To start, this is not an ideal routine. I would strongly suggest using free weights instead of bodyweight both for the best results and to remain safe.
This routine may be acceptable under rare circumstances in which you have minimal equipment.
Fitness can develop with little equipment. Bodyweight training works. The exercise our bodies adapted for did not come about by using complex machinery. If anything, an extensive gym can distract. It draws your attention away from the simple yet most productive free weight and bodyweight training exercises.
Modern inventions often require our bodies to work in unnatural ways. This can harm us and reduce our results. We adapted instead to the demands imposed upon us. This means using multi-joint motions that recruit lots of muscle to handle heavier resistances. Heavy resistance in the real world meant dealing with free weight and bodyweight training possibilities.
Although strength training does require greater loads, you can use bodyweight training options along with other simple tools. Resistance is resistance. Strength and endurance share a relationship within a reasonable range. This means doing more reps will make you stronger. Bodyweight training exercises for high reps can build muscle and strength.
The Big Three
You cover all the major muscle groups with a squat, push, and a pull for bodyweight training. You can perform the exercises at a local park or in your living room. The push and squat can work anywhere. The pull requires some basic equipment. You can perform a step-up or squat, push-up or dip, and finally a row or pull-up as the selections.
The lower body choices focus on one leg at a time. This allows your bodyweight to give more resistance. The push-up is a simple motion. Do not elevate your feet to make the exercise more difficult. This changes the leverage in a way that feels tougher on the joints. Many suggest altering your leverage to make an exercise harder. I recommend against this decision. This may place your joints in a compromising position. It makes it harder for the wrong reasons.
The dip can add substantial resistance due to the elevation from the ground. Unfortunately, it can damage the shoulder. They also require parallel bars, or at least two objects that allow you to place your hands apart while elevated. Two solid chairs can work well. Lean forward when performing these to minimize shoulder depression, and avoid it if anything hurts. For the row, use an object you can grasp. For the pull-up, find an overhead bar.
Getting the Heart Rate Up
Follow the strength training with intervals. Conditioning can involve stairclimbing, running hills, sprints, etc. You now have a thorough bodyweight training workout. Equipment adds variety and keeps things exciting. Variety as a concept in fitness comes overrated though. Hammer the basics consistently and progressively. You will achieve results that will astound most people.
Disadvantages
Bodyweight training does have disadvantages.
Certain trainees may struggle to perform the exercises at the minimum possible weight. Beyond an unknown range, the repetitions and load relationship begins to deteriorate. Intuitively we know that training for a mile differs from training for a heavy squat. This occurs due to the way our energy systems work among other factors.
This need for resistance grows as you develop strength. Prolonging the duration for each exercise will make your training less specific to muscle and strength growth. You will have to find a way to add resistance once the repetitions exceed 30 in most cases. Taking short breaks during a set may help with the lactic acid buildup that will limit the set. You may have to find a backpack and add weight to it. Wear this during some exercises. Hold weights for the lower body choices.
The Simple Bodyweight Training Program
Here are possible bodyweight training routines anybody can perform. Exercises progress in difficulty, but the later ones do not always represent the best picks. Choose the hardest ones you can perform safely:
Warm-Up: 3-5 minutes walking, stretch if needed
Kneeling Push-Up, Push-Up, or Dip: 1-2 warm-up sets of 3-5 reps, 1 working set with as many repetitions as possible.
Step-Up, Split Squat, or One-Legged Squat: 1-2 warm-up sets of 3-5 reps, 1 working set with as many repetitions as possible.
Row or Pull-Up: 1-2 warm-up sets of 3-5 reps, 1 working set as many repetitions as possible
Conditioning: Alternating Jog and Walk, Stairclimbing, Hill Sprints, or Burpees: 3-5 minute HIIT intervals
Cool-Down: Perform if needed
Do this routine twice a week. Always seek to add reps or weight. If you stay consistent, you will achieve results far beyond most. This includes those working out in commercial gyms most days of the week and doing bodybuilding splits with fancy equipment.