So a while ago, I wrote an article about the upside of interval training in lieu of long slow distance (LSD) cardio. And I have come to realize… that I may have been wrong.
To summarize that article, I argued that interval training improves your anaerobic capacity better than LSD, improves aerobic capacity the same if not better, decreases the risk of sustaining chronic injuries, decreases the time needed to actually complete the training, decreases body fat more effectively, preserves muscle more effectively, and helps preserve strength and power. All pretty awesome things. If you want to read the actual article, here you go.
Well, not satisfied by just writing about it, I decided to put my money where my mouth is. Since writing the original article on April 22nd, I have done nothing but interval training for my conditioning work and have continued my strength training as normal. Prior to this, my ‘cardio’ consisted exclusively of taking my dog for a daily walk. Here’s what happened over the past month and a half.
(Note: this was not a controlled study or anything like that. This was not conducted by university professors with outlines and parameters to ensure absolute certainty in their findings. Just my own day to day feelings, observations, and empirical data.)
Here is a basic outline of what I’ve done for the past 45 or so days.
Monday – strength train (full body routine)
Tuesday – high intensity intervals
Wednesday – strength train (full body routine)
Thursday – tempo runs
Friday – strength train (full body routine)
Saturday – high intensity intervals/tempo runs
Sunday – off/tempo runs
April 22nd Measurements
- Resting heart rate: 65 bpm, give or take a few beats
- 1 minute heart rate recovery (after elevating my heart rate, how much does my heart rate decrease after 1 minute): about 20 beats
- 2 minute heart rate recovery: about 35 beats
- Weight: 183.5lb
- Muscle mass: 89lb (measured using the InBody body composition analysis)
- Percent body fat: 14.9% (measured using the InBody body composition analysis)
- Trap bar deadlift: 315×6 on a good day
- Hip thrust: 500×5
- Sleep quality: good but not great
June 10th Measurements
- Resting heart rate: 50 beats per minute
I measured my heart rate this morning after laying down for 2 minutes
- 1 minute heart rate recovery: 34bpm
- 2 minute heart rate recovery: 51bpm
- Weight: 182.1lb
- Muscle mass: 91lbs (measured using the InBody body composition analysis)
- Percent bodyfat: 13.5% (measured using the InBody body composition analysis)
- Trap bar deadlift: 315×10
- Hip thrust: 520×5
- Sleep quality: can’t remember the last time I didn’t sleep through the night to be honest (unless woken by an outside source like a dog)
So clearly you can see improvements across the board. My conditioning consisted of tempo runs and shuttle runs almost exclusively, with some intervals on the rower sprinkled in periodically. It’s also worth noting that my longest conditioning session lasted about 30 minutes, which is right around the average length of steady state cardio sessions for a majority of people (this is strictly based off of my 8 years experience in the fitness field, I don’t have factual data to make this claim. Sue me.)
I would also argue my strength gains are more of a result of the tweaks I made in my strength training program rather than with my conditioning. However, would they still have occurred had I slaved away for 30-45 minutes performing long, slow distance type cardio 3-5 times per week? Who knows. Although, my guess is it would have lessened it to a degree because of the competing demands being placed on my body. Again, see the original article if you don’t know what I’m talking about.
Now the glaring issue that stuck out to me while writing this was ‘what is preventing me from just lying and making up results to support my claim that intervals reign supreme in the world of cardiovascular exercise?’ Well, to be honest… nothing. You just have to trust me. I don’t receive financial compensation for views on this site, no sponsors backing me, no products to push, nothing along those lines. I have no reason to exaggerate my results to prove a point. I literally gain nothing from it. I’m just trying to help whoever reads this reach their fitness goals in the most optimal, safest way possible.
And come on, does this look like the face of a liar?

Yours truly, circa 1993 or so
So my personal results are here as proof and I still stand by what I said. In terms of bang for your buck, interval training remains the best method for cardiovascular training (with the exception being, of course, if you run marathons).