The 21-day cardio challenge is a great way to jumpstart your fitness journey. The challenge is simple: for 21 days, you commit to doing cardio frequently on a simple yet effective scheme. This can be any type of cardio activity that you enjoy, from running to biking to swimming (we’ll share our top 5 activities, so stay tuned!) The key is to find something that you will stick with for the long haul. The 21-day timeframe is just enough time to form a habit, so if you can make it through the challenge, you’ll be well on your way to a healthier lifestyle. And who knows, you might even find that you enjoy the cardio workout more than you thought you would! So why not give the 21-day cardio challenge a try? Let’s get to it by first covering some fundamental