When to Flag in Climbing and How to Do It (With Videos)

If you’ve ever reached for a hold off to the side and felt your body swing out like a door on a hinge, flagging in climbing is the fix. Knowing when to flag and how to do it turns those off balance, arm heavy moves into something calm and controlled. It’s one of the first pieces of climbing technique worth dialing in if you want to climb harder without torching your grip, and the videos below show exactly what it should look like on the wall.

My gym recently opened back up for 2-hour reservations, and that time limit got me thinking. If I want to hit my goals by the end of the year, I need to make every session count. Technique work is a big part of that, and after a long break away from climbing I could feel my flagging had gone rusty. So I dug into it, cleaned it up, and pulled together everything here so you can get back on the wall with guns blazing too.

What is a flag in climbing? Flagging is an advanced but genuinely fundamental technique in bouldering and rock climbing. A flag is when you use your free foot as a counterbalance to hold your position and stay balanced while you move your hands. The further your hand reaches out to the side, the further your trailing leg needs to reach the opposite way.

Table of Contents:

• When Do You Flag and How to Do It
• Outside Flagging
• Inside Flagging
• 3 Reasons Why Flagging is Important
• Common Mistakes In Flagging
• Evaluating Your Flagging Skills
• Drills to Help Train for Flagging

When To Flag In Bouldering and Climbing

Most of the time you’ll flag when you’re reaching for a hold that sits off to the side of your center of gravity, or when you only have one solid foothold to work with. There are two main flags, and the one you pick depends on where that foothold is. Read the position first, then choose the flag that fits.

Outside Flagging:

When to use it: Reach for an outside flag when the foothold is higher up and closer to your stable handhold, and your next handhold is out to the side of your center of gravity.

What is it: An outside flag is when you place your free foot on the outside of your leg. Your hips stay parallel to the wall the whole time, so there’s no turning involved.

Steps to do it: 

1. Before you move to the next handhold, look at the direction you need to reach and decide if it’s an outside flag or an inside flag. If it’s an outside flag, keep going to step two. If it’s an inside flag, jump down to the inside flag steps below.
2. If you’re reaching to the right, make sure your left foot is on the foothold. If you’re reaching to the left, make sure your right foot is on the foothold.
3. With the free foot, move it behind your leg and foothold while you keep your hips parallel to the wall.
4. Extend your counterbalance leg until it’s straight and set the toe against the wall.
5. While you smear that counterbalance foot, reach for the next hold.

Inside Flagging:

When to use it: Inside flags come up most when the foothold is lower down, your body is more stretched out, and your next handhold is off to the side of your center of gravity.

What is it: An inside flag is when you bring your counterbalance leg through the inside of your stable leg. To make the move, your hips turn the opposite way from where you’re reaching and both knees end up pointing the same direction.

Steps to do it:

1. Before you move to the next handhold, look at the direction you need to reach and decide if it’s an outside flag or an inside flag. If it’s an inside flag, keep going to step two. If it’s an outside flag, head back up to the outside flag steps above.
2. If you’re reaching to the right, make sure your left foot is on the foothold. If you’re reaching to the left, make sure your right foot is on the foothold.
3. With the free foot, move it in front of your leg and foothold while you turn your hips perpendicular, pointing the opposite way from where you’re moving. Your hips and knees should all face the same direction. If you’re moving right, point your hips and knees left, and the other way around if you’re moving left.
4. Extend your counterbalance leg until it’s straight and set the toe against the wall.
5. While you smear that counterbalance foot, reach for the next hold.

Why Flagging is Important

Like I said up top, flagging is one of the most fundamental techniques for leveling up your climbing. Here are the three benefits climbers notice most.

It helps increase your sideways reach

Plenty of routes ask you to reach off to the side of your center of gravity, and if you have short arms or the hold looks just out of range, a flag can buy you the extra inches you need to latch it. 

It decreases the energy needed to reach the hold

Controlling your momentum while you reach to the side takes real effort. It can burn a lot of energy to haul your body into that position and keep yourself from tipping off balance while you do it. 

Flagging cuts that cost. It balances your body and drops your center of gravity into a spot where your arms can stay straight while your legs and core, the big muscles, do the work of getting you to the hold.

Flagging prevents swinging

In a lot of the spots where flagging helps, reaching without it would tip you off balance and the swing would pull you off the wall. Flagging stops that momentum before it starts, so you don’t barn door off the move. If swinging is a regular problem for you, it’s also worth looking at how you use static versus dynamic movement.

Common Mistakes In Flagging

Like most climbing techniques, flagging comes with a handful of mistakes that almost everyone makes early on. Knowing what they are makes them a lot easier to spot and fix in your own climbing.

Flagging in the wrong direction:

A lot of newer climbers (me when I first started), know they’re supposed to move their hips or throw in a flag, but they aren’t sure which way it should go. So it’s really common early on to flag in the wrong direction.

How to recognize this mistake: The easiest tell is to check if your toe is pointing the opposite way from where your hand is reaching. If your toe and your hand point the same direction, you’re flagging the wrong way.

To avoid this mistake: If you’re reaching to the left, your flagging leg goes the opposite way. The way I keep it straight is to remember that a flag is a counterbalance, so if I reach one way, my leg reaches the other.

Using the wrong type of flag:

A lot of the time climbers throw in an outside flag when it actually makes a higher hold harder to reach. 

Other times they’ll use an inside flag when the foothold is already pretty high. Moving your leg to the inside of your stable leg when it’s up high gets awkward fast, and it often burns more energy than skipping the flag altogether.

How to recognize this mistake: A good sign is that the flag is eating up a ton of energy and feels more tiring than if you’d never flagged at all.

To avoid this mistake, look at how high the foothold is and think about what each flag would take. 

If the foothold is clearly higher, go for the outside flag. If it’s clearly lower, go for the inside flag. If you’re not sure, just do whichever flag feels easiest for you.

Not leveraging your flagging foot:

When climbers are first learning to flag, they often stick their foot out like a dog or cat’s tail for balance but never actually use it to push their weight the direction they want to go.

How to recognize this mistake: Easiest way to catch it is to look at your foot and see if it’s pushing against the wall. If it’s off the wall or just floating out to the side, you’re making this mistake. Cleaning this up ties straight into your footwork.

To avoid this mistake: When you use your flagging foot as a counterbalance, smear it against the wall too so you can push off it like a real foothold.

Not keeping your hips as close to the wall as possible

When climbers are just learning to flag, they’ll often do the leg movement fine but leave their hips, and their whole center of gravity, hanging out away from the wall. That forces you to pull with your arms instead of leaning on your legs for support.

How to recognize this mistake: Notice how much arm power you’re using to drag your body into the wall when you make a move. If it’s a lot, your hips are probably too far out.

To avoid this mistake: Once your feet are set in flagging position and before you move your hands, check how far your body is off the wall and pull it in as close as you can.

Evaluating Your Flagging Skills

Taking a look at your flagging is worth it when you’re trying to improve or when you want to check whether you’re doing it correctly and efficiently.

When to evaluate your flagging technique: If you’re brand new to flagging, an evaluation probably won’t tell you much yet. But if you’ve been practicing it or you’ve tried flagging on routes and still don’t feel confident, that’s a good time to take a closer look.

Evaluating your flagging while you run drills is usually the easiest way to do it. If you’d rather check yourself on routes while you climb, you can use the same questions.

Outside Flag Evaluation How-To

Outside flagging is the most common flag and the easiest, but getting a read on where your outside flag stands right now helps your training. Here’s what to look at.

• Hip angles and placement:
  • Did your hips stay parallel with the wall through the whole movement?
  • Were your hips close to the wall the whole time?
  • If your hips drifted off the wall, did you correct it by pulling them back in?
• Leg movement:
  • Did you move your leg in the right direction, behind the leg on the foothold?
  • Did it take a long time to get your leg into the right position?
  • Did you move your feet before moving your hands?
  • Was your leg stretched out straight before you moved your hands?
  • Did the leg movement feel comfortable?

Inside Flags Evaluation How-To

Since inside flags and outside flags are different movements, you evaluate them a little differently. Here’s what to review for inside flagging.

• The quality of your turns:
  • Did you turn your hips the correct direction?
  • When you turned your hips, how easily did they turn and did it feel comfortable?
• The speed of your turns:
  • Did it take a long time to work out which way you needed to turn? 
  • Did it take a long time to actually turn your hips?
• How close you can bring your center to the base:
  • Did you keep your hips close to the wall?
  • Did you pull your hips back in when you noticed them drifting off the wall?
  • Were you able to keep your hips close to the wall through the entire movement?

Drills to Help Train for Flagging

Line and Flag

This is a great drill for getting a feel for which direction to flag on each move.

Focus: Use this drill to practice inside flagging and back flagging.

What you need: Space on a gym wall where you can traverse.

What you do:

1. Reach for a new hold.
2. Picture the line running straight down from your hand to the ground.
3. Turn and step on a foothold that sits in line with your hand and the ground.
4. Flag your other foot and move your body to center on that line.
5. Reach for the next hold.

Flagging Routes

This drill is great for making flagging feel automatic so it shows up on its own while you climb. It’s also a solid one to run at the start of a session so flagging stays on your mind through the rest of your training. For more ideas like this, our bouldering drills guide is a good place to keep going.

Focus: Use this drill to practice inside flagging and back flagging.

What you need: Two or three routes that are 2 to 3 grades below your level.

What you do: 

1. Climb each route and make yourself flag on every move, even when it doesn’t seem necessary.
2. Take a break and repeat step one 2 to 3 times.

Want a new drill to work on every week? The free Send Edition newsletter drops one short climbing drill in your inbox every week, about 15 minutes each, so moves like flagging keep improving between sessions. Grab it here and level up your climbing with 15 minutes of training.

Frequently asked questions

What is flagging in climbing?

Flagging is when you use your free foot as a counterbalance to hold your position and stay balanced while you move your hands. The further your hand reaches to the side, the further your trailing leg reaches the opposite way to keep you steady.

When should you flag in climbing?

You flag when you’re reaching for a hold that sits off to the side of your center of gravity, or when you only have one solid foothold. It keeps you from swinging off balance so you can reach the hold with your legs and core instead of pulling hard with your arms.

What’s the difference between an inside flag and an outside flag?

On an outside flag you put your free foot on the outside of your leg and your hips stay parallel to the wall, which works best when the foothold is higher up. On an inside flag you bring your free leg through the inside of your stable leg and turn your hips the opposite way from your reach, which works best when the foothold is lower down.

Why does flagging save energy?

Flagging drops your center of gravity into a balanced spot so your arms can stay straight while your legs and core do the work. That means less pulling, less swinging to fight, and less grip strength burned on each sideways reach.

What’s the most common flagging mistake?

Flagging in the wrong direction is the big one. A quick check is your toe: it should point the opposite way from the hand that’s reaching. If your toe and reaching hand point the same direction, you’re flagging the wrong way.

Sara Climbing Coach, Climbing Trainer, Writer

Sara is the founder of Send Edition, author of '77 Drills to Help You Climb Better,' the creator of 'Elevate Your Climbing: Training Planner and Tracker,' and climbing coach.

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