Long runs can consume entire weekends, particularly during marathon training. Runners with limited time may still achieve the same fitness benefits without sacrificing their schedules.
Some coaches suggest splitting the miles across two shorter runs on back-to-back days. This approach maintains the physiological effects of a single long effort while accommodating a busier routine.
How bunched long runs work
The method involves dividing the distance into two parts. The second run begins 12 to 15 hours after the first—such as eight miles on Saturday evening and 10 miles the following morning. The timing is intentional.
Brian Rosetti, a Philadelphia-based run coach and founder of V.O2, explained that glycogen stores don’t fully replenish within that window. Since glycogen typically takes 20 to 24 hours to restore, the 15-hour gap keeps the body in a depleted state, simulating the fatigue of a continuous effort.
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Ultrarunners have long used similar strategies, often capping training runs at a third of their race distance to prevent form breakdown. Rosetti said running for extended periods can degrade mechanics, increasing landing impact and stress on joints and muscles. Stopping before that occurs may lower injury risk, provided mileage increases gradually and strength training remains part of the plan.
When to use the method
Bunched long runs shouldn’t replace every long run in a training cycle. Coaches recommend limiting them to four or fewer in a program, spaced three to four weeks apart. They’re particularly helpful for runners prone to injury or new to longer distances.
Janet Hamilton, exercise physiologist, RRCA-certified run coach, and owner of Running Strong, shared the example of a parent unable to secure childcare for a four-hour block but able to find two shorter windows. That flexibility allows completing the miles in a split format rather than all at once.
However, the method has limitations. Rosetti stressed that runners should still complete at least one continuous long run, such as an 18- or 20-miler, before race day. The body must adapt to the full distance, and bunched runs can’t fully replicate that experience.
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Making it work for you
Timing is key. Most runners prefer a Saturday evening run followed by a Sunday morning effort, often taking Monday as a rest day. Alternatively, both runs can occur on the same day—early morning and evening—if that suits the schedule better.
Pace also matters. Both runs should remain at the usual easy long-run pace, without incorporating tempo efforts. Rosetti advised focusing on cadence to avoid starting too fast. Counting steps can help maintain the right pace for both sessions.
After the second run, expect soreness similar to a continuous effort. Delayed-onset muscle soreness (DOMS) usually takes longer than 15 hours to develop, so it won’t appear during the second run, but recovery afterward will feel comparable.
For those struggling to fit long runs into their schedules, this method provides a practical solution. While it won’t replace the need for a full-distance effort before race day, it can help when life interferes. Runners looking for comfortable gear during these sessions may find options that support their training needs.
