Have you tackled hills yet? Lots of walkers stick to the track, mall, or other level areas. Nothing wrong with that. But, you'll get more bang for your buck - more aerobic and endurance benefits if you walk some hills. These hills needn't be like THE HILL that I've written about earlier. There are strategies for any incline. Try some of these if you want to take to the hills.
Get warmed up first on the level surfaces. Walk at a pace where you can talk comfortably without getting out of breath. Start with a slight incline and one that's not too long.
To walk from my house the approximately 1/2 mile to the park I frequent, I must toddle uphill about 2/3 of the way. It's not a steep incline. But, it's steady. Driving it, you'd never think that it's much of an incline at all. Different when you're on foot. This is the first stretch of my walk, if I head in that direction, so I'm not warmed up when I start out. In fact, to get out of my street to walk anywhere else, I must walk past 6 houses, each on a 1/2 acre lot. That's not so far, but can be a challenge if you're not used to it.
Further, although the track at the park looks flat, it's not. There's a steady incline on it's northern 'leg'. You notice that when it's 98 degrees outside and you're on you're third mile!! Otherwise it's not of much notice.
If you're new to walking hills, keep it simple. Once you're warmed up, head for the hill and take it slow. Also, be sure you don't lean too far forward to compensate for the incline. I find myself doing this too often. It's a mistake. It feels easier at first - but over time, you realize that it's easier to remain upright and use your thigh muscles to get up that hill. Kinda like climbing stairs only you don't have to step quite so high.
If you find yourself getting winded - just slow down and take it easy. Stop talking and concentrate on your breathing. One way to get your breath back easily is to practice 'pursed mouth breathing'. This is an old trick used by asthmatics who have impaired oxygen exchange. The idea is to blow out kinda like you're blowing up a balloon - only not so hard. That expels the spent air from your lungs and allows more oxygen in. This is sound science. Just try it. You'll find your 'second wind' comes much more easily.
Continue walking if you can. To obtain the best aerobic advantage, you shouldn't stop and stand still once you've raised your heart rate. Just slow down. Disclaimer - IF YOU HAVE CHEST PAIN OR FEEL FAINT, CALL FOR HELP IMMEDIATELY. I'm not a doctor. Trust your own judgment.
Once you can comfortably climb a slight incline while talking, go for a longer incline and then a steeper incline. If you feel stranded on a steep incline, turn around and walk back down or zig zag up to diminish the steepness. You have seen trails up the side of a mountain - they always zig zag or go around the mountain since going straight up is just too steep for foot or auto traffic.
Of course, you can receive these same aerobic benefits on a treadmill by increasing the slope. Most treadmills have a way to select the incline. Build up to a fairly steep incline over time. It takes work. It won't come easily to many of us. That's why we start slow.
But, keep at it. Even if you only increase the incline a tiny bit each week, if you persist, you'll be climbing mountains before you know it. The gym has the advantage of climate control - not something available to those of us who trudge around outside. But, however you get to that 'hill', you'll appreciate the way you feel once you've climbed it.
Now that you've climbed up, I have some ideas for descending from the summit. Stay tuned.
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Remember my 100% GUARANTEE. Should you decide to stop walking and resume your old habits, I personally guarantee that you'll get back 100% of your former life - your pain, your lifestyle, your attitude.