Gradual load progression

The short answer

Increase one thing at a time and not by much. The familiar "10 percent a week" rule is a rule of thumb, not a proven limit: in a trial with novice runners, a plan built on it did not reduce injuries. What the evidence points to more clearly is single big jumps. In a study of over 5,000 runners, a run more than 10 percent longer than the longest of the previous 30 days was linked to more overuse injuries. Take an easier week every third or fourth week, and when you add speed work, hold mileage steady for a few weeks.

The body adapts to load over weeks, not days. The training that makes you fitter is the training you can repeat consistently.

The three levers

You can make running harder by going longer, going faster, or going more often. Changing all three at once is the most common recipe for trouble.

Pick one lever per week. If your long run grows, keep intensity easy. If you add intervals, keep the rest of the week steady.

Volume

Total time or distance per week.

Intensity

How hard the hard sessions are.

Frequency

How many days you run.

Easy weeks are part of the plan

Every third or fourth week, reduce volume by 20 to 30 percent while keeping the routine. This is not a rest week; it is the week where adaptation catches up with the work.

Runners who skip easy weeks often feel fine for a month and then lose two. The pattern is common enough to plan for.

If you are unsure whether this week should be harder, make it easier. You will rarely regret it.

Warning signs of too much

Persistent soreness that does not ease with easy days, pain that worsens as you run, or a change in your stride are all reasons to reduce load and get advice. Discomfort that lingers beyond a few days deserves attention.

Sleep, stress and nutrition all lower the load you can absorb. A week that was easy last month can be too much this month if life has changed.

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