Concurrent Training in Primarily Power Athletes: Proceed with Caution

Author: Jared Defriend

During my younger high school, there was nothing I loved to do more than run for exercise. I think I ran almost every day during the week with my dog, and on the weekends, I would try to go on longer runs. However, there is an important piece I am missing to this story. I
played football, and not only did I play football, but I was also a lineman. I thought I could be the best endurance athlete ever, while still be a big, strong, defensive lineman. Little did I know I was destroying my potential, as the copious amounts of running I performed inhibited my ability to make gains on the field and in the weight room. Therefore, now I know that intense endurance training and power athletes, such as football players, just do not mix. For maximum results, power
athletes should stick with strong and powerful training, leaving the endurance stuff for who it was meant for: runners.

Who’s not to say that an extent of aerobic training could be beneficial for power athletes? By training aerobically for a period of time, a power athlete is able to increase their VO2 max, lactate threshold, and overall work capacity. By increasing these three things, simply put, an athlete
will be able to perform “work” for longer periods of time, as lactate will take longer to accumulate, which is the compound that makes our muscles fatigue as we workout for an extended period of time. In other words, there is no point training for strength and power if an athlete accumulates too much lactate, develops too much fatigue, and can no longer move powerfully and explosively either in the weight room, on the court, in the field, etc. Building an aerobic base is not just
beneficial to the development of a power athlete, it’s crucial.

However, at some point the madness must stop, or at least should be limited especially as a season of competition draws near. Researchers Ronnestad and colleagues performed a study that measured the effects of either concurrent strength training or strength training only in two groups

of cyclists. At the end of a 21 week training period of either concurrent strength plus endurance training or strength training only, the two groups performed a series of tests, such as a 1 rep max of a squat, a squat jump height test, and a measurement of the cross sectional area of the muscle was taken. The results? The groups that only performed strength training over the course of the 21 week period displayed a greater increase in thigh cross sectional muscle area, as well as better
performances in the 1RM squat and squat jump test compared to the concurrent training group (Ronnestad et al., 2012). This comes as no surprise, when we break down the physiological components that cause these endurance or strength adaptations to occur.

To cut to the chase, training for strength and power creates a specific biological pathway for neuromuscular adaptations, and training for endurance creates its own neuromuscular adaptations as well. The key biochemical agents to remember here are mTOR and PGC1-alpha.
When resistance (weight/strength) training occurs, cell signals from muscle stretching signal the biochemical agent mTOR to synthesize proteins. This protein synthesis, along with a calorie rich diet of course, is going to cause hypertrophy or growth of type II muscle fibers. These are the defined muscle fibers we notice as Olympic sprinters race down the track, or as NFL defensive lineman squeeze the life out of an opposing quarterback for a sack. As cross-sectional area of these
muscles increase, strength and power are soon to follow. However, as previously mentioned, endurance training creates an adaptation of its own, and it does not favor strength. When endurance training occurs, the biochemical agent known as PGC-alpha is signaled to synthesize more mitochondria, and to cause a shift from fast twitching type II muscle fibers, to slow twitching type 1 fibers. The latter of the previous statement is the scary part, as an increase in type I fibers could
cause detrimental effects to the strength and size power athletes and coaches strive for. Not only does this shift occur, but the signal for mTOR is blocked entirely for an extended period of time.

However, elite athletes will always train concurrently, such as elite Crossfit athletes, and still will turn out pretty darn strong. How do they do this? Turns out, the mTOR biochemical signal is activated for up to 24 hours after, and mTOR blockage by PGC1-alpha is only activated up to 3 hours. Therefore, if someone looking maximizing their strength or power still wanted to maintain an outstanding aerobic base, by endurance training the day following a strength session with a limit
to only a couple of times a week, they should be just fine. But there is one caveat to concurrent strength and endurance training as well. Hakkinen and colleagues performed a similar study with similar results to the study previously mentioned, with a group of strength only athletes, as well as a group of concurrent athletes. The results of this study were quite similar. All groups made gains in strength and cross-sectional muscle area, but the strength only groups had better results.
Furthermore, the strength only group exhibited a change in peak rate of force development, whereas the concurrent group showed no change in this (Hakkinen et. al). Rate of force development is what causes the snappy change of direction movements and explosive power we see on a football field. The time it takes for a person to exert force, it is truly what makes a power athlete, a power athlete. Because concurrent training can have any adverse effect on this, I would
vote to stay away from it as competition approaches especially. By doing this, power athletes should soar to new heights in their vertical jump, smoke opponents off the line in a friendly 40 yd dash, and witness the snappiest power cleans imaginable (with proper technique training of course).

Training for strength and power generates specific biological adaptations geared towards strength and power, and training for endurance generates specific biological adaptations geared towards endurance, simply put. If you are determined to run blazingly fast, as well as run forever, and know exactly what it takes to get there as well as have a nice stash of performance enhancing drugs (just kidding), then it is possible to have it all and I encourage everyone to wants it to go for it. I am not aiming to limit anyone’s potential, all I am asking is that the next time any power athletes reading this are encouraged to go on a run, they proceed with caution.

Rønnestad, Bent R., et al. “High Volume of Endurance Training Impairs Adaptations to 12 Weeks of Strength Training in Well-Trained Endurance Athletes.” European Journal of Applied Physiology, vol. 112, no. 4, 2011, pp. 1457–1466., doi:10.1007/s00421-011-2112-z.

Häkkinen, K., et al. “Neuromuscular Adaptations during Concurrent Strength and Endurance Training versus Strength Training.” European Journal of Applied Physiology, vol. 89, no. 1, 2003, pp. 42–52., doi:10.1007/s00421-002-0751-9.