Now that you've established how often you can go to the gym, and how you'll divide your time when you're there, you can start to pick your exercises.
I won't go over individual exercises, but instead talk about the different types of equipment, and a couple other things to consider when deciding which will work best for your goals.
Picking your equipment
There are three basic types of equipment at the gym: fixed machines, cables and free weights. Your routine may only use one type, or a combination of all three. That part is entirely up to you. There's a ton of literature out there about the advantages and disadvantages of the type of equipment you choose to work with if you want to delve deeper. But if you're just getting started you really just need to know the basics which I've outlined below.
In most gyms these are often located close by one another and sometimes in the shape of a circuit. Many gyms will in fact advertise a pre-selected group as a "quick 30 minute circuit."
Machines are great for beginners who have little familiarity with exercises and are working out on their own. These machines will often have a picture of the muscles they target, as well as instructions on how to complete the exercise. This makes them a pretty safe option as no spotter is necessary. It's also hard not to do the exercise properly making them low risk for injury. And finally, they'll also overload the muscle through its full range of motion.
These machines don't usually have much give on positioning, so it can be harder to properly accommodate different body sizes. They also aren't versatile, so you can only do the exercise the machine is designed for. And finally they don't allow the body to develop neuromuscular coordination (more on this below).
You might still consider these "machines" but the distinction is usually that attached to the weight stack you can actually see a cable or pulley. On most you should be able to change out the type of "handle" on the end of the cable to accommodate the type of exercise you plan to do.
Cables are more versatile than fixed machines as you can do variety of exercise on them by simply switching a few positions. They are also safer than free weights as all the weight is still fixed to the machine. There are also certain muscle groups and movements that are tricky to properly overload with free weights, so cables are good to fill in those gaps.
Unlike the more fixed machines, these ones don't actually properly overload the muscle through its full range of motion. And not unlike other machines, they aren't training neuromuscular coordination.
This category basically includes dumbbells, barbells, kettlebells, and all other forms of weight not attached to something.
Similar to the cables, free weights are versatile, and there are a variety of exercises you can do with them. The other big advantage they have over other equipment is that free weights help to develop neuromuscular coordination. Think of it like this: when you use a machine you're acting in some way against the weight, but as you do that, the weight will only go up or down. It's fixed. Your body doesn't have to try and keep it on the proper path, it can just focus on pushing (or pulling) it in its desired direction. With free weights on the other hand, the path that weight takes is entirely up to you. Not only are you focusing on the movement you want to achieve, but you now have to ensure your movement is fluid and stable. As your body works to overcome this added challenge it develops neuromuscular coordination. In addition to pushing the weight, you are also teaching your body to do an exercise. This is also why you want to avoid loading yourself too heavy before your body knows how to actually complete the movement.
Because of the above, this makes free weights more dangerous if you don't know what you're doing. There are also certain exercises that if you're looking to push some pretty heavy weight, the absence of a fixed path (as noted above) can keep you from the load you may be able to achieve on a fixed machine or cables. There are also certain muscle groups that are hard to isolate with free weights. All these considerations are why a combination of all three is usually the best way to structure your workout.
Choosing your order: things to consider
And finally another consideration when picking your exercises is what order you'll put them in. For the most part this can be based off personal preference but there are some general rules to consider.
1. Work bigger muscles groups first before isolating smaller ones.
This good practice for a variety of reasons, but the main one being if you are doing isolation exercises in your workout (i.e. bicep curls or tricep press) this will ensure that those bigger muscle groups that might jump in to "assist" the smaller ones are good and fatigued by the time you get to the small ones. Ordering them this way will help maximize your isolation.
2. Save abs for the end.
In theory, our core should be engaged throughout our workout to assist with proper form. If you burn out your core at the start of your workout, you could end up sacrificing your form, and bad form leads to injuries.
3. When to put cardio before weights.
If you plan to put a strength session in the same gym visit as a cardio workout, you should consider your goals before deciding which to do first. If you are really trying to work on improving strength then you'll want to do your weights first to ensure you aren't fatigued by the time you get to your strength portion. If you are training for an endurance event and your cardio will need to be the focus of your energy, then put it first. Really it boils down to where is your energy the most important as you'll put that component first.
Now that you've thought about the exercises and their order, the next step is to think about the number of reps and sets, and how to keep track of it all. In the next post I'll go over how to choose those numbers based on your goals.