceleration effort — it allows simultaneous training and profiling of horizontal mechanical power. The technology is capable of directing players into three distinct categories:
Force development — effective acceleration mechanics are in place, but absolute power output is insufficient. The limiting factor is the magnitude of force produced.
Force orientation — power output is adequate, but the direction of force application is inefficient. The athlete has the engine but is not pointing it in the right direction.
Both — mechanics and force production both require development. The athlete needs a more comprehensive programme that addresses output and orientation simultaneously.
This classification structure directly informs training prescription and makes individual tracking meaningful over time.
Closing the Loop
Winning collisions begins with a player’s ability to accelerate their own mass — quickly, over short distances, and with effective ground mechanics. This is both a skill and an athletic quality. The ability to then accelerate an opponent’s mass requires mass-specific power that can be rapidly adjusted and skilfully applied through the ground at the moment of contact.
Traditional strength and power training remains a prerequisite. Solid strength levels demonstrate capacity and potential. But the transfer to field-based collision dominance cannot be assumed. It must be developed, trained, assessed, and iterated — with tools and methods that actually reflect the demands of the task.
The DynaSled is one of the few instruments that allows coaches to do all three: train horizontal power, test it, and use the resulting profile to teach its application in the most mechanically relevant way available outside of contact training itself.
Dean Benton
Dean Benton has spent more than two decades preparing athletes for the demands of elite contact and field sport. His career spans Rugby Australia, England Rugby, France Rugby, Japan Rugby, Argentina Rugby, Brisbane Broncos, Adelaide Crows, Melbourne Storm, Leicester Tigers and the Australian Institute of Sport. He is one of the most experienced speed and performance coaches operating at the intersection of sprint mechanics, collision preparation and injury prevention in professional sport.
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