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.

Starting Your Fitness Journey

What’s the best way to start your fitness journey?

At the start of this week, I decided that I was going to challenge myself. As you may have seen from my previous post, my goal was to get to my best level of fitness ever. This meant stronger, faster, fitter… all in 8 weeks.

First, it’s important to put this into context as to why i feel this is even close to possible. If I was currently inactive, I wouldn’t consider it. If i was recovering from injury, I wouldn’t consider it. If I was unsure how to approach an all out training programme safely (and without impacting on my already busy schedule), I probably wouldn’t do it either. But the fact is, I think I can do it. I have been training recently, just not focused or consistently. I’m particularly weak after an illness over the Christmas period leading to a large weight loss (which is still not all back on).. and I’ve always been able to adapt pretty quick to endurance training. My nutrition has been poor recently, and I’ve lost track of where I’m up to with energy intake, protein intake and other key features of good nutrition. Most importantly though, with enough commitment, I’m confident i can balance my training enough to be in “good condition” in several areas. I’m simply looking to apply myself in an intelligent manner, to get back to feeling my best. After all, it’s what I aim to do on a daily basis for several of my personal training clients, and balancing different stimulus is not only required, but often optimal for a lot of the athletes i work with as a strength and conditioning coach. So, it may seem like a mountain to climb, but actually, I simply need to balance several training requirements around a busy schedule, and optimise adaptation and recovery.  Sound familiar? If not, should it?

So, how to start?

Well, the first step is to be clear on what you want to achieve. This was discussed in my previous post see it here. 

Once you’re clear on what you want to achieve, we need to start by finding out where you are in relation to where you want to be. This may mean those dreaded before photos, weigh ins, food diaries, strength and fitness testing specific to your goals (mine involved all of this, and was tough!). This was made far easier by using our new FX Fitness Experience App (launching to everyone soon!) to keep all of my results (including photos) in one place. I’d also suggest using my fitness pal to keep a food diary (this links automatically with the app), but is a great tool not only for you, but also for your PT in seeing where you’re at. Take a look at the end of the article to see what tests i used for my journey and why.

Alongside this, you need to have a clear picture of the time you have (or can make) available to train. If we have your current fitness levels (as tested), your current screening results, previous fitness levels, pre programme exercise routine, injury history and current schedule, we can look to build a well rounded programme to get you moving towards your goals efficiently. REMEMBER, THE MOST IMPORTANT ASPECT OF ANY GOOD TRAINING AND NUTRIITON PROGRAMME IS ADHERENCE. Start with something you can stick to, if not, adapt it so you can. I guarantee having a plan for 4x per week with recovery work will be more beneficial after 6 weeks of doing it than a plan of 6x per week that you don’t do. Within the training programme, knowing where we are and what we want to achieve, and the time we have available to commit to this, we can set TARGETS. These can be the Specific, Measurable, Attainable, Realistic and Time bound, goals, with number to look at to evaluate your performance. For example, the numbers in testing here will come into play (eg, 100kg back squat may aim for 110kg in 8 weeks). From a nutrition perspective, after a short food diary (3-5 days), we should have enough basic information (combined with your training programme) to set some initial targets for your nutrition to help you meet your goals. For the quickest adaptation, this should at lease include calorie targets, protein targets, guidelines to help you keep “high quality” levels of nutrition, along with some basic advice on meal timings and supplement options.  Also use targets for those little but important achievements- did you track your nutrition? Great! Did you get done what was on the Plan (even if this means RECOVER)? GREAT! Did you get a full week exactly on plan? GREAT!!! These smaller goals are the thing that will determine success long term, not the first change on the scales, so make sure you give yourself credit for achieving them!

Remember, having the ability to review and evaluate a programme can be invaluable in long term success. Always ensure you work with your PT (or coach), let us know what you’re doing by tracking nutrition and exercise, and trust us to work with you, and adapt the plan IF and WHEN we feel it’s needed.

So, there it is, four crucial aspects of getting started on your fitness journey (or started on this stage of your fitness journey).

  1. Have a clear Goal.
  2. Find out where you’re at (Lifestyle, available time, current weight, current relevant fitness, current health, current nutrition).
  3. Set targets, and set a plan. Not only starting the actual programme (setting the workouts and nutrition numbers) but also the SMART targets to measure your success. These can be long term (bodyweight, body composition, strength, etc), or can be daily goals (workout? Tracked diet? No takeaway!?).
  4. Communicate with your trainer. If you’re struggling, let your trainer know. There may need to be a simple change, or there may not need to be a change at all. But good communication is key.

If you’re currently not on top of any of these aspects in your fitness journey, then you’re missing out. Remember, this is the first step, the basics. Underrated, but the rest is built from this. If you feel you’re missing any of these aspects, please feel free to get in touch over social media (links on the first article) or email

“To be Successful you don’t have to do extraordinary things, you have to do ordinary things extraordinarily well”- Jim Rohn 

My Week- Fitness tests, Pepsi and Sore Legs.

Just a quick rundown of my first week… Here’s my fitness testing schedule:

Monday – Still deciding. Then committed to the change (starting Tuesday). Planned nutrition. 

Tuesday- Weigh in, photos. Bench and Deadlift.

Wednesday- Pull ups and Power Clean. 

Thursday- Cooper run (12 minutes maximum distance).

Friday- Snatch and Front squat. 

Saturday- 5km time trial. 

Sunday- Off. 

Important points. I was sore from the tests. Sore to the point I almost moved them to get a more “valid” result. BUT, I didn’t. my training goals are to improve overall strength and fitness. Surely this must include an improved ability to recover. So I didn’t change the days. I warmed up, a lot. I made sure I was doing what I could to optimise recovery (as much sleep as possible, fast glycogen replenishment after training (hence the “full fat” pepsi over the water after my cooper run) and generally adequate nutrition (including supplements)). But, I got through it, and actually felt great by the end of the week (aside from still side stepping down stairs). So, I now have my starting point.

In addition, I have some great topics that i want to cover already over the next 8 weeks, including strategies to enhance recovery, my supplement stack review, concurrent training and interference effect and more! So keep up to date. Thanks!




Josh’s 8 week Challenge. Who, What and Why?


Allow me to introduce myself. I’m Josh, one of the directors of FX Fitness Experience. I’m a fully qualified personal trainer, an accredited strength and conditioning coach and NOT an athlete. I have a BSc in Sport and Exercise Science from the University of Cumbria, and an MSc in Strength and conditioning from the University of Central Lancashire. Since 2011, we’ve been dedicated to helping you achieve your performance, health and body composition goals. I’m used to having a busy lifestyle (as all fitness professionals, MSc Students and Business owners will likely know), but I’ve found over recent years that the “compromise” is my own fitness goals. To find out more about me, check out my Bio Page here.

For the next 8 weeks, I’m going to set myself a challenge. I want to improve everything that’s important to me in my own fitness journey. Recently, I’ve been ticking over with my training. I’ve done enough to stay in reasonable condition, but I’m ready to challenge myself, to see what i can do within this time. So, here are my goals. I want to lift.. well. I’m aiming to achieve personal bests in the snatch and clean and jerk.. the Olympic lifts… my personal favourite lifts, and ones I’ve neglected in recent months. This means not only will i look to continue to develop my technique, but also my strength. And if strength is going to be relevant, why not add an element of that into my goals. I want to PB in the front squat, deadlift and bench press too. Because why not. I suppose that’s pretty simple though. Simply improving technical skill and gaining strength and power should get me at least close to these goals. The issue (potentially) is, I need to run. I have a half marathon booked in about 8 weeks time. I’ve done several before, but always found it difficult to maintain my strength when adding a lot of running into my training. So, what’s going to give?

Nothing. I want to PR in that too. After all, I’m the lightest I’ve been for a while! Lastly, I want to look and feel in better shape- and to be honest for me, this means building some muscle mass and dropping a bit of fat. When I thought about it, I realised something. I want to get stronger, fitter and look in better shape- and who doesn’t?!  So that’s it, Clear goals for what i want to achieve.

The difficulty is, in theory, they work against each other. Building strength and improving key lifts (including the Olympic lifts) can work together well, but trying to balance this with a very limited timeframe to make huge gains in distance running performance, well that’s ambitious. On top of that, expecting to build muscle mass to the level of improving aesthetics alongside everything else, makes things difficult.

So, I thought what better way to approach this, than let you all know how I approach this, and why. I don’t expect anyone to read everything, or much to be honest, but if any aspect of this journey jumps out at you as helpful (Getting started….concurrent training, competing adaptations and interference effect…. optimising recovery….. monitoring training… useful technology in strength and endurance performance…. and many more! ), give it a read, follow the advice, and get yourself on the right path!

Thanks! If you have any questions, just let me know via email on, or via my social media (links below).




If you don’t already follow the pages, make sure you do, as these will contain additional video guidance for some of the key things to consider. Thanks, and wish me luck!