Contrary to popular belief, carrying a high training load (volume + intensity) is not the biggest reason why people get injured. After coaching all levels of endurance athletes for more than 16 years, I am convinced that the number one cause of injury is inconsistency.
Those who train the most and the hardest are often the most resilient; whereas those who are inconsistent with their training are often the most injury prone. The body thrives on consistency. It thrives on a systematic gradual progression in training load. It thrives on patterns in your training be it running 7 days per week or 3 days. It thrives on knowing that you have hard days on the same day each week and easy days on others. The body gets use to these patterns, and it depends on it. Ultimately, the body rewards you for this.
If you find yourself to be injury prone, look first to establishing consistency in your training. Did you jump your mileage or intensity too quickly, are you just doing what you feel like with your speed work, and are you inconsistent in your volume week-to-week? If so, make changes here first. You will find that you will be able to handle greater training loads than you can image if that training load is consistent.
Do not compromise consistency for anything.
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