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Hey guys, welcome back. Today we are going to be talking about the concept of concurrent training. For years, I’ve been hearing powerlifters bashing on endurance training and cardiovascular exercise, claiming that even the lightest of jogs will instantly wipe out muscle mass and strength gains.
For the majority of lifters, that is not going to be the case. In fact, today I want to dive into some science and show you why you should stop making excuses and get your damn heart rate up for longer than a minute.
In this video, we will be addressing the following questions:
First, what is concurrent training?
The term “concurrent training” refers to the combination of lifting weights and performing aerobic exercise within a single training program. CrossFit is the perfect example of this, where athletes can expect to perform cyclical, repetitive tasks like running and rowing as well as heavy lifting within the same training session. Collegiate and professional athletes also perform a combination of these tasks in order to facilitate high levels of both strength and stamina on the field or court.
What is the interference effect?
The notion of the “interference effect” of concurrent training gained attention in the 1980s when researchers started to notice that athletes who participated in both styles of training experienced a certain level of attenuation in their strength and power gains (Hickson, 1980). Since then, exercise scientists have speculated on what factors specifically contributed to the interference effect. Today, we still don’t have a crystal clear answer to that question, but it is suspected to be related to differences in muscle fiber type recruitment, energy system utilization, and/or a propensity toward overtraining or overreaching when both resistance and aerobic training methods are incorporated into a single training program.
Somehow, the idea of the interference effect permeated into the fitness community and instilled fear in those who valued being strong, convincing them that participating in even the slightest bit of cardiovascular exercise would instantly kill all of their gains. Precious, hard-earned muscle would waste away, transforming your physique into that of a marathon runner.
Although that is definitely an exaggeration, decreased neuromuscular performance has been observed in more recent studies on concurrent training. However, this attenuation was only significant in the realm of lower body power production. In fact, concurrent training did not appear to have a significantly detrimental effect on lower body hypertrophy or strength (Wilson et al, 2012).
But we can’t just take this data and run, so to speak. There are so many variables that may contribute to an interference effect, including aerobic exercise intensity, frequency, duration, and modality. Your individual training history and level of experience can also play a role.
You may be asking yourself, “Stef, if there is even the slightest risk of me losing my gains in one way or another, why would I even bother giving this concurrent training shtick a shot?”
What so many people fail to recognize is that aerobic exercise has a host of benefits, many of which can positively affect your preferred anaerobic style of training; that is, lifting heavy things and putting them down.
How will concurrent training make me a better strength athlete?
Who should do concurrent training?
Novice and beginner athletes in particular appear to be the perfect specimens for concurrent training. Compared to highly trained athletes, untrained athletes’ internal machinery is more sensitive to exercise stimuli of all kinds, as these stimuli are likely received as large disruptions to the body’s homeostasis (i.e. a person’s cellular comfort zone) compared to an athlete whose structures are used to regular training. This results in beginner athletes enjoying significantly steeper curves in terms of training-induced adaptations with little interference effect.
Including an appropriate amount of aerobic exercise is also likely to benefit the average strength athlete who may compete recreationally in powerlifting, Olympic weightlifting, StrongMan, and other strength sports. However, when sport specialization comes into play, we start to travel down the narrow end of the funnel of movement priorities, meaning that extraneous exercises that do not closely relate to the goal are pruned away.
For example, a highly competitive powerlifter who has an international competition in 6 weeks is better off training the 3 main lifts rather than trying to PR her 5k time or doing long metcons 3 times per week. That seems logical enough, but it’s important to point out that we aren’t suggesting specialized athletes risk an interference effect during crucial training phases.
In summary, unless you are a competitive athlete preparing for a meet in the next 6-12 weeks, you’ll probably benefit from a little bit of cardio-- especially if you are a beginner or novice lifter.
How can I avoid an interference effect?
The fact is that all endurance exercise is not created equal. Intensity, frequency, duration, and modality all appear to elicit the interference effect to a different extent. Use the following information to manipulate these variables and make your concurrent training work for you rather than against you.
First, let’s talk about Aerobic Exercise Intensity.
Unfortunately, there is conflicting evidence that both supports and refutes the notion that higher aerobic exercise intensity elicits a greater interference effect.
When in doubt, always come back to your own training priorities and goals. A concurrent training program that emphasizes high intensity aerobic training will induce greater aerobic improvements, while a program that emphasizes high intensity resistance training will induce greater neuromuscular improvements. Performing both exercise styles at rigorous, high intensities requires a delicate balance of programming and carries a higher risk of overtraining if not properly implemented, resulting in attenuations in adaptations across the board.
One programming option that athletes and coaches should explore is a polarized distribution of exercise intensity. This method prescribes days of higher intensity training and days of lower intensity separately and has been shown to elicit increases in maximum strength and aerobic capacity while preserving certain markers of lower body power. If you’re looking for cardiovascular gains without the cost of your power production, programming with a polarized intensity distribution may be useful.
Aerobic Exercise Modality
There are many cardiovascular exercise modalities, including running, cycling, swimming, rowing, power walking, and jazzercise, just to name a few. Studies have suggested that different types of aerobic exercise may carry differing risks of an interference effect when included in a concurrent training program.
For example, a meta-anaysis (Wilson et al, 2012) showed that when strength training was performed concurrently with running, significant decreases in lower body hypertrophy and strength were observed compared to the group who participated in strength training only. On the other hand, the group that combined strength training concurrently with cycling did not see a significant decrease in the hypertrophy and strength variables. Kind of makes you want to hop back on the assault bike, huh?
Not so fast. The opposite effect was seen in a more recent study comparing concurrent high-intensity interval training (HIIT) plus resistance training to resistance training alone; there was a stronger negative correlation between cycling HIIT plus resistance training and lower body strength compared to running plus resistance training (Sabag et al, 2018). But who is to say that the cycling group wasn’t subjected to overtraining given the higher intensity nature of the intervention?
In the face of this conflicting evidence, it seems like we can’t make an infallible evidence-based decision on which modality of aerobic exercise to incorporate. Thus, any recommendation for endurance training modality should be tailored to the individual athlete based on his or her experience, strengths, weaknesses, and goals, followed by close monitoring of endurance training volume.
Aerobic Exercise Training Duration & Frequency
While there doesn’t seem to be a reliable verdict on intensity and modality, aerobic training duration and frequency dosing does seem to play a more consistent role in neuromuscular performance attenuation. For example, as training duration increases past 20-30 minutes per day, there appears to be an increasingly negative effect on muscle strength, hypertrophy, and power (Wilson et al, 20120).
This relationship between aerobic training volume and strength, hypertrophy, and power outcomes could be attributed to an increased likelihood of overtraining or overreaching, which would expectedly yield performance decrements in both aspects of training. This is known as the “chronic interference hypothesis,” suggesting that the decrements in strength, mass, and power are really a result of overtraining when training volumes begin to surpass an athlete’s ability to recover.
Some researchers also argue that the different types of exercise elicit competing physiological adaptations based on differences in muscle fiber types and energy system utilization. This hypothesis supports the idea that athletes could choose to participate in cardiovascular exercise that more closely resembles the characteristics of resistance training from an energy systems standpoint, such as sprint intervals, and/or from a movement pattern similarity standpoint, such as cycling or rowing.
That was a lot to take in, so here is the moral of the story:
I hope you guys liked this video and learned something that you can incorporate into your own training. The Hybrid Education team and I are always looking for ways to help you maximize your athletic potential, so please give this video a like and subscribe to my channel if you want to see more helpful, evidence-based content like this. Leave a comment below with any questions and we’ll try our best to get back to you.
Thanks for watching. Catch you in the next video!