There are three reasons to climb out of the saddle:
1. To pick up your cadence or apply power
2. To give your body a stretch
3. To slow down your cadence and heart rate
I see way too many beginners thinking that they always need to maintain too high of a cadence for their fitness and pedal stroke...and wear themselves out trying to 'spin'. Sometimes it's better to slow it down, use a bit higher gear and let your body weight help you achieve a rhythm that doesn't put your HR into the red zone.
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"Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey