Fitatmidlife’s Rucking Glossary – Learn About Rucking

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FitAtMidlife’s Rucking Glossary

Rucking is walking with a loaded backpack – and not just in the woods! “Ruck”, short for “rucksack”, is military slang for a backpack. This is a cheap, simple exercise that burns calories and builds aerobic endurance due to the added weight.

Rucking - with origins in the military , it has found a new place in the fitness landscape

As a beginner in rucking you’re going to run into some terms and acronyms you may not be familiar with. But we’re here to help.

Here’s a rundown on some of the common terms and lingo that are utilized by the GORUCK organization as well as the wider rucking community.

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Have a read through and increase your rucking knowledge. Did we miss an item? Reply in the comments – preferably with a source, if possible.

100 MPH Tape

100 MPH Tape is what duct tape is called in the military. Why? Legends say it was purported that it could be used to hold a jeep together traveling at 100 mph. In rucking, it’s commonly used to repair gear, or to hold stuff where it should be for the duration of a ruck.

1000D – 1000 Denier

1000D refers to 1000 Denier Cordura – the material used in the GORUCK GR1 backpack, and others. Denier refers to the linear mass density of the fibers used in the materials. 1000D offers exceptional strength, abrasion resistance, and other benefits. Other rucksacks may be made from less robust 500D Cordura (which is lighter).


The ALICE Pack is the standard US Army load bearing gear that was in extensive use in the 70s and 80s. ALICE stands for All-Purpose Lightweight Individual Carrying Equipment. It’s been largely replaced by the newer MOLLE pack, but can still be found in use by some units, and in surplus stores.

AAR – After Action Review

An AAR (After Action Review) is a debriefing – a chance to reflect on what went right, what went wrong, and how to do it better in the future. It’s a chance to share knowledge, and mentor others – it’s essential to the team building process. An AAR is common-place after a GORUCK challenge. As with many practices of the rucking community, it’s inspired by military AARs.

ACRT – Advanced Cellular Repair Technology (aka Beer)

ACRT short for Advanced Cellular Repair Technology is often used to refer to a celebratory cold beer you might have after completing a challenge.

AFAP – As Fast As Possible

AFAP means As Fast As Possible – as in Ruck 3 miles AFAP.

APFT – Army Physical Fitness Test

The APFT is the Army Physical Fitness Test. The test is designed to test the muscular strength, endurance, and cardio fitness of soldiers. It consists of three events: push-up, sit-up and a two-mile run, with each being scored on a 0 to 100 point scale. What does this have to do with rucking? Not much in particular – but with many of the ruck community being active or ex-military you’ll likely hear it at some point.

AR 670-1 Army Regulation

AR 670-1 is the US Army Regulation for Wear and Appearance of Army Uniforms and Insignia. It terms of rucking, it defines what sort of non-military gear can be used, and how it must appear. You will hear mention of “AR 670-1 compliant” – meaning gear or apparel meets the requirements of this regulation. In a nutshell, to use a civilian backpack – it can’t have logos, can’t be see-through, and must match the camo pattern of the uniform worn – or must be all black in color. Here’s the complete regulation AR-670-1 straight from the source.


A cadre is defined as a small group of people specially trained for a particular purpose or profession. In rucking, this typically refers to the Special Forces cadre that is the core leadership of GORUCK challenges and events.

Charlie Mike – Continue Mission

Charlie Mike means Continue Mission.


Cordura is the brand name for a collection of fabrics used in a wide array of products including backpacks, trousers, military gear and performance apparel. Cordura fabrics are known for their durability and resistance to abrasions, tears and scuffs. The GR1 backpack, and other backpacks made by GORUCK, are constructed of 1000D Cordura.

EDC – Every Day Carry

EDC is short for Every Day Carry used to describe gear (such as backpacks) that you can use in every day life. There’s no firm definition of what comprises EDC, but in general it is used to describe practical items you might use for personal or business commute or travel – as well as during a ruck challenge.

FLR – Front Leaning Rest (aka a Plank)

An FLR or Front Leaning Rest is a plank – an isometric core and stability exercise that is agonizing when done for time.

GRC – GORUCK Challenge

GRC is short for GORUCK Challenge. The challenges are the primary team activity that GORUCK events are based on. There are 3 levels (Light, Tough, and Heavy), as well as HTL events (which require all 3 challenges!), and other special events.


The GORUCK Heavy requires carrying a loaded ruck 40 miles over 24 hours (or more). It’s not easy – the average completion rate is only 50% – meaning about half the people who start do not finish. Like the “Tough”, persons under 150 lbs must carry 20 lbs, people over 150 lbs must carry 30 lbs. Compare to the Tough and Light challenges.


The GORUCK Light is the introductory challenge level. It requires carrying a loaded ruck 7-10 miles of distance, in a time span of 4-5 hours. Persons under 150 lbs must carry 10 lbs, people over 150 lbs must carry 20 lbs. The average completion rate for this event is 100% – which means it’s a great place to start. Compare to the Tough and Heavy challenges.


A GORUCK Tough is the intermediate challenge level. It requires carrying a loaded ruck 15-20 miles over 10-12 hours. The average completion rate is 94% – meaning nearly everyone that starts it will finish. Persons under 150 lbs must carry 20 lbs, people over 150 lbs must carry 30 lbs. Compare to the Heavy and Light challenges.

GRPFT – GORUCK Physical Fitness Test

The GRPFT is the GORUCK Physical Fitness Test. It consists of 2 minutes of Push-Ups, 2 minutes of Sit-Ups, a 3 Mile Run, and a 5 Mile Ruck.

GORUCK GR1 21L - in Multicam color.  This model was formerly known as the GR0


The GR0 is not an official GORUCK backpack model – any longer at least – it’s now known as the GR1 21L – the smallest GR1 size.

GORUCK GR1 21L in Steel

GR1 – GORUCK’s original rucksack design

The GR1 is GORUCK’s original rucksack design – versatile, tough, and made especially for the ruck – but super-practical for EDC also. Available in two sizes (21L and 26L), it’s a great piece of gear. It’s also very popular with the rucking community – so you’ll see this acronym a lot. It’s often used as “I have a GR1 21L” or “I have a GR1 26L”. GORUCK also offers the GR2, GR3, as well as other gear.

GORUCK GR2 in Black Multicam


The GR2 is GORUCK’s larger size ruck – bigger than the GR1, it’s made for world travel.

GORUCK GR3 with MOLLE front panel option


The GR3 is GORUCK’s ruck that is meant to be the largest possible carry-on size. It’s got one large main compartment so it’s great for larger items like boots and camping gear.

GRHQ – GORUCK Headquarters

GRHQ stands for GORUCK headquarters. It refers to the HQ staff of the GORUCK organization.

GRT – Short for the “GORUCK Tough” community

The GORUCK Tough (GRT) community are those individuals who have completed a GORUCK Challenge : Light, Tough, or Heavy. There is a Facebook page that is a closed group.

You may see the GORUCK Tough Patch on the rucks of these individuals. This patch is not for sale. It takes inspiration from the First Special Service Force’s spearhead, and the only way to earn it is to pass the GORUCK Challenge.

EMOM = Every Minute On the Minute

EMOM, or Every Minute On the Minute, is a workout instruction that requires you to repeat some task every minute on the minute, for some number of minutes. We’ve written extensively about EMOM.


GORUCK ruck sacks don’t have drainage holes. Some people add their own grommets to help the bag drain quickly if it is immersed.

Hip Belt or Waist Strap

A Hip Belt or Waist Strap is a feature of a rucksack that helps you put more of the load onto your hips and legs – as opposed to the back. This can be an essential part of longer rucks – it gives you the ability to adjust the load to stave off fatigue as well as to utilize the larger leg and hip muscles to do more of the work.

HTL – Heavy+Tough+Light

An HTL event is one that requires a Heavy (40 miles, 24 hours+) followed by a Tough (20 miles, 10-12 hours) and finally a Light (10 miles, 4-5 hours) – with nothing but a “brief break” in between each. It’s considered the ultimate achievement in rucking.

Jerry can or Jerrycan

A jerry can or jerrycan is a large container for carrying liquids – typically gasoline or water. There’s a good chance you’ll become acquainted with carrying one (or a log) at a GORUCK challenge.

MOLLE Webbing on a GORUCK GR1 backpack

MOLLE -MOdular Lightweight Load-carrying Equipment

MOLLE stands for MOdular Lightweight Load-carrying Equipment. MOLLE webbing is rows of heavy-duty nylon stitched onto a vest or backpack to allow for attachments and versatility. It’s a popular feature on rucksacks and other military gear. The picture to the right shows MOLLE webbing.


Paracord is parachute cord. It’s a lightweight nylon rope originally used in the suspension lines of parachute – so it’s tough. But it’s also versatile. It is for many other tasks and is used as a general purpose utility cord by both the military and civilians

The GORUCK USA Patch - fits perfect on the velcro patch area of the GORUCK GR1 rucksack


Patches play a big role in rucking – and they serve multiple purposes. First, a good rucking backpack has a velcro area for patches. Completing events typically will earn a patch. But there are patches for other purposes as well, such as morale patches.

What’s proper patch display protocol? It’s pretty loose – it’s your chance to show off your past accomplishments, send a message to your team mates, or to display some style and personality.

Having said that – just don’t show off something you didn’t earn (like a Tough patch, etc.).

PT – Physical Training

PT is Physical Training – aka “working out” in the civilian world.

GORUCK Pre-selection

Pre-selection is 8 hours of GORUCK Selection, a rucking-based endurance event with a less than 2% pass rate inspired by Special Forces Assessment and Selection. Pre-Selection tests your individual readiness to meet the standard at GORUCK Selection.

Radio Ruck

The Radio Ruck is a GORUCK product. It’s a rucksack the same capacity (21 liters) as a GR1, but in a shorter height (so it’s got more depth and width). The Radio Ruck is availably occasionally in limited quantities, and is not an item stocked by GORUCK year-round. Why is it called the Radio Ruck? Because it was made to accommodate a PSC-5 military radio and spare batteries – a piece of hardware in frequent use by US Army Special Forces.

Ruck (as a noun)

Ruck is both a verb (i.e. to “ruck”) and a noun. Your ruck is your rucksack, backpack, or just plain ruck. Rücken is an old German word for back, and a sack is a sack – so bag or sack that goes on your back.

Ruck (as a verb)

Ruck is both a verb (i.e. to “ruck”) and a noun. To ruck means to go on a ruck – a walk or march with a loaded rucksack.

GORUCK 20 lb ruck plate and a GORUCK Echo ruck plate

Ruck Plates

Ruck Plates are specially designed weight plates available in 10 lb, 20 lb, 30 lb, and 45 lb sizes. They are designed specifically for rucking, but also incorporate easy to grip handles so they can be used for resistance training outside of the rucksack as well. They make rucking more efficient, pleasant, and are recommended for serious ruck trainees – and you can read more about the benefits of ruck plates.

Further, the GORUCK ruck plates come in two models: Standard and Expert. The Expert models are more compact, and work better with certain rucksack designs. Many people choose based on comfort.

Ruck Swings

A Ruck Swing is a kettlebell swing type of movement using your fully loaded rucksack. Grab your bag by the top handle and swing it. Done right it’s a hip-hinge movement. You might be required to do these as part of a GORUCK challenge.


GORUCK Rucker 2.0 - a purpose built rucksack - no laptop compartment, more padding in the straps , and compatible with GORUCK Expert ruck plates.

The Rucker 2.0 is a GORUCK backpack model. It’s purpose built for ruck use and less so for EDC. Compared to the GR1 the main differences are: No laptop compartment, thicker straps, plate carrier in the main compartment. It works best with the GORUCK Expert plates. The plates will stay nice and high on your back – as they should be. Otherwise it’s the same size, made from 1000D cordura, and has a frame sheet.

35L Sea to Summit

Sea to Summit is a manufacturer of many hiking and mountaineering items – including waterproof bags that are popular for ruck events that guarantee water immersion.

Sternum (or chest) strap

A Sternum Strap or Chest Strap is a feature of a rucksack that helps you keep the load in the proper place. By fastening across the chest it keeps the load where you need it to be, but also gives you the ability to adjust the load to stave off fatigue – which can be important on a longer ruck. Removable sternum straps attach via clasps to the MOLLE webbing on the shoulder straps of a ruck for stabilization - in coyote brown color.

Why GORUCK Products? We’re a GORUCK affiliate – so if you order equipment after clicking the links in this article we receive monetary compensation. But that’s not why we recommend GORUCK. It’s because their equipment is innovative, built to last, and made in America. They are the driving force behind rucking not just as exercise, but as a way to make people better. And that’s why we love them.

Photo Credits

  • Some product photos on this page are provided by, and property of GORUCK.
  • Some photos on this page are provided by the equipment manufacturer.