Does HIIT Lower Testosterone? Here’s What Science Says!
High-intensity interval training has been all the roar in the fitness world for quite some time now. This brilliant form of alternating between low-intensity and high-intensity exercise periods can supposedly melt fat and build muscle at the same time. However, is it any good for our hormones? And more importantly – does HIIT lower testosterone?
HIIT has been shown to only slightly reduce testosterone levels in a particular 2016 study involving obese women as test subjects (1).
However, keep in mind that there are many studies that support HIIT’s effectiveness at naturally increasing one’s testosterone levels!
There’s even a Journal of Endocrinological Investigation research, which shows that high-intensity interval exercise boosts free testosterone more than regular (steady-state) cardio (2)!
So you can find plenty of scientific data that points out at HIIT’s obvious T-boosting capabilities.
But first – let’s see what this exercise protocol is all about…
What is HIIT?
HIIT (high-intensity interval training) is a specific workout that incorporates periods of intense periods, followed by lower-intensity recovery periods.
These intervals between hard and easy continue until you’re too exhausted to continue since there’s no universal duration for each session.
Still, HIIT sessions are generally very short in duration since most don’t go beyond 30 minutes.
- Also read: Does working out increase testosterone?
But how long your session will last totally depends on your fitness levels and the overall physical condition.
And don’t forget that other synonyms of HIIT that you can come across include SIT (sprint interval training) and HIIE (high-intensity intermittent exercise).
Here’s how it works:
- Sprint for 30 seconds (100% intensity)
- Walk or jog slowly for 1 minute (50% intensity)
This is an example of a typical HIIT workout, although you can change the exercises as per your own preferences and goals.
Moreover, there are 5 main HIIT protocols that you can stumble upon and they are the:
- Peter Coe
Despite all the variations though, it’s all about alternating between high-intensity and low-intensity.
Sample HIIT Workout at Home
Here’s a very simple and beginner-friendly HIIT workout that doesn’t require any weights or fancy gym equipment:
Rounds: 3 | Exercises: 5 | 30 secs high-intensity / 30 secs rest
- Mobility twist
- Knee push-ups with mountain climbers (two repetitions of each)
- Squat into a lunge
- Walkout into plank and back
- Single-leg crunches
Feel free to check the video above if you’re unsure how to do any of these exercises.
Also, note that each round takes roughly 5 minutes to complete and you have to do a total of 3.
What Does Science Say About HIIT and Testosterone?
There’s plenty of scientific data that points out just how effective high-intensity interval training is at naturally increasing testosterone levels.
And now we’re going to take a closer look at 4 relevant studies that support these claims!
1. HIIT Stimulates Free Testosterone More than Regular Cardio
The Department of Exercise & Sport Science from the University of North Carolina examined the impact of high-intensity interval exercise (IE in this case) and steady-state endurance exercise (SSE) in Dec 2012 (3).
So researchers decided to test both methods on 15 endurance-trained men by setting the following conditions:
- IE consisted of intense 90-second periods on the treadmill, followed by 90-second recovery periods at 40% intensity
- SSE consisted of running at a steady intensity of 60-65% throughout the workout
Both workouts lasted roughly 45 minutes and both had the same work output.
Scientists found that the high-intensity workout produced a more pronounced increase in free testosterone than its steady-state counterpart!
2. Moderate-High Intensity Training Boosts T and Lowers Body Fat in Obese Young Men
Back in Sept 2012, Iranian researchers from the Iranian Journal of Endocrinology and Metabolism studied how interval training affects certain hormones such as cortisol, leptin and testosterone (4).
The test subjects observed were 18 young overweight guys who were previously sedentary.
And they had these men engage in moderate to high-intensity interval workouts 3 times a week for a total of 16 weeks with the following details:
- 8 to 10 rounds of 4-minute running at 60 to 90% intensity, followed by 2-minute rest intervals at 40 to 50% intensity
This not only resulted in improved testosterone levels, but these men also benefited from a reduction in their waist circumference and body fat levels!
3. HIIT Increases Free T and Peak Power Output in Masters Athletes
In a 2017 study, researchers from the UK tried to see whether or not HIIT can be as beneficial to masters athletes as it is to sedentary aging men when it comes to boosting peak power output (5).
There were 17 test subjects (men, masters athletes) aged around 60 who were involved in high-intensity training sessions over the course of six weeks.
The protocol consisted of:
- x6 30-second sprints followed by 3 mins of active recovery
Eventually, researchers found that HIIT helped to increase the power output, free testosterone and even total testosterone (albeit not that significantly) in masters athletes.
4. HIIT Elicits a Higher Increase in T Levels Compared to High-Volume Training
A 2013 study published in the Hormone and Metabolic Research journal compared the metabolic, psychological and hormonal responses to 2 popular training protocols – high-intensity training (HIT) and high-volume training (HVT) (5).
The scientists used 12 guys as test subjects who performed the following workout protocols:
- HVT – 130 mins at 55% peak power output
- HIT – 4 rounds of 4 minutes each at 95% peak power output
- HIT – 4 rounds of 30 seconds at maximum (all-out) intensity
Then they compared how cortisol, human growth hormone and testosterone were affected by these workouts.
Long story short, they concluded that high-intensity training produces a more pronounced increase in human growth hormone and testosterone than high-volume training.
What Exercise Increases Testosterone Most?
Strength training (or weightlifting) is undoubtedly the best type of exercise to naturally stimulate your testosterone production.
Or in other words, this means that hitting the gym is optimal for stimulating your own T production as that’s where all the heavy weights are located (unless you have a gym at your home).
Compound exercises such as deadlifts, squats and bench press are prime examples of brilliant multi-joint movements that trigger the biggest hormonal response.
Studies show that free-weight (i.e. compound) movements like squats induce a greater hormonal response (including more testosterone) than machine exercises like the leg press (6).
Let’s now check some relevant studies that support the superiority of strength training for boosting T levels!
30 Mins of Heavy Resistance Training Increase T by 21.6%
A 1983 study published by the European Journal of Applied Physiology and Occupational Physiology examined the testosterone response to weightlifting in men and women (7).
On one hand, guys logically experienced a more prominent boost in their T levels than women in relation to lifting heavy weights.
But men saw a 21.6% increase in their testosterone, immediately following a 30-minute strength training workout!
Lifting Heavy Weights Leads to 19.6% Increase in T Immediately After a Workout
That’s what scientists from the Faculty of Sport and Physical Education (University of Belgrade, Serbia, EU) have found, based on specific requirements (8).
The optimal training conditions that they observed include the following criteria:
- Sets – 11
- Reps (per set) – 3
- Rest (between sets) – 5 mins
- Intensity – 90% 1RM (of your 1 rep maximum)
Can Working Out too Much Lower Testosterone?
Absolutely – overtraining has been scientifically shown to decrease testosterone levels, according to a study published in the journal of Fertility and Sterility (9).
In fact, the same study points out that it took 3 months for the T levels of test subjects to their normal, pre-overtraining values!
Even worse, sperm count was reduced by a whopping 52% after 3 months, although the conclusion is that this shouldn’t affect fertility (thank the Lord)!
So, will HIIT reduce testosterone?
Only if you overtrain and/or if you’re an obese lady suffering from polycystic ovary syndrome, as mentioned in the study we cited at the beginning of this article!
Otherwise, high-intensity interval training is an exceptional tool for optimizing your natural T production and building quality muscle.
Also, it does a great job of helping you shed excess amounts of body fat.
But have you ever tried a HIIT workout yourself?
And if you did – how was it?
Let us know by leaving a comment below!