Does lifting actually raise your testosterone?
For a short while, yes. For your day-to-day baseline, barely. The better reason to train has nothing to do with a post-gym hormone spike.
A hard session gives you a real spike. Testosterone climbs in the 15 to 30 minutes after training and settles back within the hour.[1] Compound lifts through big muscle groups, decent volume, short rest, that is what drives it.
The part nobody sells you: that spike does very little to your resting, everyday level. Across the research, many training studies show no meaningful change in baseline testosterone at all, even as the same men get visibly stronger and add muscle.[1] The strength shows up either way.
The quieter payoff is circulation. An erection is a blood-flow event before it is anything else, and regular movement is one of the most consistent things research links with healthy erectile function. A systematic review of exercise studies in men with erectile dysfunction points the same way: regular aerobic training, kept up over months, was associated with better erectile function, with the clearest differences in the men who started furthest back.[2] Slow, unglamorous, and real.
STAMNR is not therapy or medical treatment, and it is not intended to cure, treat or diagnose any condition, including erectile dysfunction. It can sit alongside care from a GP or therapist.
If erection problems are new, persistent or worrying you, talk to a GP first and rule out physical causes. That check matters, and it is not a job an app can do.
And there is a ceiling. Push the volume too far without recovery and it turns on you: cortisol climbs, sleep suffers, and the whole system reads stressed rather than strong. More is not better. Consistent is better.
Training is one of the inputs you log each morning in STAMNR, as part of the last 24 hours. In the model behind your Firmness reading it is a slow builder: it compounds over weeks of showing up rather than spiking the number on the day you lift, and it carries most weight when your reading is low, which mirrors where the research saw movement matter most. Connect Apple Health and your workouts fill it in automatically. The reading is a readiness index, never a prediction about any given night.
- Kraemer WJ, Ratamess NA. Hormonal responses and adaptations to resistance exercise and training. Sports Med. 2005;35(4):339–361.
- Gerbild H, Larsen CM, Graugaard C, Areskoug Josefsson K. Physical activity to improve erectile function: a systematic review of intervention studies. Sex Med. 2018;6(2):75–89.
STAMNR turns a two minute daily log into one calm readiness reading, and shows you which of your own habits genuinely move it.
Get the appSTAMNR is not a medical device. It does not diagnose, treat or predict any condition.