Concurrent Aerobic and Strength Training Moritz Schumann 2019

I’ve not read this book. But it is available in PDF on the web. I have started reading. So far I think it does a good job of covering the history of the concurrent strength and endurance training arguments. The conflict is best understood in terms of the signaling pathways that induce a cascade of adaptations at the genetic level. In short: the aerobic adaptation path is called AMPk (adenosine mono phosphate kinase) that is triggered by an aerobic stimulus and results in a host of adaptations that improve aerobic capacity and power. mTOR is the strength adaptation path that results in gains in strength usually through hypertrophy or hyperplasia. These two paths conflict with one another to some degree. the AMPK pathway tends to down regulate the mTOR path. You have seen this in action. Body builders don’t run because it negatively impacts the muscle mass gains they seek. Heavily muscled folks who take up running, lose muscle mass even if they keep strength training. The mTOR path does not down regulate the AMPk path so much. Here is an interesting quite from the book that overlooks a critical factor and is why I still contend that coaches lead the scientists.

Moreover, “The evidence against well-trained endurance athletes incorporating resistance training into their normal workouts to improve their endurance performance appears to be strong” ([28], pp. 136). While the early studies of Hickson and others were acknowledged, it was further suggested that “[…] for highly-trained athletes who are already capable of generating high power outputs in their chosen discipline, further improvements in strength are a less important factor in enhanced endurance performance. At the highest level of competition, increases in strength and power per se are not as critical to successful performance as the development of correct technique. The bottom line is that modern training studies do not support the use of resistance training programs for improving the performance of highly-trained athletes” ([28], pp. 137–138).

The kind of strength training usually used int these studies is conventional general strength lifts like dead lift or squats. Developing higher levels of general strength in weak people will improve their endurance performance. But at some point that general strength stops transferring well to performance in the well trained. The well trained need to be concentrating on sport specific strength and power training to see performance gains. Coaches know that increasing sport specific power leads to increased economy (longer stride length) and hence improved performance. Verkhoshansky showed this in the 50s and several other studies have been done confirming this. Another quite from the book:

Throughout the subsequent years, the effects of strength training for aerobic per- formance were of minor research interest. However, in 1999 studies by Paavolainen et al. [26] and Hoff et al. [27] provided evidence for improved exercise economy and consequently overall endurance performance in cross-country skiers. Similarly to the early study by Hickson, also these studies showed that performance improve- ments occurred independent of improvements in VO2max and were much rather related to changes in neuromuscular characteristics. This is because in the study by Paavolainen et al. the improvements in 5 km running time were actually associated with a shorter ground contact times and, thus, a more economic running pattern.

I recommend the book.
Scott