Lisa Whitney, a dietitian in Reno, Nev., came across the deal of a lifetime about two years ago. A fitness studio was going out of business and selling its equipment. She scored an indoor exercise bike for $100.

Ms. Whitney soon made some additions to the bike. She propped her iPad on the handlebars. Then she experimented with online cycling classes streamed on YouTube and on the app for Peloton, a maker of internet-connected exercise devices that offers interactive fitness classes.

Ms. Whitney had no desire to upgrade to one of Peloton’s $1,900-plus luxury exercise bikes, which include a tablet to stream classes and sensors that track your speed and heart rate. So she further modified her bike to become a do-it-yourself Peloton, buying sensors and indoor cycling shoes.

The grand total: about $300, plus a $13 monthly subscription to Peloton’s app. Not cheap, but a significant discount to what she might have paid.

“I’m happy with my setup,” Ms. Whitney, 42, said. “I really don’t think upgrading would do much.”

The pandemic, which has forced many gyms to shut down, has driven hordes of people to splurge on luxury items like Peloton’s bikes and treadmills so they can work out at home. Capitalizing on this trend, Apple last year released Apple Fitness Plus, an instructional fitness app that is exclusively offered to people who own an Apple Watch, which requires an iPhone to work.

But all of that can be expensive. The minimum prices of an Apple Watch and iPhone add up to $600, and Apple Fitness Plus costs $10 a month. Then to stream classes on a big-screen TV instead of a phone while you exercise, you need a streaming device such as an Apple TV, which costs about $150. The full Peloton experience is even pricier.

With the economy in a funk, many of us are trying to tighten our spending while maintaining good health. So I experimented with how to minimize the costs of doing video-instructed workouts at home, talked to tinkerers and assessed the pros and cons.

Here’s what I learned.

The Pros and Cons of Free

To start my experiment for working out at home on the cheap, the first question I tackled was whether to subscribe to a fitness app or stream classes from YouTube for free. Both largely provide videos of instructors guiding you through workouts.

So I bought an $8 yoga mat and a $70 pair of adjustable dumbbells and turned on my TV, which includes the YouTube app. I then subscribed to three of the most popular YouTube channels that have free content for exercising at home: Yoga With Adriene, Fitness Blender and Holly Dolke.

One immediate downside was almost too much content — often hundreds of videos per YouTuber — making it difficult to pick a workout. Even when I finally chose a video, I learned I had to brace myself for some quality issues.

In the Yoga With Adriene channel, for instance, I selected the video “Yoga for When You Feel Dead Inside,” which felt appropriate for the time we are living in. The video looked good, but at times the instructor’s voice sounded muffled.

Production problems were more visible in the Holly Dolke channel, which has a collection of intense workouts that you can do without any equipment. When I tried the video “Muffin Top Melter,” an instructor in the background demonstrated how to do a more challenging version of each exercise, but the other instructor, in the foreground, constantly blocked her.

Then there were the ads. As I lifted weights while following a 10-minute fat-burning workout from Fitness Blender, YouTube interrupted the video to play an ad for Dawn soap. That left me holding a dumbbell above the back of my neck while I waited for the ad to end.

Those issues aside, I was able to do all of the exercises demonstrated by these YouTubers, and they left me winded and sweaty. For the cost of free, I can’t complain much. Most important, Yoga With Adriene succeeded in making me feel less dead inside.

What You Get When You Pay

To compare the free YouTube exercise videos with the paid experience, I subscribed to Peloton and Apple Fitness Plus on my Apple TV set-top box. I did workouts using both products for the last two months.

Peloton and Apple Fitness Plus addressed many of the problems plaguing the free exercise content.

For one, workouts were organized into categories by the type of workout, including yoga, strength training and core, and then by the difficulty or duration of the workout. It took little time to choose a workout.

In both Peloton and Apple Fitness Plus, video and audio quality were very clear, and the workouts were shot at various angles to get a good look at what the instructors were doing. The bonus of Fitness Plus was that my heart rate and calories burned were displayed on both my Apple Watch and the TV screen.

In short, paying those subscriptions provided convenience and polish, which led to a more pleasant workout. I concluded that Peloton’s videos were worth paying $13 a month. And $10 a month is reasonable for Apple Fitness Plus, but only if you already have an Apple Watch and iPhone.

Making a D.I.Y. Peloton

So what about exercise equipment like spin bikes? If you want the tech frills of a Peloton but don’t want to spend on the equipment, there were two main approaches.

To go the cheapest route, you can make use of a bicycle you already have. Here’s where home tinkerers can be especially crafty and resourceful.

Take Omar Sultan, a manager at the networking company Cisco. He modified his road bike with a few add-ons: a bike trainer, which secured the rear wheel and bike frame and costs roughly $100; a $40 Wahoo cadence sensor that tracked his energy output and speed and transmitted the data to a smartphone; and a heart rate monitor that strapped around his chest, such as the $90 Polar H10. Then he used a streaming device to follow Peloton classes on his TV.

“The D.I.Y. setup is 80 percent of the way there” to a Peloton, Mr. Sultan said.

The more expensive option was to buy an indoor exercise bike and use a tablet or phone to stream cycling classes via YouTube or the Peloton app, as Ms. Whitney did. The $700 IC7.9, for example, includes a cadence sensor and a holder for your tablet. You could then buy a heart rate monitor and a pair of $100 indoor cycling shoes that clip into the pedals.

But if you use your own bicycle or a modified spin bike and try Peloton’s app, you won’t be able to participate in the app’s so-called leader board, which shows a graphic of your progress compared with other Peloton users online.

With a D.I.Y. bike, it can also be difficult to figure out how to shift gears to simulate when the instructor is telling you to turn up the resistance — like when you are pretending to ride up a hill.

Nicole Odya, a nurse practitioner in Chicago who modified a high-end indoor bike, the Keiser M3i, said there were major upsides to the D.I.Y. route. Using her own iPad, she has the flexibility to choose whatever fitness apps she wants to use, such as Zwift and mPaceLine. It also gave her the freedom to customize her bike, so she swapped out the stock pedals for better ones.

“I didn’t want to be locked into their platform,” she said of Peloton.