Building endurance requires patience and smart planning. Here is how to balance volume, pace, and recovery to avoid injuries like tendon issues.
Anyone training for a marathon usually wants two things at once: to get faster and to conquer the distance without hitting the wall. Yet the line between effective performance gains and physical overload is thin. How severe the consequences can be when warning signs are ignored was shown at the Berlin-Marathon, according to Runner’s World: Tigst Assefa already felt pain in her right Achilles tendon at kilometre 31, yet kept running until the tendon ruptured at around kilometre 40. She covered the final hundreds of metres limping solely on her heel and had to undergo surgery in München the following morning. To prevent such severe damage or typical overuse issues like shin splints, well-thought-out training management is essential.
A common mistake in endurance training is packing almost the entire workload into a single, overly fast long run. Coaches emphasise in reports by Runner’s World that the long run should account for a maximum of 25 to 30 percent of the total weekly running volume. If your long run covers 16 kilometres (10 miles), for example, your total weekly distance should sit at just under 48 kilometres (30 miles), spread across several sessions. This is the only way to build the necessary stroke volume of the heart and adapt to time on feet without overloading the musculoskeletal system at specific points.
For the many base sessions, the rule is: pace must remain controlled and low. According to experts like physiologist Trevor Connor and cardiologist Tamanna Singh, aerobic base training should take place in Zone 2. Blanket calculations like “220 minus age” are inaccurate and often deviate by up to 40 beats. For more reliable values, testing under hard, all-out effort is recommended, such as at the end of a 3 to 5-kilometre race, ideally using a chest or arm strap. If you still struggle to rein in your pace during easy steady runs, reducing speed is the key to better long runs. The Run-Walk method by Jeff Galloway, established since the 1970s, also uses targeted 30-second walking breaks to support recovery throughout the distance without permanently tanking overall pace.
Performance gains do not occur during the workout, but in the days that follow. As sports scientist Laura Norris explains, the body requires roughly seven to ten days—sometimes up to 14 days—after a hard training session to fully absorb the applied stimulus. Noticeable improvements in race pace and performance only appear in most runners after eight to twelve weeks of consistent training. Muscles, the cardiovascular system, and neuromuscular coordination adapt at different rates.
If recovery falls by the wayside—for instance, through a lack of sleep, insufficient carbohydrates and proteins, or the absence of genuine deload days—this adaptation window lengthens or fails to occur entirely. Tapering phases before a race last at least one to two weeks for this exact reason, often even longer for marathons, ensuring the body arrives at the start line having fully processed all training stimuli.
To maintain the balance between building fitness and staying healthy, you should anchor the following principles in your training plan:
Your takeaway: Keep your long runs slow, cap them at a maximum of 30 percent of your weekly volume, and respond immediately to pain signals before tendons become overloaded.
This article was generated automatically with AI from the sources listed above and has not been editorially reviewed.