To quote Dr. Daniels himself, “No one has all the answers to what works best for any individual runner. Plus, everyone reacts differently to each type of training” (Daniels, 2005; pg 67).  This has been a prevalent theme in the discussion this week on aerobic training volume, as well as a common conclusion from research.  Each athlete may benefit from different volumes of endurance training. Some athletes optimize their abilities through relatively high volumes of training, whereas others are overstressed by that same volume. For example, while many successful marathon runners exceed 100-miles of running in a given week of training, there are others who are comfortable training at closer to 40-miles per week (and manage to qualify for the Boston marathon on such low mileage!) (Flatow, 2013). Clearly, one key to prescribing the optimal dosage of training volume, is to gather frequent feedback from the athlete about how their training makes them feel. Teaching runners to be "tuned-in" to their body’s natural feedback, and to obey the signals their body is sending, is important to the longevity of their fitness gains.

Nearly all endurance athletes will gain fitness by adding more volume to their training, to a point, however. The principle of diminishing returns comes into play here; as adding more volume results in smaller increments of adaptation as the volume increases. Additionally, as an athlete approaches their physiological limits, the likelihood of a setback due to physical and/or emotional over-stress increases. Therefore, it is essential to carefully consider the incoming bodily signals the athlete is receiving and the outgoing signals the athlete is sending to their coach, in order to prevent increases in training volume from over-stressing the athlete’s body and mind, especially considering the decreased “bang-for-the-buck” they get from increasing their volume (Daniels, 2005).  At some point, increasing volume is detrimental for athletes, and that point is unique to each athlete.

In order to avoid increasing an athlete’s training volume beyond this critical point, It has been recommended that athletes not increase their weekly mileage until they have safely completed three weeks at that particular volume without incident. If the athlete is comfortable increasing their training volume, the volume can be increased by one mile for each training session the athlete has completed during the course of the week (Daniels, 2005). This ensures that the increase in training volume is great enough to elicit a response, in accordance with the principle of stress response, but not so great that the athlete is placed under excessive stress that may accelerate their likelihood of an injury causing a setback.

For coaches, asking athletes questions about how their training is making them feel both physically and emotionally, and then taking that feedback into careful consideration when making decisions about how to progress is one key to maintaining the athlete’s overall health, fitness progress, and interest in the sport.


Daniels, J. T. (2005). Daniels' running formula (2nd ed.). Champaign, IL: Human Kinetics.

Flatow, K. (2013). In defense of low mileage: Boston on less than 40 miles per week. Marathon & Beyond, 17(2), 76-87.

Training Volume: Following Guiding Principles and Athlete Feedback