Cardio vs. strength training

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Episode 11

TL;DR
  • Cardio and strength training offer distinct health benefits, such as:
    • Improving endurance, cardiovascular health, and fat loss for cardio.
    • Increasing strength & muscle mass and better hormone regulation for strength training.
  • Options to program the 2 optimally:
    • Make the muscle-strengthening session a cardio one.
    • Separate the 2 by at least 6 h.
    • One after the other.
    • A mix of the 2.

If I’d had the hindsight I have today (and the results of studies that weren’t available then anyway), I could clearly have envisaged better endurance performances (middle-distance in particular), with more appropriate muscle strengthening. Because yes, the two are indeed complementary. Today’s topic is a question of arbitrage: should we optimize each type of training specifically, or find a compromise between the two, notably for reasons of practicality (we’re not all professionals and have other constraints)? Let the match begin…

Why cardio or strength training?

Cardio1, or training focused on endurance exercises, is known to have a number of health benefits:

  • Building endurance
  • Improving cardiovascular health
  • Lowering blood pressure
  • Maintaining healthy cholesterol levels
  • Reducing body fat
  • Etc.

Strength training2, or training focused on muscle strengthening, also produces significant health benefits:

  • Building strength
  • Increasing muscle mass
  • Improving bone density
  • Strengthening ligaments and tendons
  • Regulating hormone levels
  • Etc.

That’s why it’s more than tempting to want to reap these benefits by working on both dimensions. Separately? Successively (which one before the other)? A mix of the 2?

How to program the 2

To be able to work on the 2 types of exercise, there are several possibilities open to us:

  • Make the muscle-strengthening session a cardio one: Having already been out of breath following a muscle-strengthening exercise (particularly in long sets), I wondered whether the latter wasn’t already working my cardio. And I’m not the only one to have wondered this, since a publication3 has looked into the matter. Conclusion: yes, as long as the session is of “adequate intensity”, defined as 60% of maximum heart rate. To estimate the latter (in the absence of a smartwatch), simply take the difference between 226 (for women) and 220 (for men) and your age. For the more inquisitive among you (and after a quick mental calculation), how old would you think I am if I told you that would be a heart rate of 109 beats per minute for me?
  • Separate the 2 by at least 6 h: Researchers4 have taken a good look at the question of separate trainings and concluded that, for a “complete adaptive response” (i.e. optimized results), there should be a recovery period of at least 6 h between the 2. The two qualities, endurance on the one hand and strength on the other, seem to require competing approaches… Ok, but what about when you can’t afford the luxury of 2 separate sessions, or when the activity you’re training for (boxing comes to mind in my case) requires precisely these 2 qualities simultaneously?
  • One after the other: You’ve probably already seen some gym-goers start their session with a half-hour of moderate-intensity cycling, and finish it with running or brisk walking on a treadmill. Is this activity to the detriment of muscle strengthening? A previous study5 seemed to have concluded that the order of the 2 types of exercise made little difference, but a more recent study from 20206 (admittedly, on a population of obese men) this time gives a slight advantage to finishing the session with endurance, on each of the indicators monitored, notably fat loss.
  • A mix of the 2: The University of California compared7 the effects of the previous option or “serial“ concurrent training with “integrated” concurrent training, as we’ll see. The 2 groups (too bad there were no control groups with only one or the other) performed what the researchers called “the same amount of work”. But the protocol for the second variant was – in simplified terms – to do a 30-60 s sprint (the benefits of which we’ve already praised) just before each set of resistance exercise. 9 indicators were selected to monitor changes in endurance, strength and flexibility (differentiating between upper and lower body), as well as body composition. The participants improved overall in 11 weeks, but the question was which group was the most effective. I’ll leave you to look at the details, but it’s fair to say – assuming the choice of exercises – that the integrated variant prevailed (6 out of 9 indicators). Yet, there was a slight advantage in strength for the serial variant and an advantage in endurance for the other. This was rather expected. But the 991% difference on the body fat indicator is impressive. Also surprising is the 144% improvement in upper body flexibility. In short, to put it another way, mixing endurance and strength helped burn 10 times more body fat while developing muscle and flexibility – huge!

Remember that the question of associating cardio and strength training depends partly on your objectives (as is often the case) and partly on your constraints. If you want to optimize your results, separate them (I’d even say into 2 different days). If you really don’t have the time, there are other parameters to consider. As a beginner, a fairly intense strength training session will be enough to work your cardio at the same time. The more comfortable you become, the more you’ll be able to move towards circuit training8 sessions, a topic that might merit a specific focus. The latter offer the prospect of incredible results, but also a greater risk of injury, since your execution technique can quickly deteriorate with fatigue. Other topics that deserve to be addressed separately: recovery and rest.

Here’s a personal hack: running to and from the gym. I consider the session to start when I leave the house. On the outward journey, a jog, particularly to music, not only allows me to warm up but also to condition myself psychologically. On the way back, I know I can expend the rest of my energy over half the trip (a kind of sprint) and then walk home for a gradual cooldown

Fun fact

The burpee is a full-body exercise considered to be a good compromise between cardio and strength training. It was invented in 1939 by American physiologist Royal Huddleston Burpee Sr. as a means of assessing physical fitness. It was later appropriated by the US Army on the eve of the Second World War. The aim was to test the number of times a new recruit could perform it in 20 s: 8 burpees were considered mediocre, 10 correct, 13 or more excellent.

Going further

References

  1. https://en.wikipedia.org/wiki/Endurance_training ↩︎
  2. https://en.wikipedia.org/wiki/Strength_training ↩︎
  3. Morra EA, Zaniqueli D, Rodrigues SL, et al. Long-term intense resistance training in men is associated with preserved cardiac structure/function, decreased aortic stiffness, and lower central augmentation pressure. J Hypertens. 2014;32(2):286-293. doi: 10.1097/HJH.0000000000000035. https://pubmed.ncbi.nlm.nih.gov/24351804/ ↩︎
  4. Robineau J, Babault N, Piscione J, Lacome M, Bigard AX. Specific Training Effects of Concurrent Aerobic and Strength Exercises Depend on Recovery Duration. J Strength Cond Res. 2016;30(3):672-683. doi: 10.1519/JSC.0000000000000798. https://pubmed.ncbi.nlm.nih.gov/25546450/ ↩︎
  5. Davitt PM, Pellegrino JK, Schanzer JR, Tjionas H, Arent SM. The effects of a combined resistance training and endurance exercise program in inactive college female subjects: does order matter?. J Strength Cond Res. 2014;28(7):1937-1945. doi: 10.1519/JSC.0000000000000355. https://pubmed.ncbi.nlm.nih.gov/24378658/ ↩︎
  6. Bagheri R, Moghadam BH, Church DD, et al. The effects of concurrent training order on body composition and serum concentrations of follistatin, myostatin and GDF11 in sarcopenic elderly men. Exp Gerontol. 2020;133:110869. doi: 10.1016/j.exger.2020.110869. https://pubmed.ncbi.nlm.nih.gov/32035222/ ↩︎
  7. Davis WJ, Wood DT, Andrews RG, Elkind LM, Davis WB. Concurrent training enhances athletes’ strength, muscle endurance, and other measures. J Strength Cond Res. 2008;22(5):1487-1502. doi: 10.1519/JSC.0b013e3181739f08. https://pubmed.ncbi.nlm.nih.gov/18714239/ ↩︎
  8. https://en.wikipedia.org/wiki/Circuit_training ↩︎