training

If you don't have a gym, there are still plenty of exercises that you can do that can make you a stronger climber.

Depending on where you live, your best bet may be to just find a playground, they usually have pull-up bars and other equipment that you can do some body-weight exercises.

You can do pull-ups and all of its many variations. Push-ups and all of its variations. Running, sprinting, or jogging for legs. You can also do squats and calf raises, which are great.

You can also either buy or make a hangboard and a pinch block. These are the two classic climbing exercise equipment. The pinch block would be the easier to make, or the cheaper to buy, it's really just a block of wood with a hole in the middle of it to attach a rope and weights to it. The only issue is that you need weights for this to be effective, or something heavy that you can attach to it, like a heavy rock.

Other than that, if you can get a hangboard, that will be your next best option. Hangboards are used for training your fingers by hanging from them from your fingertips. Be warned though that it is very easy to injure yourself on hangboards, and most suggest only doing it after 1 year of climbing.

I always go for body weight exercises. There are always exercises that you can do to challenge yourself and that you can find hard, like learning to do handstands and doing handstand push-ups.

The real question would be if planks are good for your core.

Your core is very important for climbing as it is used in almost any climbing move, and can really help make you a better climber. It helps stabilize you, it can help keep you closer to the wall, and it can help you move in ways that without core strength would be very, very difficult.

So, core strength is very important for climbing, now the question is if planks are a good core exercise, or if it has little effect on the core.

Based on what can be found online, many people suggest doing planks instead of other exercises such as crunches due to less strain on the spine.
Planks work your back, shoulders, abs, legs and arms, all at the same time, while putting less strain on your spine, which is why many people recommend it.

Whether there are other exercises that are better for core strength than planks is another question, but based on what experts say and on research that can be found online, doing planks is a great exercise for core strength, which should translate to being a great exercise for climbing since climbing requires a strong core.

There is no real rule as to how flexible you need to be for climbing, but, being flexible can really help a lot in climbing and in solving the problems. It gives you more tools to use on the wall to finish the routes.

Having basic flexibility and a full range of motion is a good starting point, and building on that can get you a long way in climbing.

If you are not flexible, though, don't think that you won't be able to climb hard routes. I have known many people who cannot touch their toes even with slightly bent knees, and they can climb v7/v8.
On the other hand, I know some climbers who are very flexible and that are relatively beginners, they normally climb v5/v6, but sometimes they are able to top some v7s due to their flexibility. It just gives them that additional advantage.

Being flexible can also help prevent injuries. Some routes require a low level of flexibility, and others may require quite a high level of flexibility. Working on routes that require a level of flexibility that you do not have could result in injury.
Being flexible in general also just helps prevents injuries.

Squats are great for building general leg strength, while also working many other upper body muscles.

Another great exercise is sprinting. Sprinting can really push you to your limits and give you that leg power you are looking for.

Pistol squats is another great exercise that is very popular among climbers. It's very similar to regular squats, but also quite different, as you will need to put extra effort in balancing yourself on one leg in order to do the squat. To make it easier, you can do it while standing on the edge of a box, and performing the squat there. Part of the difficulty in the pistol squat is doing the squat with your other leg extended out front. So, by minimizing the amount that leg must be out front will make the squat easier to perform, and this is done by standing on something tall.

Calf raises are a great exercise and a personal favorite for building and strengthening the calf muscles. It is also one of the easiest exercises that can be performed. All you need is a step, this can be a staircase step, a weight that you stand on, or anything else with an edge that you can stand on and have your heel touch the ground. Just make sure that what ever you are standing is tall enough so that your calf muscle will actually be extended when your heel touches the ground. To do the exercise, stand on the edge with your toes, lower your heel to the ground, and lift yourself up slowly, hold at the top for a second, and then lower yourself slowly, and repeat.

The bottom line is that building leg strength for climbing is just like building leg strength in general, really. In climbing, you use your legs for certain hooks, jumps, dynamic movements, and stabilization, all of which require general leg strength in most or all of your main leg muscles. The exercises above will work those muscles.

It is also important to keep in mind that climbing itself activates certain muscles that may not be activated in other exercises, and they may be used in certain ways and conditions that are hard to replicate outside of climbing. These situations are also important for training and strengthening your muscles, and not just your leg muscles, so keep on climbing, and add the additional leg exercises as a supplement to your climbing.

Training for climbing does not actually require a gym, you can train for climbing from almost anywhere, including your home.

Keep in mind that you should be extra careful with these exercises to not overdo it, and to not injure yourself.

1. Pull-ups
Pull-ups, as you would imagine, can be very beneficial to your climbing. Try to do pull-ups with body weight. Set a goal, and once you reach that goal, try and add more weights if available. If you do not have additional weights, try different variations of pull-ups, such as a wide grip, narrow grip, hammer grip (palms facing each other), mixed grip (once palm facing out and the other palm facing in), towel pull-ups (more about this below), and anything else that comes to mind.

2. Towel pull-ups
Towel pull-ups are a great way to train your grip and pull-ups at the same time. It also allows you to train the one arm pull-up. To do this, simply take a towel and toss it around a bar. Grab each end of the towel, and start doing pull-ups. Having 2 towels (one per hand) may be more comfortable.

To add the extra challenge of training the one arm pull-up, unbalance the towel by making one side higher and one side lower. This will cause an imbalance in the grip, which will cause one arm to pull harder than the other. Try to lower one arm as much as possible to put more weight on the pulling arm (you can do this with a band also, this will give you more room to lower your hand and to train different positions).

3. Push-ups
Though many people think that chest muscles are not needed for climbing, they actually are needed, and it is important to train them to balance your muscles out to prevent serious muscle imbalances, which could have negative effects such as poor posture.

Push-ups are a very basic and easy exercise to perform, and it's one that can be done almost anywhere. To make the exercise harder, perform different variations of, such as wide hand position, close hand position, one hand higher and one lower, adding weights to your back if available, raising your feet (you can go all the way to a hand stand with this if you are capable).

4. Dips
Another great chest and triceps exercise if you have a set of parallel bars. Just like the other exercises, if you have some weights available (or even a heavy rock or water bottle), try adding them to the exercise for extra difficulty.

5. Squats, calf raises, and sprinting
Just like with chest and triceps muscles, legs are also very important to train in order to prevent imbalances, and legs are in fact used and important in climbing.

Squats are a great way to develop leg strength and mobility. You can do it with body weight, or add additional weights if available, or do different variations of it, such as jumping high when reaching the top of the squat.

Calf raises are great for training the calf muscles, just find an edge, put your toes on it, lower your heel to the ground, and just raise yourself as high as you can from your toes, hold for a second, and lower.

Sprinting is a great all-round leg exercise that really pushes you to your limit and can show a lot of results.

6. Pinch blocks
Forearm strength and grip strength can be trained in many different ways, especially outside the gym. One of the best ways to train them is by using blocks such as a pinch block.

What this is, is simply a block, usually made of wood, with the option to attach weights to it by a rope. All you do is pinch the block, and lift it off of the ground, hold it for 7-10 seconds, and then lower it, rest, then repeat.
It really is one of the simplest forms of training grip strength that is very specific and beneficial for climbing, and one of the exercises that shows the most results.

Pinch blocks usually have multiple gripping options, such as a narrow pinch, and a wide pinch.

7. Hangboarding
Another classic, though one that comes with quite a bit of a warning from most climbers.
Hangbaords are simply boards with edges of different depths. They are usually hung above doors or in training rooms, and all you do is hang from them from your fingertips for a certain amount of seconds, depending on the training program you are following.

Adding weights to this exercise is also an option, as is training hanging from one hand.

The warning that most people give when it comes to hangboarding is to not try it unless you have been climbing for at least a year. This is because hanging from your fingers is very heavy on your tendons, which are different from muscles. They take longer to adapt and to get stronger, and they also take longer to heal from injuries. Climbing helps condition your tendons and makes them stronger and able to handle heavier loads with time. If you skip the climbing part and go straight to hangboarding, or you start hangboarding before your tendons are properly conditioned, you may be increasing your risk of finger injuries that may take many months to heal.

8. Playgrounds
Find a local playground, they usually have many different training options such as pull up bars, parallel bars, and more.
Exercises that utilize body weight are great for climbing, and playgrounds are usually full of options for body weight training, so it is a safe bet.

9. Yoga and other classes
Training doesn't have to be in the form of lifting anything, it can also be in the form of Yoga and other similar classes. If you have never done Yoga before, you may be surprised at how difficult it is, especially on the core, which is a great reason to include Yoga into your training since climbing very heavily relies on core strength.

10. Flexibility
Flexibility is considered by many as a secret gem in climbing, since many people don't think it's very important, or they know it's important, but just don't like doing it.

Being flexible gives you a wide range of additional moves on the wall. This comes into play many times, especially on the much harder routes, where finding the right beta for you is difficult. I have seen in numerous occasions how flexibility was the key attribute that allowed climbers to climb their projects. So if you don't have access to a gym for some time, training flexibility is a great use of that time, and something that should be done on a regular basis regardless of whether the gym is closed or not.

Rock climbing can actually be pretty heavy on the shoulders, as they are used in almost all climbing moves, so it makes sense that your shoulders will be strengthened from climbing.

Whether climbing will give you broad shoulders though is another thing. While it's true that climbing will strengthen your shoulders just like any other muscle strengthens due to training, the amount at which your shoulders will grow bigger doesn't depend just on climbing, but also on your body in general and if you also do other exercises and training.

It's very common to see skinny climbers who don't have much muscle mass climbing some of the harder, double-digit routes (v10+ for example), but, it's also common to see bulkier climbers also, some would say that their size comes only from climbing, some will say that it's a combination of climbing and weight training or other combinations.
So some very experienced climbers may not have that much muscle mass, while others may.

In the end, it depends on you and your body. If your goal is to get broader shoulders, then you could try adding weight training to your schedule, if you do not want broader shoulders, you can try just climbing and seeing what that does for you.
It's really very individual and requires experimentation to figure it out.