Fitness Experience > Strength and Conditioning Blog  > Concurrent training and interference effect

Concurrent training and interference effect

Concurrent Training and Interference Effect- How to maximise results in both strength and endurance performance.

Training strength and endurance together? Read this to ensure you’re not holding yourself back!

I’ve discussed this topic with some great coaches in the past, and clearly their views are shaped by the context they work in… they work in that context, and although the approaches may have been different, all did a great job of managing the situation they were in. But I remember my first insight into this topic- about 12 years ago, being told in a local gym that you should never train strength and endurance together in a programme, never mind the same session! From then on, this topic has always been of interest to me- So, here’s a quick and simple summary of the right way to approach concurrent training to minimise interference effect.

What does it mean!?

“Concurrent training” simply means training both strength and endurance qualities within the same training programme (not necessarily during the same session). The “interference effect” is how much the combination of strength and endurance training reduces the adaptations to the training, compared with one modality alone. Now, before I start, if you are a world class athlete, this information will not be enough for you, and you will need to be looking in more individual detail at how to get the most out of your training. But you already know that. If you’re at a basic level with your training, without much experience in either strength or endurance training, or if you’re doing ok but limited for time (can only train 3 hours per week in one hour sessions, for example), then don’t worry about this either. Getting something done for health, cardio fitness, strength and hypertrophy should be included together at some point for you. If you’re in that middle ground, train ok, have a reasonable amount of time to dedicate to training, and want to make sure you get the most out of your hard work, then this is for you. Stick with it through the more complex part of the article, and it will put together some of the key factors influencing your training or coaching.


So, what causes the interference effect?

This article will focus on two key considerations, signalling pathways for adaptation to training, and acute fatigue/ energy depletion. (Stick with me for this bit- it may seem complex but we can’t pretend it doesn’t exist).


Signalling pathways and Interference.

For those looking for an in-depth review of this, look at the research directly. I’ve included some suggested reading at the end of this article that I believe will be a great start. This article is intended to give those with less of a scientific/ research background an insight into some of the factors that we need to consider to optimise the results.

When we train for strength/ hypertrophy (the “gym” work), we increase the activity of molecular signalling pathways which promote protein synthesis (and therefore strength/ muscle development). In particular, the mammalian target of rapamycin (mTOR) pathway is considered as a key pathway for developing these qualities.

When we train for endurance (running, cycling, etc), different signalling pathways are activated to enhance aerobic function. Adenosine monophosphaste-activated kinase (AMPK) is one particular pathway which is often considered when looking at the interference effect.

The Problem is that AMPK inhibits mTOR, and therefor supresses the strength training induced protein synthesis. See, that wasn’t too bad.


Acute Fatigue/ Energy Depletion.  

The second key consideration when considering interference effect is acute fatigue and energy depletion. This relates directly to how we programme the training, how well we recover, and how effectively we carry out the sessions. Simply put, if we are too tired to carry out a session of high enough quality to create the desired training stimulus (eg, too sore to lift heavy enough, or run fast enough), we will not get the desired training effect! Similarly, if we are energy depleted, and can’t handle the training session for the required volume/ intensity, we again will fail to create the right stimulus, and again fail to reach the desired training effect. FATIGUE ITSELF DOES NOT CREATE THE STIMULUS TO IMPROVE! All training has a cost, but not all has the desired outcome.

This may sound obvious, but is potentially one of the most abused aspects of fitness training.



Minimising Interference Effect and Maximising Training Effect.

So, should we avoid training endurance and strength during the programme? Not necessarily. A few simple tips can help you to maximise your results. Which is lucky, here’s why:

  • Strength training can improve endurance performance through improved economy, and improve velocity at lactate threshold (LT).
  • Sport involving strength, speed, power and endurance (football, rugby, hockey, etc) would be far less interesting if the players were either fit, strong or fast, and not a combination of these attributes.
  • People training for health/ body composition/ fitness goals for themselves (not necessarily competitive athletes) will often benefit from training both strength and fitness at the same time.
  • Lots more……

I won’t go into detail of long term programming here, but coaches/ athletes should be aware that certain times in the season may lend themselves to certain areas of development as a primary focus (eg football- may maximise strength in the off season etc). In addition, recognising the different effet of session frequency, duration and intensity will be crucial, and only briefly discussed here, so if you are a coach, make sure you read the suggested reading at the end of this document. Here’s 7 great ways how you can minimise the interference effect in your training programme.

8 Top Tips.

  1. Do strength training after endurance work– to ensure the best change of maximising signalling response for strength development, do strength training after endurance training, but only if you can reach the required intensity!
  2. Try to separate the sessions– for easy endurance/ technical & tactical sessions, aim to complete these sessions in the morning, followed by strength training in the early evening (after a minimum of 6 hours recovery time). For more difficult endurance sessions, a minimum of 24 hours recovery is recommended.
  3. Generally, you don’t need to train to failure– we can make good gains in strength and power by not going to failure most of the time. Getting the intensity high enough to promote a desired effect does not mean always training to failure, and during concurrent training blocks, the reduced stress may mean faster recovery and more effective subsequent sessions.
  4. If you don’t need to do lots of long endurance sessions, don’t!– strength and power is least compromised by short, high power intervals (including short, high intensity intervals). These can still promote a strong “fitness” response, whilst minimising interference effect. This approach may be ideal for athletes in intermittent sports. In addition, frequency of long endurance sessions (<20-30minutes, +3 days a week) will have a greater negative impact on concurrent training.
  5. Train heavy (>75% 1RM), with low reps (3-6)– This can help to minimise the fatigue associated with high volume training, and provide an adequate stimulus for strength development.
  6. Focus on Recovery! – maximising recovery through adequate sleep and nutrition, both in general and post workout, is essential to a successful training plan, and this importance is only enhanced when training multiple fitness qualities concurrently.
  7. Programme intelligently– split body routines in the day to day training variation may enable higher total training volumes (eg, train upper body to maintain quality through less localised fatigue), and in pure speed/ power related phases, reduce endurance training volume.
  8. Running is shown to have a higher detrimental effect than other forms of endurance training on strength/ power development– if you can select other training modalities then do, if you’re training for a run, consider points 1-7 as you need to run.

Hopefully this article has given you an insight into how to get the most out of combining your strength and endurance training, and indeed why it is important. Again, for most people, we can develop strength and endurance qualities at the same time. Optimising your programme means considering several factors, and making it work for you (and this includes time!). Some people will need to consider far more than what is discussed here, this is a small summary of a small area of things to consider- for others, just getting the work done will be the main factor. To get the most out of any training programme for strength and endurance benefits together, take the advice above, see if it’s realistic for you, take what you can, and go for it. Good luck!

Josh Kennedy MSc, ASCC


Suggested Reading:
Blagrove, R. Programmes of concurrent strength and endurance training: how to minimise the interference effect. Part 1: Evidence and mechanisms of interference. Professional Strength and Conditioning, (31), 7-14, 2013
Blagrove, R. Programmes of concurrent strength and endurance training: how to minimise the interference effect. Part 2: Programming Recommendations. Professional Strength and Conditioning, (32), 13-20, 2014
Wilson, J. Concurrent Training: a meta-analysis examining interference of aerobic and resistance exercises. Journal of Strength and Conditioning Research. 26(8), 2293-2307, 2012
Lewis, M. Strength Training and Endurance Athletes. Available via NSCA.
Subscribe to news Get in touch!