How to Flag – Climbing Technique 101

The Flag is a crucial technique in climbing that can greatly improve a climber’s balance, efficiency, and overall performance. It involves extending one leg out to the side to maintain balance and control while climbing. Whether you’re a beginner or an experienced climber, mastering the Flag can help you tackle more challenging routes and reach new heights.

The Flag is by far my favorite climbing move, even when good footholds are available, my preferred style of climbing involves the Outside Flag in conjunction with the Back Step as opposed to having both feet on footholds.

📚 This article is part of a wider guide: Climbing Technique 101

What is the flag and why use it?

The Flag is a climbing move in which a climber uses one of their legs to maintain balance while reaching for the next hold. Only one foothold is used in this move and the other leg is extended, creating a flag shape. This extended leg, or flag, allows climbers to shift their center of gravity and find stability on the rock.

Flagging can be used when only one foothold is available, but in many cases, it should also be used even when two footholds are available. Two footholds are likely to put the climber in an awkward, sometimes crunched position and may lead to a loss of balance. With a flag, however, the climber is always in balance.

This fundamental climbing move forms the basis of many more advanced techniques. By having the ability to maintain balance on just one leg, climbers can unlock more freedom of movement. Furthermore, being skilled in the flag can greatly improve a climber’s overall efficiency and technique. Allowing them to climb better and preserve energy on long routes!

how to perform the Outside Flag

The Outside flag is the most common, and easiest type of flag. This type of flag only has one rule: opposite hand and foot.

What this entails is that the hand you are reaching with should be on the opposite side of the leg you are currently flagging. For example, if you are reaching for a hold on the left side, you should be flagging with your right foot. And vice versa.

The outside flag can be performed from a hip-in position as well as a hip-square position.

Other types of Flags

While flagging mostly refers to the most commonly used “Outside Flag” there are two more types of flags that exist. Let’s take a closer look at those.

Back flag

The Back Flag is a less common type of flag that is used to prevent a barn door while using a hand and foothold on the same side. Without a Back Flag, your body would open up like a door, and this results in a loss of balance.

The barndoor occurs because your center of gravity falls outside of your base of support. This can be prevented by swinging the leg closer to our base of support, resulting in a back flag.

The back flag has two rules: same side hand and foot and hip square position.

inside flag

The Inside Flag is the least common type of flag. During this move, your hip is twisted in and your leg is flagging on the inside of your body, hence the name “Inside Flag”. Just like with the Back Flag, this technique requires you to be on the same side hand and foot.

Applications for this type of movement are extremely rare and you might not need it for a while but it is good to know it exists.

common mistakes while flagging

1. Reaching on the flagging side: a common mistake among novice climbers is to reach on the same side they are Outside Flagging. This is extremely hard to pull off and defeats the purpose of making a flag efficient! Always reach on the opposite side of your Outside Flag.
2. Not releasing the flag: some climbers will forget about their flagged leg once they reach the next hold, resulting in a repeat of mistake #1.
3. Only flagging on one side: beginner climbers tend to favor one side of their hands and legs. Usually, this is your dominant side. Once climbers learn the flag, they may only use it on one side. But you can flag on the other side as well, and gain the same benefit, I promise you!
4. Not smearing the flagged foot: a flag should not only be used as a means to gain balance, but you can also gain leverage from your flagged foot! Keep it close to the wall, and smear from that foot whenever possible. You can gain a lot of extra power by using your flagged foot as an extra foothold instead of just using it for balance purposes.

practicing the flag

The Flag is one of those moves that should be practiced in every session if you haven’t unlocked the muscle memory just yet (once you do, you will be flagging all the time, trust me).

I’d also recommend learning to Back Step first before learning the flag. This move forces you to throw your weight at your feet (as opposed to your hands) which is essential for making a flag work. Additionally, the Back Step and flag form a powerful combination!

When practicing the flag, focus on the Outside Flag first. This is the easiest, most common, and most useful type of flag. Practice at an Indoor Bouldering Gym on easy problems that are way below your climbing grade.

During this practice, you should force yourself to make every move with an Outside Flag. Remember opposite hand and foot! Always reach the other side you are flagging. And release your flag every time.

Once you have the hang of the Outside Flag, combine it with a Back Step. You’ll have to use a Foot Swap or step-through to make a sequence out of these moves.

It takes some practice but once you got these techniques down, you’ll be an efficient climbing machine!

when the flag in climbing

Flagging is one of those moves that should be used all the time in climbing. If you don’t remember flagging during your last session, you definitely didn’t climb very efficiently! Here are some use cases for The Flagging technique:

1. Regaining balance: the most common use for flagging is to shift your center of gravity to a more favorable position through an extended leg. So you should always consider the flag when you feel your balance is off. One foothold is oftentimes better than two footholds!
2. Reaching for difficult holds: especially when a flag is combined with a Twist Lock, the flag can allow you to reach a hold you could otherwise not reach.
3. Resting: flagging offers a great way to take the pressure off the arms and push it towards the legs. You can use a flag to create a resting position and rest your arms on a route.

There are so many use cases for the flag I definitely forgot to sum some up here but this is just what came off the top of my head.