We know that higher Testosterone levels mean better results from strength training (the higher the testosterone levels the more lean mass gained). In fact it’s so obvious that you're probably scrolling past this sentence right now.
But does strength training do anything for your Testosterone levels in itself?
A group of plucky young broscientists from Greece decided to find out…
The Experiment
They gathered 9 men with an average age of 23. Then for shits and giggles they decided to gather a bunch of what they described as "elderly" men with an average age of 69 (lol).
All these men were already lifting for at least 2-3 times a day for 9 months before the study which tbf is pretty impressive from the elderly group.
Then to show the younger participants what it’s like to be old (and to control other factors that can affect testosterone production yada yada) they asked them to abstain from alcohol and caffeine for 24 hours and wake up ridiculously early so they could arrive at the lab at 8am prompto to get to work.
Upon arriving they were made to do 6 exercises including the pec deck, lateral pull downs and the seated chest press. While this was going on the researchers ate their breakfast, barked orders and then occasionally took various blood levels.
They then asked the participants to come back another day under the same conditions to have their levels checked again but this time without having to do any of the weights. Basically getting them to act as their own control group. Why? Because fuck recruiting more than 17 people for a study thats why.
Apparently 2 of the participants from the elderly group didn't show up to the second control session (presumably having died of old age in-between sessions).
The Results Are In...
🥁 *Drum roll please* 🥁
Yes! Strength training does increase your testosterone levels... but only for about 15 minutes 🤦♀️.
Immediately after lifting the participants (both young and old) saw their Testosterone levels rise about 15-20%. 15 minutes later their testosterone started to drop towards baseline but still remained 5-10% higher than before they’d started.
Did they test beyond that 15 minutes to see if the rise would be sustained?
Hell no did they.
Presumably because they had to return the elderly participants to the local nursing home before they noticed they were missing.
It’s Not Just About Testosterone
The real story though is in human Growth Hormone which saw a massive rise post exercise (especially in the younger participants). Again this began to drop off after 15 minutes or so. 
Summary
So to summarise we now know that lifting heavy things makes your body produce more testosterone and growth hormone (a hella lot more). We also learnt that Greek scientists consider 69 to be elderly which kinda sucks for Bill Murray.
Unfortunately what we didn't learn was what the longer term effects on test and growth hormone are, because who can be assed running an experiment for more than 15 minutes 🤷.
✌️ peace