Exercise can be a difficult, time-consuming activity to squeeze into your day. Finding the type of exercise that you'll stick with can also be expensive: yoga classes, gym memberships, home equipment, Zumba classes, the list goes on and on. However, there are plenty ways to exercise at home for free or requiring only minimal investment. So if you're looking to fit some more activity into your routine without dropping a ton of cash, check out some of these ideas:

1. Running

Running requires only a decent pair of sneakers, and possibly your phone or an ipod for musical accompaniment. If you can find a nice trail on a bike path or even throughout your city, you'll have plenty to look at, and it's a great way to clear the mind. Best of all, it's an activity that can be done at the start of your day or the end, whenever you have time.

2. Pilates

Pilates is training yourself to lift the weight of your own body, and it's way harder than you think. Since the focus is being able to lift the body, no extra equipment is truly required. You can find plenty of workouts and moves online in health forums and other places, like Pinterest.

3. Yoga

You don't need a trendy studio and a super fancy mat to practice. All you need is a firm non-slip surface (it does help to have a mat of some sort, but it doesn't have to be fancy), comfy clothes, and some knowledge of the basics. You can find lots of tools to help you build a home practice, such as guides for flows, different poses, breathing techniques, and their significance.

4. Home Workouts/Online Workouts

There's a multitude of home workout DVDs, online circuits, and YouTube workout videos that you can easily incorporate into your day and build your own unique routines. You can find all sorts of workouts, and a little bit of searching is bound to help you find the routine that's right for you. One of my personal favorites is Blogilates on YouTube, which has workouts of every imaginable part for every ability level all in one place.

5. Boxing Pads

You might have an old punching bag in your basement, or maybe some old hand pads in the garage. Kickboxing and bag work routines are an excellent way to get your cardio going. Plus, these are really fun workouts to do with a friend!

6. Jumprope

Likewise, it's probably you might have an old jumprope lying around somewhere. Jumping rope is another great yet simple way to get your cardio up.

7. Biking

Riding your bike can be great for exercise and an effective means of transportation. Instead of taking the car for short distances, try seeing if you can bike it. Over time, you can increase your distance as your stamina increases. Biking also forces you to take in and appreciate the scenery around you, and like running, it can be a great way to clear your mind and de-stress.