Testosterone is probably the most discussed hormone in the fitness industry, largely due to its role in hypertrophy.
Firstly, it’s worth establishing some basic details.
Under normal conditions, It’s very broadly estimated around 70% of total testosterone is strongly bound to SHGB (that is, sex-hormone-binding globulin), 20-30% weakly bound to albumin, and the remaining 1-2% is bound to nothing, and called free testosterone.
Testosterone strongly bound to SHBG cannot have an active effect on tissues. Testosterone bound to albumin, due to the binding being weak, can actively impact tissues. Free testosterone, of course, is freely capable of exerting effects too.
When administered exogenously to evoke sustained elevations above normal levels, we know it can powerfully enhance hypertrophy adaptations in response to lifting weights.
However, what about the somewhat inverse of this?
Does lifting weights increase testosterone?
In a previous article, we saw that lifting weights can temporarily spike testosterone concentrations. But In this particular video, we’ll be focusing on if lifting weights can chronically increase your resting testosterone levels.
This seems like a straightforward question. Yet, closer inspection would reveal an array of factors worth considering.
- Are we talking previously untrained or trained individuals, young or older individuals?
- What are the baseline testosterone levels of the person in question?
- What were the training variables and exercises used?
- Finally, are we talking about total testosterone, free testosterone, or bioavailable testosterone (note, bioavailable testosterone refers to both albumin-bound and free testosterone)?
Accordingly, as we dissect the current existing literature, we’ll do our best to ensure these factors are considered.
Let’s dive in.
Table of Contents
Firstly, a recent 2021 meta-analysis by Potter et al. combined findings of 9 randomized control trials, all conducted on previously un resistance-trained men ranging from 18-75 years old.
The normal total testosterone range for men roughly lies between 270ng/dl to 1070 ng/dl, and the subject’s average levels in these 9 studies fell within this range.
Most studies had subjects perform 2-3 full-body workouts a week, with mainly compound exercises comprising the program, with movements like the leg press, bench press, and lat pulldown commonly used. Largely 6-12 weekly sets were performed for the trained muscle groups, with repetitions performed to or very close to failure with loads between 50% and 80% one-rep max.
Below are the approximate results, indicating lifting weights had no significant effect on resting total testosterone concentrations.
A 2018 meta-analysis by Hayes and Elliot further supports this conclusion, with older men.
17 randomized and unrandomized control trials conducted on previously un resistance-trained men at or above the age of 60, with the large majority of subjects still within the normal total, bioavailable, or free testosterone ranges, were combined.
Like before, most studies included 2-3 full-body workouts per week, with mainly compound exercises comprising the program, with movements like the leg press, bench press, and lat pulldown commonly used. Largely 6-12 weekly sets were performed for the trained muscle groups, with repetitions performed to or very close to failure with loads between 50% and 80% one-rep max.
Below are the findings, indicating lifting weights did not have a significant effect on free, bioavailable, or total testosterone resting concentrations.
What About Other Individuals?
So, the two detailed meta-analyses indicate in men of varying ages, lifting weights does not impact resting testosterone concentrations.
However, it’s worth reiterating all this data was derived from previously untrained men who were largely within normal testosterone ranges.
What about trained men, or men with low total testosterone concentrations (roughly defined as below 270ng/dl)?
Could lifting weights impact resting concentrations in either of these demographics?
Individuals With Below Normal Testosterone Levels
Exploring the low testosterone demographic first, 3 comparable randomized trials (one, two, and three) out of Denmark recruited men between 60-78 years old, with low bioavailable testosterone concentrations (the average levels were around 129ng/dl) and a waist circumference greater than 94 centimeters.
These studies set out to examine the effects of exogenous testosterone treatment (in the form of gel) with resistance training. However, they were groups that only resistance-trained with a placebo gel.
Subjects trained 2-3 times per week for 10 weeks.
They trained leg presses, knee extensions, leg curls, chest presses, lat pulldowns, back extensions, and crunches for 2-3 sets with reps very likely to or close to failure with 6-10 rep-max loads.
In all three studies, the placebo group that resistance-trained did not experience increases in bioavailable testosterone. Indicating even in older men with low testosterone levels, lifting weights may have no effect on resting testosterone concentrations.
As for trained individuals, a couple of studies provide insight.
Schwanbeck et al. had 15 men with an average of around 2.5 years of training experience perform a free weight or machine-only program.
The respective group’s programs are on-screen. Each exercise was trained for 3-4 sets of 4-10 reps.
This study assessed free testosterone, with baseline measures being in the normal range. After the training period, neither group experienced any changes in resting concentrations.
Mangine et al. had 33 men with 2 years of average training experience perform a range of exercises.
One group trained each exercise for 4 sets of 3-5 reps with 90% one-rep max loads, while another group used 4 sets of 10-12 reps with 70% one-rep max loads.
Subjects were within the normal total testosterone ranges. After the study, neither group experienced any changes in resting total testosterone concentrations.
Mccall et al. recruited men with prior training experience (no further details were given) who were within the normal total testosterone ranges.
They trained 4 biceps exercises and 4 other exercises (again, no further details were given) for 3 sets with a 10-rep max load.
After 12 training weeks, resting total testosterone concentrations were unchanged.
Finally, Ostrowski et al. had 35 men with 1-4 years of training experience train a range of exercises for sets of 7-12 repetitions to failure.
Some subjects trained each exercise for 1 set (the low volume group), some 2 sets per exercise (the moderate volume group), and the rest used 3 sets per exercise (the high volume group).
Neither group experienced statistically significant changes in total testosterone resting concentrations as a result of training.
I should note the data of this study was kind of all of the place, as you can see with the numbers provided below. The data was highly variable (as indicated by the standard deviations), making it difficult to decipher anything.
Studies Finding an Increase in Resting Testosterone Levels
So, all the data assessed so far indicates lifting weights has no impact on resting testosterone concentrations. Yet, I’m aware of two studies contrasting with this.
Izquierdo et al. had Spanish nation team basque ball players with resistance training experience, and within the normal total testosterone ranges, train the parallel squat and bench press twice per week for 11 weeks.
Subjects were either allocated to a failure or non-failure group.
During the first 6 weeks, the failure group trained each exercise with 3 sets of reps to failure with a 10 rep-max load, while the non-failure group used 6 sets of 5 reps with a 10 rep max load.
Throughout this period, neither group experienced changes in resting total testosterone concentrations.
During the next 5 weeks, the failure group trained each movement with 3 sets of reps to failure with a 6 rep-max load, while the non-failure group used 6 sets of 3 reps with a 6 rep-max load.
Throughout this period, the failure group’s resting total testosterone concentrations remained unchanged, but the non-failure group’s resting total testosterone concentrations were increased.
Thus, perhaps compound exercises with heavy loads, but only performing a few repetitions, alters total testosterone resting concentrations.
However, it’s difficult to verify this claim as there are no similar studies as far as I know. The closest paper was the previously mentioned Mangine et al. study, which found in one group of subjects training a range of compound exercises for 3-5 reps with 90% one-rep max loads, resting total testosterone concentrations remained unaltered.
Still, differences between these two studies, such as the precise training variables and participants exist.
As for the second study, Kraemer et al. had 8 young men (with an average age of 30) and 9 older men (with an average age of 62), within the normal testosterone ranges, train a range of exercises with the loads used varying across the three training days per week.
Throughout 10 weeks of training, neither the young nor older men experienced increases in resting total testosterone concentrations. But, the young men did experience increases in resting free testosterone concentrations, this was not the case for the older men.
Despite this finding, a comparably designed study by Petrella et al. conflicts.
13 young men ( between 20-35) and 13 older men (between 60-75) trained the leg extension, leg press, and squat each for 3 sets of 8-12 repetitions, three times per week for 16 weeks.
Neither the young nor older men experienced an increase in resting total or free testosterone concentrations.
Though, it’s still worth noting exercise selection did differ between this study and the one by Kraemer, so it’s not clear if this may explain the divergent outcomes.
In summary, the majority of evidence indicates in a wide range of individuals, lifting weights does not appear to increase resting total, free, or bioavailable testosterone concentrations.
Yet, it’s worth considering this data does not necessarily prove lifting weights never increases resting testosterone concentrations.
It remains plausible that training variables could matter. Virtually all of the data we assessed had subjects train with full-body splits, but what about something like bro-splits. Moreover, minimal data explore the effects of training with loads above 80% one-rep max, as well as different proximities from failure.
Finally, virtually all of the data assessed lasted 12 weeks or less. What about many months or even years?
For example, Hakkinen et al. found after following up on elite weightlifters for 2 years, their resting total testosterone concentrations had elevated. However, there are two problems with this data.
Firstly, they were weightlifters, and as such would have been regularly training Olympic lifts, which is not what most recreational or competitive individuals after muscle hypertrophy or typical strength gains would do. It’s not clear how this would influence things.
Secondly, although the researchers stated they were not taking anabolic steroids before or during the 2 years, I’m a little skeptical of this as they were established champions or record holders in Finland with impressive numbers.