Sex File: My boyfriend prefers a run to staying in bed with me

When one partner stops wanting sex, and the other doesn't, it inevitably causes feelings of rejection and frustration. Picture: iStock

My long-term boyfriend has become a fitness obsessive and the more he works out, the less energy he seems to have left for sex. He's 32 and we've been together for two years. I'm increasingly put out that he'd rather go for a run than stay in bed with me. He says exercise helps him handle stress but constant rejection is taking its toll. What can we do?

Exercise is generally good for sex. It gets your heart beating faster and increases blood flow in the body, which decreases the likelihood of erectile difficulties in men. 

Exercise is also good at helping to reduce stress because it triggers the release of "feel-good" endorphins — that "runner's high" people always talk about — and it also increases self-esteem and sexual stamina.

What your partner is doing isn't exercise, though. He appears to be battling extreme stress by channelling all his energy into a physically and mentally exhausting training regimen that boosts his dopamine levels but leaves him too exhausted to have sex.

There is strong scientific evidence to support the relationship between intensive exercise and decreased libido. 

In 2017, a University of North Carolina study involving 1,366 healthy men found an inverse relationship between male libido and the duration and intensity of endurance training. 

The harder and longer the men in the study trained, the less interested in sex they were, regardless of their age.

You don't explain why your partner is under so much stress, but sitting down and talking about what is going on should be your first step. Whether the issue is work, family or finances, it sounds as if he would really benefit from some psychological support.

You also need to explain how his behaviour is affecting you. When one partner stops wanting sex, and the other doesn't, it inevitably causes feelings of rejection and frustration. If those frustrations are not addressed, they will eventually undermine the relationship.

Although your question is "what can we do?", your partner is the one who needs to address this issue. 

Exercise is not the only way to manage stress and if his behaviour is impeding his ability to have a normal relationship with you, he needs to change it.

There are small things he could do to ensure you don't feel rejected. For example, you know he is too tired to have sex after he goes for a run but there is no reason you can't have sex beforehand. 

Even if he doesn't feel up to intercourse, cuddling, kissing and skin-to-skin contact can help to sustain intimacy and avoid those feelings of rejection.

As things stand, his exercise regime isn't just killing his libido; it is killing your relationship. I feel obliged to point out that that may be the intention. 

That he would rather go for a run every weekend morning than stay in bed with you suggests that part of his unhappiness stems from the relationship. Rather than deal with his doubts, perhaps he pulls on his trainers and leaves.

As I said, you two need to talk — but your partner also needs to be brutally honest about what he is really running from.

• Send your questions to [e-mail]