Antagonist Training Climbing | 20 Best Exercises | Adjunct Compensatory

Antagonist Training Climbing Best Exercises Adjunct Compensatory Training

Antagonist Training? Many climbers solely focus on finger-, pulling-, and core muscle strength. Often the corresponding antagonist muscles are neglected and dismissed as unimportant. 

The consequences
Injuries, postural defects and stagnation.

In the following, the 20 most important climbing related antagonist exercises are described in detail. 

Compensatory/antagonist training for climbers 

We will counteract the usual pulling movements during climbing with a targeted antagonist and stabilisation training.

All exercises are mostly aimed at strength endurance (many repetitions, relatively low weight) because the aim is not to build up muscle mass but to prevent or compensate for potential imbalances. 

Risk through one-sided training.

  • Climber’s Huchback
  • Muscular imbalances
  • Increased susceptibility to injury 
  • Stagnation of performance

20 antagonist exercises for all climbers

Compensatory training for the forearms

The forearms (flexor muscles) are extremely stressed when climbing. The forearm muscles are very complex and consist of many individual muscle strands.

In order to make full use of the strength of the forearms and to maintain the balance between flexors and extensors, serious compensatory training is necessary. 

With Antagonist training of the forearms, we benefit in two ways.
Firstly, the performance of the forearm flexors (intramuscular coordination) increases, and secondly, we prevent injuries.  

1. Hyperextending

 Antagonist Training climbing forearm
Hyperextending – starting position
 Antagonist Training climbing
End position

A dumbbell or resistance (thera-) band is used to strengthen the finger extensors. 

Execution of movement:
Put your forearm on your knee or thigh to stabilize it. Start the exercise from a neutral position (wrist straight) and stretch your wrist upwards. End the exercise back in the neutral position. 
– 10-15 repetitions. 3 sets

Isometric variation: Hold in the hyperextended position (1 min).

2. Pinch Grip

Exceptionally good adjunct compensatory exercise for climbers. It also strengthens the extensor and thumb flexor muscles of the forearms (with extended wrist!!) and imitates a pinch grip. 

Bouldering antagonist training
Pinch Grip – Ingenious exercise!

Standing upright, hold the weight in the pinch grip. The width of the weight used can be varied. 
In the beginning, it is recommended to work with lighter weights and to train your endurance (30 sec. holding time). 
Later in the direction of maximum force (10 sec.).

If you do not have weights at your disposal, you should still attempt this exercise – just be a little inventive. Basically, anything heavy and wide enough to be held in the pinch grip works. This can be a stone, chair, ski, tools, or anything else. 

3. Internal rotation

Antagonist Training bouldering
Internal rotation – starting position
Antagonist Training bouldering
And back to the starting position

Climbing mainly trains the external rotation. 
With this exercise, the antagonist muscle is strengthened. There are special machines to train these muscles, but a simple hammer or resistance band also does the job. 

Execution of movement:
Sit upright, rest your forearm on your thigh and execute the movement slowly and in a controlled manner. 
– 20 repetitions

4. Resistance band/power fingers

Antagonist Training climbing forearm
Antagonist Training climbing forearm

A good warm-up exercise that simultaneously trains all finger extensor muscles

Execution of movement:
Put the TheraBand (I recommend the blue Theraband) around your palm and straighten your fingers slowly and in a controlled manner. 
– 20-25 repetitions

3 useful training devices for forearm muscles:

Chinese Balls*

Antagonist Training for climbers – Shoulders and Back

The shoulders and back I have summarised in one chapter, as many exercises require both areas and usually involve a combination of both muscle groups. 

Injuries or overloading of the shoulder area occur quite often when climbing and bouldering.  

Climber’s Hunchback

A muscular imbalance in the back and shoulders can lead to a “hunchback”, which is quite common among climbers. It can also increase the risk of shoulder injuries and lead to further postural damage (spine, intervertebral discs).

In addition, the radius of movement of the shoulder joint is usually reduced. This is something we want to avoid at all costs, and there are some very good exercises for this. 

1. T-Y exercises

These 2 exercises use those parts of the back muscles that are responsible for rotating, stabilising, and moving the shoulder blades.

They counteract the usual climbing stresses and ensure a balanced relationship between the shoulder and back muscles. These two antagonist exercises should be practiced regularly by every climber

Adjunct Compensatory Training climbing

T – Exercise

The exercises can be done standing up and you can use a TRX trainer, rings, or a rope. 

Adjunct Compensatory Training climbing back
Starting position
Adjunct Compensatory Training climbing back
End position

Starting position:
Grasp rings or TRX with outstretched arms in front of your body and your palms pointing inwards. Tense your core, buttocks and legs and lean backwards (the further your feet move forward the harder the exercise will be).

Execution of the movement:
Pull both arms evenly and slowly apart until they are positioned away from the sides of the body and are in a desired T-position.

In the final position (standing upright) bring the shoulder blades together as far as possible. Slowly return to the starting position.

Maintain body tension and stretched arms throughout the exercise. If the correct execution of the exercise is no longer possible, please take a break. 
– 10-15 repetitions
– 2-3 sets

Y- Exercise

Antagonist Training Bouldering climbing
Starting position
Antagonist Training Bouldering climbing
End position

Same starting position as for the T-exercise.
Arms are moved upwards and outwards in a Y-shape. In the final position, try to pull the shoulder blades down as far as possible. 

Lying variation: 

Bouldering Adjunct Compensatory Training
Starting position
Bouldering Adjunct Compensatory Training
End position

Starting position:
Lying on the stomach (bench) with your arms sideways down on the floor… 

Execution of movement:
Tense your core, buttocks and legs and raise outstretched arms to up to shoulder height. Hold the position and release slowly. This exercise can be intensified with weights (dumbbells). 

2. Scapular pull-ups

This antagonist exercise is simple and effective and therefore one of my absolute favourites. The shoulder blade climbing exercise is an isolation exercise that aims to stabilise the shoulder blades and rotation cuff.

It keeps your shoulder blades in position and protects you from injuries during dynamic pulls. It will also have a direct positive effect on your climbing performance since almost every pulling movement starts with this movement or stabilises it.  

 Climbing antagonist training pull up
Starting position
 Climbing antagonist training pull up
Shoulder blades approaching

Starting position:
Hanging on the pull-up bar (let shoulders sag) with palms slightly more than shoulder width apart and facing forward.

In order to correctly execute the exercise, I recommend you reduce your weight by keeping your legs on the ground and using them for support. 

Execution: From a hanging position lift the body by bringing the shoulder blades down and clenching them together. Since the movement comes only from the shoulder blades the range of movement is only a few centimetres.

The arms are not bent. All the energy of the movement comes from the shoulder blades. The upper body tilts back slightly and the chest rises towards the bar.

The end of the movement is reached when the body can only be brought further up by bending the arms. It might help if you imagine that you want to bend the pull-up bar.  

Add this exercise to your warm-up program and strengthen your back, shoulders and shoulder blades without additional effort. 

You can find a practical pull-up bar for training at home for $ 50 on Amazon.
This tool helps you can keep yourself in shape for climbing and also keep on track with your antagonist training.

Easy to install – Pull up bar*

3. Shoulder blade Push up

This simple exercise trains the “serratus anterior muscle” which stabilises the shoulder blades and raises the arms to shoulder height. 

Adjunct Compensatory Training climbing push up
Adjunct Compensatory Training climbing push up

Starting position:
Classic push-up or forearm position. Arms slightly more than shoulder width.

Execution of movement: Tense core, legs and buttocks. Lower chest (let shoulders sag) to bring shoulder blades closer together.

Arms and elbows remain extended throughout the exercise. From this position, push up again. The range of motion is only a few centimetres. 
– 20 repetitions
– 2 sets

3. Rowing for climbers

Rowing prevents climber’s Hunchback and strengthens the antagonists muscles, especially the trapezius and the rhombic muscles. This exercise can be performed on a rowing machine, a pull-up bar or with TRX or rings. 

Rowing with sling trainer (TRX, rings)

Adjunct Compensatory Training Bouldering
Starting position
Adjunct Compensatory Training Bouldering
End position

Starting position:
Hold the handles of the sling trainer or the rings in your hands (arms stretched out), lean back with your body almost adjacent to the floor. The further back you lean (the higher the incline), the harder the exercise becomes. 

Movement execution:
Build up body tension in buttocks, legs and core and pull the handles towards the chest with both arms. Do not spread the elbows but keep them close to the body. To increase the training stimulus, you can block in this position for 1-3 seconds. Afterwards, slowly manoeuvre yourself back to the starting position. 
– 20 repetitions
– 2 sets

The Rings – a perfect training tool for climbing & bouldering.
– Ideal for balancing training
– Cheap (Amazon)
– Easy to attach
– Full body training
– Power and stability

Gym-Rings* – Ideal for antagonist training

Rowing on the pull-up bar:

The rowing pull-up requires the muscles in the inner back. These are mainly the trapezius and the posterior deltas. Since these muscles are responsible for the external rotation of the shoulders, strengthening these muscles helps to prevent climber’s back.

In addition, the abdominal muscles are also trained for stabilisation.

Antagonist Training climbing
Starting position
Antagonist Training climbing
Puuuuuuuull …

Starting position:
Arms stretched and at shoulder width, legs stretched and pointing directly upwards, back straight and horizontal. Shins as close as possible to the bar. The palms should be facing away from the body. 

Execution of movement:
Use your arms to pull your lower stomach as close as you can to the bar. Using your back, actively pull the shoulder blades together. Make sure you perform the exercise correctly. 
– 5-10 repetitions
– 2 sets
– 2 min. break

4. Shoulder rotation

The rotators are only strained on one side when climbing. To counteract injuries and stabilise the shoulder, balancing exercises with additional weights or a Theraband are helpful. The exercises with the Theraband are also perfect for warming up.

a.) Internal rotation

Antagonist Training climbing shoulder
Antagonist Training climbing shoulder

Starting position:
Lying on the side, lower arm is angled in front of the body, head is supported (towel). Elbows rest against the body. Upper arm rested on the side of the body. 

Execution of movement:
Lift weight up to the body and hold it up for about 3 seconds. Lower slowly. Tip: Think of the movement of a door joint. Upper arm and shoulder together form the joint whilst the lower arm represents the door. Open and close the door via the rotator muscles of the shoulder.  
– 20 repetitions
– 2 sets
– 2 min break

b.) External rotation

Antagonist Training climbing shoulder
Antagonist Training climbing shoulder

Starting position:
Lying on the side. Elbows resting on hips. Forearm in front of the belly with weight in hand. Head supported. 

Execution of movement:
Lift the weight slowly into a horizontal position. Hold briefly and lower again. Make sure that the elbow remains on the floor. 
– 20 repetitions
– 2 sets
– 2 min break

Variation: Shoulder rotation with the Theraband:

Antagonist Training climbing shoulder

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4. Disc circle

Antagonist Training Bouldering climbing
Move arms behind the back…
Antagonist Training Bouldering climbing
…in a circular motion

Starting position:
Lie on the stomach and tense back (buttocks, back extension). Arms stretched forward. Looking at the mat. 

Movement execution:
Take the weight in one hand and move it from the starting position in a large circular movement (arms stretched out) behind your back. When you reach the front again, transfer the weight to the other hand.

Maintain body tension, work slowly and concentrate on even breathing. 
– 10 repetitions then change direction

5. Chair pose

Ideal exercise to train the back extensors and to maintain an upright posture or to counteract climber’s back. 

Antagonist Training Bouldering climbing
Keep your back straight!
Antagonist Training Bouldering climbing
Red = Muscles used

Starting position:
Legs shoulder width apart with toes pointing slightly outwards. Keep the knees at a 90-degree angle and bend the hips about 45 degrees (see picture). Stretch arms in line with body over head. Thumbs point upwards.  

Execution of movement:
Stretch arms and press upwards or keep them static in line with the body. Additional weights can be used. 
– Hold for 20 seconds
– 2 minutes break

6. Superman

Training of the entire back extensor muscles, especially the lower back and the upper inner back. Straighten your body and pull your shoulders back. This is an ideal balancing exercise for climbers and boulderers. 

Antagonist Training climbing back
Antagonist Training climbing back
Keep the tension

Starting position:
lying face down on a mat with arms stretched forward over the head, legs and toes stretched and the head in line with the spine. 

Execution of movement:
Simultaneously lift one arm and the opposite leg as far as possible (without swinging!). Hold for 5 seconds, lower and change. Make sure the movement is controlled.
-20 repetitions

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Antagonist Training – Chest, Shoulder and Triceps

The main antagonists of every climber are the deltoids (shoulder), the pectorals (chest) and the triceps (arm extensors).

The first two exercises (push-ups and butterfly) work the chest portion of the body whereas shoulder lifting and handstands are very strenuous on the shoulders. All exercises train the antagonists and ensure balanced and healthy muscles and posture.  

Antagonist Training climbing
Chest – Shoulder – Triceps


The classic compensatory exercise for climbers.
All major antagonists typical of climbing can be trained (burst, arm and shoulder muscles as well as holistic body tension). Push-ups can be adjusted according to strength and ability, are easy to do with endless variations.  

1. Classic

Antagonist Training climbing
Antagonist Training climbing

Starting position:
Place arms stretched out and shoulder width in front of chest on floor. Position yourself on your toes and keep body straight (body tension). 

Execution of movement:
Lower body slowly (until just before touching the floor) and press up again. Body forms a line (do not lift buttocks)! 

The position of the hands can and should be varied in principle:

  • Hands further apart: trains chest muscles
  • Hands closer together: trains triceps and elbow extension
  • The higher the legs the more difficult the exercise
  • The higher the arms the easier the exercise

2. Push-up variations

Climber Push Up 1
Climber Push Up 2
Variation Hands

Super Push Up 1
Super Push Up 2
Super Push Up 3

Wall Run 1
Wall Walk 2
Antagonist Training climbing
Wall Walk 3

Butterfly: (TRX, Rings)

Trains the muscles responsible for pushing that are under-utilised when climbing. In addition to the front shoulder muscles, this exercise primarily trains the chest muscles. Due to the instability of the rings, the body tension is trained at the same time. 

Adjunct Compensatory Training Bouldering
Starting position
Adjunct Compensatory Training Bouldering
End position

Starting position:
Adjust the respective ring to hip height. Hold the handles and walk approx. 1 metre backwards. Support the handles with outstretched arms. Body remains stretched and tensed. 

Correct movement:
Move the handles slowly and evenly apart and lower the body between the handles (chest at hand level). From here, perform the same movement in reverse back to the starting position. Pay attention to body tension and slightly angled arms to protect sustaining injury to the elbows. 

Adjust the difficulty by adjusting the grip height and angle of the elbows. 
– The more horizontal the body the more difficult the exercise.
– The straighter the ams the more difficult the exercise.


The handstand mainly trains the antagonist muscles of the shoulders and arm extensors; however, body tension and coordination are trained at the same time. 

Antagonist Training bouldering
Antagonist Training bouldering
Handstand – Variation

Starting position:
Place both hands on the floor about 30 cm in front of a wall. Use legs to position yourself in a lunging position.

Execution of movement:
Jumps off the floor and catapults the legs upwards towards the wall. The stretched leg touches the wall first. Press up from the shoulders and maintain body tension (do not curve the back).
– Hold the handstand for 20 seconds.

Shoulder Press

The movement of shoulder press is the ideal compensatory exercise, as it addresses the muscles otherwise less often used when climbing. 

Adjunct Compensatory Training Bouldering
Adjunct Compensatory Training Bouldering

Starting position:
Sitting upright (bench with backrest) with feet flat on the floor. Dumbbells kept lateral at shoulder level with palms pointing forward. 

Execution of movement:
Exhale and lift the dumbbells evenly in an upward motion until they touch. Keep palms forward. Slowly release to starting position. 
– 15-20 repetitions
– 2 sets

Tricep Dips

The triceps dips mainly train the arm extensors and chest muscles. In addition, this exercise has climbing specific advantages, namely when you have to push your way up to the top of a ledge, as is often the case when climbing out of a boulder (Mantle).

Climbing Adjunct Compensatory Training
Climbing Adjunct Compensatory Training

Starting position:
Position yourself between the rings, chairs or loops. Jump up and keep your arms stretched out in the starting position. 

Execution of movement:
Slowly lower until arms are angled 90 degrees (do not lower further down) and immediately push up again to the starting position (If this exercise is still too difficult, you can help a bit with your legs). 
– 10-15 repetitions
– 2 sets

The rings or TRX bands have the added advantage of being unstable, which means that the shoulder and scapular stabilisers, as well as parts of the back and overall body tension, are also trained. 

Alternative exercise:

Climbing Adjunct Compensatory Training
Climbing Adjunct Compensatory Training

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Climbers and Bad Posture – Antagonist Training

The climber’s Hunchback is a typical example of muscular imbalance.
Due to the one-sided stress of climbing, both the traction muscles (e.g. latissimus dorsi and teres major muscle) and the abdominal muscles are strengthened disproportionately. Furthermore, the pectoralis minor is responsible for the imbalance. 

Antagonist Training climbing posture
Climbers Hunchback
Antagonist Training climbing posture
“Normal” posture

The pulling muscles become stronger and stronger and sooner or later pull the shoulders forward, turning the arms inwards. A hunchback is what remains.

Measures to combat climber’s back

1. Antagonist training

Selected parts of the back muscles (trapezius, rhombic muscles) as well as shoulder muscles (deltoid muscle) and chest muscles must be strengthened. 

Compensatory exercises:

BackChest & Shoulder
T-Y exercisesPush Up
Scapular Pull UpsButterfly
Scapular Push UpsHandstand
RowingShoulder Press
Disc CircleDips
Chair Pose
All exercises are explained in detail above

For more information about postural deformities and climber’s back, see Postural Deformities and Climbing: Causes and preventative measures.
Here you will also find out why you should always use belay glasses.

Climbing posture climbers back bouldering
Fix and prevent – postural deformities

2. Stretching

In addition, stretching of the shortened muscles leads to a healthy posture

  • Pectoralis minor
  • Abdominal muscles
  • Back and shoulder strap

3. Upright posture

Assuming an upright body position and a good, healthy posture (shoulder blades back, upright to the top) will strengthen just the right muscles and thus effectively counteract climber’s back.

Best of all, you can train these muscle groups all day long (sitting, walking, standing and even lying down).

The 7 most important stretching exercises for climbers.

1. Hand and finger flexors

a.) Stretch inwards (with the thumb facing the body)

Antagonist Training climbing stretching
Inward stretching

b.) Stretching outwards (palm away from the body) 

Antagonist Training climbing stretching
Outward stretching

Pay attention to stretched elbows. Stretch for about 20 seconds.


Antagonist Training climbing stretching
Starting position
Antagonist Training climbing stretching
End position

Hands flat on the floor, fingers pointing to knees (elbows stretched)- Lower buttocks slowly till you feel the stretch in the forearms.

2. Hand and finger extender

Important to avoid elbow problems. This stretching affects the extensor muscles as well as the flexor (Musculus brachioradialis), which is subject to heavy strain. 

Climbing Adjunct Compensatory Training stretch
Stretch – right arm
Climbing Adjunct Compensatory Training stretch
Stretch – left arm

Interlock the fingers in front of the body (palms together) and actively stretch with one hand at a time. Keep shoulders down and pay attention to stretched arms. 

3. Stretching of shoulder and back

These exercises stretch especially the upper back and the entire back and shoulder muscles (trapezius and rhombus muscle)

Climbing Adjunct Compensatory Training stretch
Climbing Adjunct Compensatory Training stretch

cross forearms, elbows at right angle, shoulders remain low (do not lift)

Towel Exercise

This compensatory stretching not only increases flexibility but also the range of motion of the shoulder joint and is essential for every climber. 
Instructions: Roll up a towel and hold the top end behind the head. Grip the lower end with the other hand (palms backwards). Using the upper hand, pull the towel upwards until the shoulder of the lower hand is stretched.
Hold position for 20 seconds. 

Antagonist Training Bouldering climbing

4. Compensatory stretching – chest muscles

In addition to increased range of motion in the shoulder, the main focus here is on stretching the pectoralis minor muscle (pulls the shoulders down to the front, climber’s back).

Antagonist Training Bouldering climbing
Antagonist Training Bouldering climbing

Use a towel or rope to help. Grip the rope as far apart as possible to allow for one complete movement (arms stretched out during the whole movement). The further apart the hands are, the easier the exercise becomes. Stay upright and perform the movement slowly and above all evenly (both arms simultaneously backwards).

5. Stretching of the abdominal muscles

Antagonist Training Bouldering climbing
Antagonist Training Bouldering climbing

Lie on your stomach, place hands (or forearms) on sides of shoulders. Tense buttocks and slowly lift shoulders from floor (hips and legs remain on floor) until abdominal muscles are stretched. Hold for 20 seconds and lower.

If you have disc problems or pain, please stop this exercise immediately. 

6. Stretching and mobility of the hip muscles

Hip flexors

Antagonist Training Bouldering climbing
Antagonist Training Bouldering climbing

Kneeling on the ground, front leg set up at a 90-degree angle. Push hip forward to increase the stretch in the hip flexor. Place hands on front knee. Upper body upright and straight. Look forward. 

7. Compensatory stretching of the Piriformis

The Piriformus belongs to the external hip rotators and is put under a lot of strain when climbing (used to climb up steps that are positioned upwards and outwards). Stretching prevents imbalance and leads to increased mobility in the hip area

On all fours. Left knee to the left-hand side with the lower leg ideally at a 90 degrees angle (I personally cannot manage 90 degrees) in front of the body. Stretch back leg and push the hip down. (Hip remains in the horizontal position) 

Antagonist Agonist briefly explained:
The agonist executes a movement, while the antagonist ensures that the movement can take place in the opposite direction. 
The easiest way to explain this is by using biceps and triceps. The biceps flex the forearm (arm flexor) at the elbow, while at the same time stretching the antagonist (triceps, arm extensor). 

Muscular imbalance explained briefly:
Due to one-sided strain (pulling movement when climbing), the strained muscles become stronger whilst the antagonist muscles become weaker. 
This imbalance has a negative effect on posture and skeleton and leads to muscle overloading, which can ultimately lead to injuries and entail a longer climbing break.

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Strong vs. weak climbing muscles

Bouldering Adjunct Compensatory Training
Red = heavily used – Green = little used

Strong muscles

Forearm flexors
The forearm flexor muscles are responsible for flexing the fingers and wrist. This means maintaining all holds while climbing. Complete forearm flexor muscles (hand and finger flexors)

Those parts of the back muscles that ensure that we can: a.) pull ourselves up (pull-up) and b.) pull ourselves towards the wall.  
Latissimus dorsi muscle (Musculus latissimus dorsi)
Teres major muscle (musculus teres major), subscapularis muscle (musculus subscapularis) and the infraspinatus muscle (musculus infraspinatus).

Arm Flexors
The arm flexors or elbow flexors are involved in all pulling movements (chin-up), just like the latissimus. The biceps are not put under so much strain because the palms of the hands usually face the wall when climbing.  
Elbow flexor (Musculus biceps brachii
Brachialis muscle (Musculus brachialis) and brachioradialis muscle (musculus brachioradialis)

Those parts of the shoulder muscles that pull the arm downwards or stabilise the shoulder blades during pulling movements. Also responsible (incl. posterior muscles) for the internal rotation of the shoulder.  
Posterior deltoid muscle (Musculus deltoideus) Trapezius muscle (Musculus trapezius) Subscapularis muscle (Musculus subscapularis) Infraspinatus muscle (Musculus infraspinatus)

The pectoralis minor pulls the shoulder downwards in a diagonal motion is partially responsible for the cause of climber’s back.  
Pectoralis minor muscle (Musculus pectoralis minor)

Abdominal muscles
Abdominal muscles provide body tension and are therefore important for climbing. They are the link between arms and legs and ensure that we can put the right amount of weight into our mounts or hold ourselves up against steep walls.  
All abdominal muscles.

Hip flexor (Musculus psoas major
Legs: Here it is mainly the calves and toe flexors as well as leg bending muscles that are used. Calves and toe flexors are used to mount a surface and the leg flexors to “pull against the wall” or for hooking.  
The triceps surae muscle (Musculus triceps surae), flexor hallucis longus muscle (Musculus flexor hallucis longus) as well as biceps femoris muscles (Musculus biceps femoris) form the entire calf muscle. 

Weak muscles

Forearm extender
Those muscle groups responsible for the extension of the fingers and wrist.  
– Total forearm extensor muscles (finger and wrist extensors)

The muscles in the upper back are responsible for retracting and stabilising the shoulder blades and raising the arm. The lower back is responsible for straightening and stretching the upper body.
The trapezius (Musculus trapezius, upper and middle part) rhomboid major muscle (Musculus rhomboideus major)

Arm Extension
Muscle groups that are responsible for stretching in the elbow joint.  
Elbow extensor (Musculus triceps brachii) Anconaeus muscle (Musculus anconaeus)

Shoulder muscles used for pushing and lifting the upper arms. 
– Anterior deltoid muscle (Musculus deltoideus)

The muscles that are responsible for pressing movements. (Upwards or forwards). Lower and middle chest muscles. 
Pectoralis major muscle (Musculus pectoralis major)

Back extender
That part of the back that is responsible for straightening or stretching the body. 
Lower back/All back-extensor muscles (Musculus erector spinae)

The legs are not stressed as much whilst climbing insofar as to suggest that they may need a special compensatory training. Those regularly engaging in other sports besides climbing and bouldering will have no problems. However, given that climbers do have comparatively thin legs (when comparing to their upper bodies), it does not hurt to train the legs every once in a while.

More about Antagonist training for climbers.  

How often should I do compensatory training or antagonist training?
Depending on the amount of training you do, you should seek to engage in a compensatory training or stretching exercises between 2-4 times a week. It takes relatively little time and can be done within 20-30 minutes.

Which training equipment do I need for a climbing-specific training?
A comprehensive compensatory training can be done without any special training equipment. But if you want to refine your training, I recommend the following equipment:

  • Ring trainer (rings or TRX)
  • Theraband (resistance bands)
  • Pull-up bar
  • Minibars (handstand, push-up, etc.)
  • Blackroll (foam roller)