I am determined to keep up with these walks. There is no replacement for an outdoor walk. I walked today despite some drizzles. It's just so much healthier to exercise outdoors. In a gym, you breathe in the air you or someone else just breathed out. On a treadmill, you're taking the same steps repeatedly, but when you walk outside, you have to adjust to different terrain. Walking creates a pendulum motion with your body, this enables your endocrine system to function. Without that motion, there is no pump (like your circulatory system has with your heart) to get your thyroid and adrenals going.