When the weather outside is frightful, the treadmill is so delightful. It's also bulky and expensive! Doing cardio during winter is going to be a challenge, particularly during COVID. Gyms may close down again, depending on the spread of the disease. You may not want to enter a gym regardless.
That means you have limited space, likely a limited budget, and limited options. Here's a little list of low-impact, compact and affordable cardio machines to get you through winter:
Mini Stair Stepper
The mini stair stepper isn't as effective as using a regular stair stepping machine. This model is sold on amazon for $75. This version has handles, so you'll have something to hold onto while you workout. There are also cheaper versions without handles, but they can be hard to balance on.
This product is a cheaper replacement for the Versa Climber. It's very low impact and challenging, similar to a stair climbing workout. There is some reaching and stretching incorporate in the movement. This model costs $400, but there's a cheaper model that costs $200.
While it's more expensive, the row ergometer is a very joint-friendly and low-impact machine. The movement incorporates lower and upper body, and the machines easily fold up and store vertically, making them ideal for an apartment.
This bike is a cheaper alternative to Peloton, if you're looking for a bike. Cycling workouts are heavily focused on the legs (particularly the quads) which is why a climber or row ergometer is probably a better workout. However, if you like the bike better, this product is a good choice. It costs $840
Upper Body Ergometer
The safest and most portable form of cardio is arguably the upper body ergometer. It's essentially just a bike you pedal with your hands. While it's cheap and very low-impact, the exercise itself might not be strenuous enough to have a big impact on your fitness level. The arm muscles engaged in the exercise are small relative to the amount of muscle engaged in a stair stepper or bike. However, the upper body ergometer is far better than doing nothing (and it fits conveniently on your desk).
While treadmills are for the most part large and expensive, this product gets a special mention. If you insist on buying a treadmill, this should be on your list. Its fairly cheap ($1,340) and it folds up so there's not a huge waste of space. Give it a shot if you insist on running/walking this winter.