Wednesday, November 24, 2010

Concurrent endurance & strength training: Why the order matters

I started a really good post on running stuff, but then I got a great question from a guy who read an article of mine in Triathlete Magazine about the benefits of strength training; essentially he wanted to know if it's a bad idea that he strength trains right after teaching a 45-minute spin class. Plus, I had a great comment on a recent blog regarding the topic of concurrent training (i.e. combining your endurance and strength training into one workout session, and what the order should be). So, I decided to post part of the reader's question and the answer I gave. (If it's not obvious, I'm pretty passionate about these types of topics, which is why I'm willing to sit there and right a novel-ish email to a total stranger lol).

Ms. Prazak,
I have a question for you concerning your Run Less, Lift More, Race Better article in Triathlete magazine for August.... I was reading this article and came across the part of "keep em seperated". So I wanted to get your opinion on something:
I have become an avid triathlete the past two years, and i have started my base to prepare myself for my 70.3 training I have in May. I am a fitness instructor (spin and core stuff), and then I train 6 days a week on top of that. My typical schedule on a Wed and Friday is teach a 45 minute spin class and then I lift weights right after for 30-45 minutes. When you say "avoid strength training right after heavy endurance exercise", would a pretty laid back 45 min spin class (i do push myself and sweat, but it is nothing compared to my typical bike training) be considered "heavy endurance"? I understand that I shouldnt go on a 10 mile run and then lift weights. But what are your thoughts on lifting after a 45 min spin class?

Thank you for your time.


My response (which I sort of edited since I sent the email haha):

Hi Ryan,

Thanks for the email. There are several issues with concurrent endurance and strength training, so I'll try to tell the whole story of why this even matters and give you some recommendations on how you should structure your training...

Why it's NOT good to strength train after endurance exercise:

First off, there are issues of fatigue with concurrent training. You're likely to be more fatigued if you strength train after endurance and therefore your technique might suffer. If you're lifting relatively heavy weights, that could be a big problem. The fatigue may also prevent you from lifting to your potential so your strength workout won't be as quality as it would be were you "fresh." Some reasons for that may be: 1) lower glycogen levels post-endurance (even just 45 min of exercise), which impairs the anabolic (muscle growth) response of strength training; 2) endurance --> neuromuscular fatigue --> slowed muscle recruitment --> impaired rate of force development --> impaired power (no bueno). Now, all that said, if a 45-min bike isn't that big a deal for you, I'm sure it's not terribly detrimental to ride then lift (more on this below).

Secondly, with concurrent exercise there's hormonal/chemical issues. Endurance exercise prior to strength will suppress protein synthesis, which negatively interferes with gains in strength, power and hypertrophy, meaning you're not getting the max potential benefits from your strength workout. An enzyme called AMPK is released with endurance exercise, and AMPK inhibits markers of muscle growth, specifically a protein called mTOR (result: less protein synthesis is going on = your strength workout isn't reaching its potential). This effect can last up to 2-3 hours; the longer/harder the endurance exercise, the longer the effect.

However, strength training will not negatively affect your endurance capabilities; i.e. aerobic capacity and muscular endurance are not negatively affected with concurrent training. So lift away and you'll still be an aerobic machine. Plus, strength training is beneficial for triathletes/endurance athletes for a million reasons, and don't worry you won't bulk up as long as your endurance workouts are legit. But that's a whole other topic...

The bottom line:

It's best to separate strength and endurance training into two separate sessions hours apart when possible. But if you can't, there are two ways to go:
1) do the key workout of the day first so your most fresh for that, i.e. you get the most out of it.
2) do strength then endurance (for the reasons above).


Now, practically speaking:

Personally, I am forced to combine the two all the time due to time constraints. Most times, I like to do a short warmup (i.e. 10 min functional movement, 5-10 min treadmill), then a strength circuit, short rest, then endurance -- with quality nutrition throughout. But I switch it up if I need to be fresh/focused for the endurance workout. For example, I'm working hard on running technique these days so I'll sometimes do a 30-50 min easy/moderate run then strength train. (Described that workout in a recent post.) That said, I never do strength training after a long and/or hard run (hour+) or long bike (1.5+ hours).

I say, if the endurance workout is less that 60 minutes and not a total ball-buster, I think it's OK to do strength afterward without too many detrimental effects, though it's not ideal. Just rest about 10-20 minutes between and get in good nutrition during everything & after -- primarily glycogen, but protein too.

However, you might want to consider doing your strength first because it sounds like the spin class isn't that big of deal for you, and the strength is the focus. Thus you'll want the most gains from the strength and even 45 minutes spinning might elicit some fatigue, lowered glycogen, inhibition of protein synthesis, etc. So maybe try switching it up and see if you notice a difference!

Another option is combining lower-body endurance exercise with upper body strength, and vice versa. The inhibition of protein synthesis is localized to the muscles you use in the endurance workout, so if it's a bike ride, your legs release the AMPK, but your upper body will be relatively unaffected.

Hope that helps!



  1. I usually try to make my 2-3 days a week, shorter 5k run followed by interval training. If I teach spin or run longer, its usually a light conditioning (pushups, core, yoga). I love your passion for this! Thanks for the great advice!

  2. Hiya,

    Do you strength train year round?

  3. Great article and post. A much needed reminder for me that this needs to be part of my training. In collage our running coach would have us do our lifting or circuit training on easy days, but sometimes it was after an easy 8mile run and sometimes before...never really noticed a difference.

  4. Great post! Thanks for sharing this with us! Quick question though, I'd like to start a strength training routine now over the winter and was wondering what type of exercises you suggest? I'm a triathlete...if that helps!

  5. Love the post! And very timely too with the offseason strength training ramping up for folks

  6. Great post. Finally someone put out some information regarding strength training as more than just an after thought to miles and miles of endurance training. Loved the article and this post was great info.
    Some programs recommend 3-5 hours between strength/endurance workouts - do you think that is adequate to reignite protein synthesis, or do you think a longer spread is necessary?

  7. Tawnee!!! You animal!

    How about this:

    Would you agree that strength training, ideally, has a lot of compound movements/involves more than one muscle group? If we agree on that (say generally, agree, as I know there may be benefits of isolation), what are your thoughts on these?

    * Do primarily lower body training (ie. legs) before/after a swim workout (which primarily works the upper body)

    * Do primarily upper body strength training after a bike and/or run and/or bike/run (say that 3 times fast!) workout

    Let's say core work is negotiable on either an upper body or lower body strength session, so long as you get it done!

    ps- I've totally bought into the functional strength training thing, and the bosu ball is my best friend at the moment (that is, until my gym gets TRX straps).


    hope you had a good thanksgiving!

  8. Hi, I´m brasilian amateur triathlete and I´m adding a strength training im my program, so I was looking for some informations and found it in your blog/article. Very good tips, tks. Carol

  9. Since I started reading your blog I have done more strength training for sure and see a difference. It is hard (because of time) for me to separate my endurance and ST into 2 sessions, but I will make more of an effort to do so after reading this.