THE WEIGHT OF THE JOB: LOAD CARRIAGE TRAINING FOR FIRST RESPONDERS

Load carriage isn’t optional – it’s unavoidable.

One of the most unique elements of first responder fitness compared to sport or general population is load carriage training. In what is a largely unpredictable occupation, load carriage is one of the few tasks that first responders can be guaranteed to complete almost every shift.

Police officers are spending up to 12 hours a day wearing protective vests and duty belts, firefighters have significant added weight from PPE, helmets and SCBA, and paramedics are constantly lugging first aid kits and trauma bags in and out of the ambulance.

The duration and repetition of these load carriage tasks make them high injury risks, but these risks can be mitigated with appropriate training. Load carriage has become a popular training methodology in its own right by the way of weighted vests and rucking (walking or hiking with a weighted backpack), however there are more considerations to be made for safe and effective load carriage training than just lifting and carrying heavy things.  

Load Carriage Injury Risks for First Responders

The primary consequence of prolonged load carriage is increased force applied to the body.

Compressive forces are applied top-down to bones and other tissues such as discs in the spine, or cartilage in the knees and hips. Compressive forces are always present thanks to gravity, and one of the primary roles of our cartilaginous tissues is to act as a shock absorber for this type of force but operating under load and/or at high intensity for prolonged periods can overload these tissues and lead to significant injury.

When the average person runs, the force applied to the knees and feet each time the foot strikes the ground can be as high as x11 bodyweight. With every 0.5km/hr increase in speed, the equivalent of 10kg additional load is applied to the body, and the same goes for every 1% increase in gradient. Adding weight in the form of body armour, packs, and PPE can quite easily add another 20-40kg of load which has to be absorbed by joints and bones during activity.   

Over time, this can cause tissues to break down leading to tears. It may occur suddenly, or it may occur so slowly that you don’t notice the damage until it’s too late. Around 50-60% of load carriage-related injuries occur to the lower limbs, while 22-26% are related to the back and spine.

Injuries to the back are one of the most common in front line emergency service workers, in part because it’s particularly vulnerable to load carriage because of the way the spine bends. Discs are cartilaginous connective tissues that link our vertebrae, and when amplified compressive force is applied to the spine during flexion or extension, it creates a shearing force that can cause discs to bulge which may develop into a herniation.

How Equipment Placement Increases Energy Cost

Another factor alongside injury risk that first responders must consider is the increased energy cost of load carriage. This is particularly prevalent for firefighters who are tasked with carrying the most additional weight of all the emergency services in the form of PPE and SCBAs and undertake high intensity activities.

Load applied to the waist is the most efficient location with regards to energy cost, while the thigh and feet are the least efficient. This is relevant for police officers who split their equipment across a protective vest, duty belt, and potentially thigh holsters, and the decision of what goes where could be more costly than you think. For example, as little as 500g applied to the thigh increases energy output for any given task by 3.5%.

Similarly, the placement of additional weight within a backpack influences energy cost, as well as balance; the vertical placement of additional load can negatively impact balance, while the horizontal placement can negatively impact energy cost.

A weight stored high in the pack but close to the body will have a lower energy cost, but will decrease balance, while a lower weight stored away from the body will improve balance but increase energy cost. Additionally, load carriage decreases mobility which adds to the overall risks of slips, trips and falls.

To avoid slips, trips and falls (one of the leading causes of injury among first responders), additional weight carried in a backpack should be low and close to the body for optimal energy cost and balance.

How to Train for Operational Load Carriage

When beginning load carriage training, consider the following guidelines according to the F.I.T.T principle: 

Frequency: Every 10-14 days

Intensity: Below but building up to operational weight, at operational speed, on familiar and predictable terrain.

Time: Up to but not exceeding the duration of occupational load carriage tasks.

Type: Load placed on the torso or hips.

For those with more load carriage experience:

Frequency: Every 7-10 days

Intensity: At or above operational weight and speed, on terrain that best mimics the requirements of the job

Time: High load for shorter duration, or operational load for longer duration.

Type: Load placement that best mimics the requirements of the job.

To maximise the training effect, load carriage training sessions should complement aerobic conditioning and regular strength training in a variety of rep ranges (as low as 3 sets x 4 reps). Target areas should include the glutes, quads, hamstrings, calves, upper back, forearms and core.

The following is a sample strength training session for the purpose of load carriage:

A.    Trap Bar Deadlift 3 x 4

B.    Hip Thrust 3 x 8

C.    Zercher Step Ups 3 x 8 each  

D.    Dumbbell Seal Rows 3 x 10

E.     Leg Press Calf Raise 3 x 15

The goal of aerobic conditioning for load carriage should surround building a strong baseline and high top-end capacity. This involves both high intensity, short duration efforts (HIIT sessions around RPE 9), as well as low intensity, long duration efforts (commonly referred to as Zone 2 training). Where possible, aerobic conditioning sessions should be off-feet to avoid the same high-impacts placed on the body during load carriage sessions, thereby helping to avoid overuse injuries.

Load Carriage for Female First Responders

It is important to mention that the demands of load carriage for women are not necessarily the same as men. The obvious reasons for this fact are due to generalisations around body size and muscle mass and how that influences the relative load applied from the additional equipment.

While it is not true for all female first responders, it is generally accepted that the average female is lighter, smaller, and has lower absolute muscle mass than the average male. When this is the case, the energy expenditure and injury risk are significantly higher.

Additionally, the fit of body armour is traditionally designed to suit the male body, and worn load carriage such as PPE, full body suits, body armour, and duty belts, are often mis-fitted to females due to the larger variability in sizing compared to males. Females are more likely to fall in between sizes or require custom sizes and are instead assigned the closest available size.

Finally, much of the load carriage research until recent years was completed with male subjects, so many of the findings, recommendations, and training methods may not be appropriate for the female first responder.

A combination of these factors makes female first responders more prevalent to load carriage injuries than male colleagues. Properly fitted equipment and appropriate load distribution should be combined with a solid strength and conditioning program that includes load carriage to avoid these risk factors.

Summary

Load carriage is an unavoidable and high‑risk demand across all emergency service roles, requiring careful consideration beyond simply carrying heavier loads. Prolonged and repetitive exposure increases injury risk, particularly to the lower limbs and spine, while also significantly increasing energy cost and reducing mobility. These risks can be effectively managed through intelligent equipment placement, appropriate load distribution, and structured training guided by occupational demands.

A balanced approach that integrates progressive load carriage training with strength and aerobic conditioning is essential. Special consideration must also be given to female first responders to reduce inequitable injury risk. When applied correctly, load carriage preparation enhances performance, resilience, and long‑term career longevity.