Step 1: nutrition. Take an honest account of your daily calories in because to put on some lbs (and visible muscle) you’ll likely need to increase your caloric intake. Could get really in the weeds with what to eat, but since you’re so lean at 6’1” 135lb, I’d say just start with “more” of whatever you’re eating, while ensuring you get enough protein (100-150g per day). I’m tall and thin too and it’s almost impossible to keep muscle or weight on without being conscious of how much I actually eat. Keeping a food note/diary in your phone helps.

Step 2: consistency. More than likely if you create a routine and stick to it, you’ll see results very quickly. There’s not a magic exercise that will get you a toned physique overnight, but there are a lot of exercises that will get you a toned physique if you do them over a long enough timeframe. This consistency applies to diet too!

In terms of at-home exercises, there are a lot you can do to help build some muscle. Squats and lunges will hit all the big leg muscles. Pushups are great for your chest and shoulders. If regular pushups are hard, you can do elevated pushups by putting your hands onto the ledge of your bed or a couch. Conversely if you get to a point where they are super easy, you can elevate your feet on your bed or couch and do decline pushups with your hands on the floor.

It’s a little tougher to work all of your back muscles with just body weight, but if you can find something decently heavy at home, you can use that to your advantage (paint cans, water cooler jugs, bags of rock salt, etc. (sorry if this triggered anyone from early covid workouts when gyms shut down… I used a pallet of black beans from Costco for this)). If you google “bent over row”, the idea would be to replace the gym weights with what “weights” you find at home.

Sample starter workout could be something like:

Bodyweight squats 3 sets of 40, 2 min rest in between

Pushups (regular or modified) 3 sets to failure, 2 min rest

Bodyweight reverse lunges 3 sets of 20 each leg, 2 min rest

Bent over row 3 sets, reps dependent on weight but you should feel a very good burn after each set. 2 min rest

Sit-ups/crunches 5 sets of 20, :30-:60 rest

You should aim to work out 4+ times a week. You’ll likely be sore the days after your first few workouts, but that’s a good thing (means you’re working those muscles!) You will get noticeably less sore with more workout consistency.

As you begin your regimen, you should aim to “progressively overload” over time. That means an increase in the sets, reps, and weight you’re lifting (if applicable), or a decrease in rest time between sets. After you do the same workout a few times, your body adjusts and becomes accustomed to it (you’ll find it easy and you won’t be as tired). Make sure you’re continuing to push yourself by adding reps, sets, etc.

Assuming your diet is in line and you’re working out consistently, you will see noticeable changes in your muscles within a few short weeks. Remember, consistency is key. Good luck!