In order to strengthen your muscles effectively, you've got to keep them guessing. The easiest way to do that is to mix up the order you work your muscles. If you're used to starting with bicep curls and triceps dips to work your arms, start with squats and lunges instead, and work your arms last. Tiring out your muscles in a different order will not only be more challenging, but varying your routine will also prevent boredom.
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