Concurrent training, and the optimisation of training programming to maximise an individual’s response to both resistance and endurance training, is an often hotly debated in the fitness world. This can lead to polarising views and misunderstanding of the topic across the fitness sphere.
Common questions from trainees and coaches arise such as:
“Does doing cardio hurt my resistance training gains?”
“Should I do resistance training before or after endurance training?” “Can resistance training help my endurance training performance?”
“I’m a team sport athlete, how do I maintain my strength in-season?”
“What is the best way to structure my week if I play sport on the weekend?”
“I train a few times a week to stay fit and healthy, how do I implement concurrent training into my program to get the best benefits of resistance and endurance training?”
“What is the best type of endurance training to complement resistance training if I want to maximise resistance training adaptations?”

Over this series on concurrent training I will dive into the research, and my first-hand experience as a coach and athlete, to answer the most prominent questions facing clients, athletes and coaches on their quest for maximising progress in the gym and out on the track/road/field.
First, it is important to understand what concurrent training is and some of the factors which determine one’s adaptation to a concurrent training program.
The systematic integration of endurance (END) and resistance (RES) training within a training program is commonly referred to as concurrent training [1]. The primary aim of a concurrent training program is to simultaneously enhance both endurance and resistance training adaptations relative to your specific training goals. This training approach is utilised across general and athletic populations, as a means of improving general health and wellbeing, athletic performance and body composition [1-5]. It is also important to understand, long term physical adaptations to training are primarily driven by the accumulation of specific physiological responses to acute bouts of stress placed on the body during exercise (within a training session) over an extended period of time (weeks, months, years) [6].
Therefore, the importance of a well-structured and specific training program which takes into account your individual goals and macro, meso and microcycles is of paramount importance to achieving the desired outcomes.

Resistance and endurance training represent two distinct ends of the physiological adaptations to training spectrum [7]. Many training and athletic pursuits typically require a combination of the adaptations produced by the two modalities, in ratios sport & goal dependant, to be able to perform the required task at an appropriate level.

Before proceeding it is important, we have a clear understanding of Resistance and Endurance training.
What is Resistance Training?
Resistance training involves the use of bodyweight or external loading on the body to create sufficient stress on the neuromuscular system, muscle tissue, tendons and joints. This is undertaken to elicit a favourable muscular, hormonal, neural and metabolic response which will facilitate increased muscular power, strength and size and subsequently improve musculoskeletal performance over time [8].
What is Endurance Training?
Endurance training is primarily utilised to develop cardiovascular and cardiorespiratory function and improve metabolic pathways responsible for enhancing energy substrate usage during continuous and intermittent endurance exercise [9, 10].
Having an understanding of the above training modalities, suggests that the very nature of simultaneously integrating both endurance and resistance training into a single program may present a dilemma, as combining both may create an environment for divergent adaptations in some situations [11, 12].

The research on concurrent training can come across as quite conflicting, however it is important to understand how concurrent training research has evolved over time and the nuances of the subject matter when interpreting findings.
To give some further
background, research into the effects of concurrent training has primarily
focused on how concurrent training programs may affect resistance training
outcomes. Early research into this area performed by Robert Hickson in 1980 revealed
that combining cycling and high intensity resistance training over a period of
10 weeks resulted in less improvements in maximal strength compared to a group
performing resistance training by itself, Hickson termed this phenomenon “The
Interference Effect” [13].
Subsequent research over the last 40 years has sought to identify the
particulars of why this may occur and how to counteract the so-called
“Interference Effect” and others have challenged whether it actually exists at
all [14].
A Meta-Analysis (statistical analysis of all relevant studies) of all the available research on concurrent training was conducted by Wilson & Colleagues in 2012 [15]. The key findings were as follows:
– A slight reduction in resistance training adaptations of strength and lean body mass were observed when performed within a concurrent training program compared to resistance training performed by itself.
– Lower Body Muscular Power was significantly affected in concurrent training programs compared to resistance training by itself.

– Concurrent training with cycling showed less decreases in resistance training variables compared to running, although this was not statistically significant. Running showed a significant decrease in lower body strength and hypertrophy compared to the strength only group.

– Endurance training
adaptations improved to a greater extent with concurrent training vs endurance
training by itself.
– Greater decreases in body fat were observed when endurance activity achieved a high heart rate in training.

Now from this analysis it is important to understand, that the concurrent training programs were simultaneously developing resistance and endurance adaptations, whereas the individual resistance and endurance programs were only developing one quality at a time. What is important to take away is that when combining modalities, dependent on your goal you may have to accept a slightly slower rate of progress, particularly when it comes to resistance training adaptations, to also gain the benefit of improvements in your endurance training endeavours.
However, when structured appropriately within a training program, the two types of training stimulus can result in substantial improvements in both resistance training and endurance training outcomes. There are 2 broad categories of variables (Training Variables & External Variables) and several nuances within each which can influence how to design a concurrent training program, and ultimately determine the outcomes of said program for an individual:
Training Variables
– Specific training goal – resistance training or endurance training outcome
– Intensity of training (both resistance and endurance)
– Frequency of training
– Volume of training
– Ratio of Resistance to Endurance sessions throughout a week
– Periodisation of training structure throughout a week (Within Session / Same Day / Alternate Day)
– Phase of training (ie Pre Season vs In-Season or Low Volume vs High Volume)
– Endurance training modality selected
– Time course of tissue adaptation
External Variables
– Level of individuals training experience (Beginner/Intermediate/Advanced)
– Nutritional structure and periodisation during different phases and focus of concurrent training
– Recovery strategies
Consideration of the aforementioned variables, along with the respective impacts of each, is essential to understanding the finer details of concurrent training and its outcomes. In order to achieve the best results, there are a number of strategies around program design and variable manipulation which can be implemented, therefore minimising the interference effect. These strategies will be discussed in coming articles, stay tuned for more of the deep dive!
Written by Performance Coach James Ballantyne
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2. Garber, C.E., et al., Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise. Medicine & Science in Sports & Exercise, 2011. 43(7): p. 1334-1359.
3. Taipale, R.S. and K. Hakkinen, Acute hormonal and force responses to combined strength and endurance loadings in men and women: the “order effect”. PLoS One, 2013. 8(2): p. e55051.
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7. Nader, G.A., Concurrent strength and endurance training: from molecules to man. Med Sci Sports Exerc, 2006. 38(11): p. 1965-70.
8. Bob Murray, W.L.K., Practical guide to exercise physiology. 2016: Human Kinetics. 208.
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10. Saltin, B., B. Essén, and P.K. Pedersen, Intermittent exercise: its physiology and some practical applications, in Advances in exercise physiology. 1976, Karger Publishers. p. 23-51.
11. Baar, K., Training for endurance and strength: lessons from cell signaling. Medicine and science in sports and exercise, 2006. 38(11): p. 1939.
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14. Murach, K.A. and J.R. Bagley, Skeletal Muscle Hypertrophy with Concurrent Exercise Training: Contrary Evidence for an Interference Effect. Sports Med, 2016.
15. Wilson, J.M., et al., Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. J Strength Cond Res, 2012. 26(8): p. 2293-307.