Peri-menopausal female with diagnosed osteopenia here… I took 5 months off from lifting to focus on cycling and saw about a 20W FTP increase to ~3.5W/kg. Have decided I really need to get back into the gym. The problem is that the fatigue from lifting really persists for about 2 days on the bike. As in even endurance pace feels hard. By day 4-5 my legs feel good again. So it seems to me I really just can’t do both. I would say most would consider me “strong” - at least for a cyclist. At 60kg I exceed level 3 here. At the end of the day I am a recreational cyclist and I feel like health has to take priority. But maybe I don’t really need to lift as heavy as I do? I guess I don’t know the literature well enough to know how “heavy” I need to lift for bone density - but all I hear on female focused menopause podcasts is the importance of lifting HEAVY. Any other women been down this road and found a way to successfully do both? I lost about 10W due to illness that took me down for 4 weeks so I’d love not to completely lose all 20W I gained over the last 5 months.
Male here, sorry, I figured out I had to compromise. Leg days lifting was not going to make for productive riding days later in the week. I would still ride, but no suicidal group rides post lifting. But it’s hard to tell people to not lift because I rode with a guy that was a power lifter (not a HUGE guy though) and even though he was large in the wind, he had the muscle to actually pull that mass through some brutal headwinds. Best option was to tuck in behind him and get that glorious draft to pull you along. But he didn’t ride all that often, and I think it was him trying to fit it all into a week.
I have ridden with many women who were lifting, but it never came up in conversation, like men I rode with (except for some whining about be dropped because of a previous leg day 
)
Compromise… If you want to heavy lift, you can’t rip long distances on the bike.
Maybe lower weight and more reps, and spacing riding after a rest day? Personally, I ended up compromising by lifting for upper body development/toning, and forgoing doing anything with the legs. Sure I would sometimes have issues with shoulders and arms riding, but aiming the bike is a lot easier than driving the pedals continuously. So I thing I got a pretty good workout doing that compromise. YMMV. Good luck finding your balance.
What lifting are you doing:
What movements?
What weight (% of 1RM or % bodyweight) for how many reps and how many sets - per day and per week? How close to failure are you going?
Hard to give any sort of advice until we have that information.
ETA: people tend to stress HEAVY because they’re battling against 30 years of “toning” and pink dumbbells. It’s all relative.
Heavy lifting and endurance exercise are antagonistic. There’s no magic formula; just pick what matters most to you.
https://www.trainerroad.com/blog/strength-training-maintenance-for-cyclists/
Some fairly decent advice in this article. I find I suffer exactly the same when I concentrate on gym work. I’ve found that focusing on strength for about three to four months over the winter helps me get more robust but inevitably I do lose a few watts of my FTP. As the focus shifts to building up on the bike, I start to drop the gym workouts as in total number and weight lifted, I usually end up in summer going to the gym once a week to squat/deadlift and then maybe a couple of easier sessions at home with a focus on core/kettlebells/dumbells for maintenance.
Everyone is different and finding the balance is highly individual, I find strength training very tiring just on it’s own, yet I can ride all day/ multiday trips even and be reasonably fresh, throw in a gym session though and my legs hate me! I absolutely see the value in strength work though for the life benefits it bestows on me, so I’m happy to gift a few watts of FTP for that.
The persistent pain from lifting is only temporary. After a few weeks you’ll be able to cycle as (almost) normal. Your FTP won’t decrease from a few weeks slightly less training and if it did it is much easier to regain than gain
If you exceed level 3 as a recreational cyclists, I’d say you’re on top of the game atm, so don’t stress too much. 
You can hit the weights with sorta maintenance mode, balancing between workouts for 1) big weight low reps low sets for neuromuscular power on another day and 2) low weight, medium long reps, medium sets for overall joints and muscle contraction maintenance. As you have good output in those key movements, it’s a question of maintenance really.
So focus on doing as little as possible, not as much as possible, to keep that level 3 output. Doing just short but sufficient warmup reps - or treadmill walk-run, wink wink - and staying in that 4-5 reps level on high power workouts, should tax your body less and give quite reasonable recovery for those cycling workout days.
You can also add bone density by doing light running workouts if you prefer. And if you do gravel cycling, then the road buzz from the saddle and handlebars gives much more activation for bones than say heavy road cycling only.
It may be that your background / hormonal status is having an impact. If so, chat to your physician.
However, this is a problem that lots of people encounter and I have fought with for most of my time cycling as I like to lift regularly for long-term health reasons.
The things you might want to try that have helped me:
- Reducing volume but maintaining intensity - heavy 5x3s rather than 5x5s.
- Keep it super simple by reducing the number of different exercises / do them both days (eg on deadlift day I squat for volume, and on squat day I deadlift for volume) - this has a huge impact on doms for me - doing something once a week or less is a recipe to be done for.
- Hard days hard - lift in the evening after intervals at the end of a micro block, then take a rest day (I run 3on1off, so lift on the last day).
- Eat more. Yes, protein, but also good carbs.
- Periodise your lifting. Lift heavier and more regularly in your offseason when you are not doing vo2 work. Don’t stop in the race season, but just see how minimalist you can be.
- Keep 1-2 reps in reserve unless going to failure on non-leg muscles (aka abiding by minimalist trg methodology). Going to failure had disproportionate impact on soreness for me.
- Don’t miss a lifting day. If I found myself short on time for the double, I’d just lift. I can always make the time up on the bike.
These have helped me as an about average masters bloke (c 1.75xbw squat and 5wkg) this year. Hope some might be helpful.
I’m trying to split leg day into two days (thinking maybe lower volume would help). I do 1-2 warm up sets, usually 50%x10, 80% x3-4, then 1 set to 1-2 RIR. I weigh ~130.
Day 1 - Hack squat - this is a new movement for me, don’t know 1 RM, did 205x8 last time, that may have been 2-3 RIR, Hex bar DL - 165x6 - 1 RM is likely 200ish, cable step ups 100lbs x 10R/L - same 2-3 RIR
5 days later…
Day 2 - Hip thrust - 225x6 (this is low for me but since it has been 5 months the BB hurts my hips even with a pad), ham curl seated - 70x8 - this was to failure, banded glute extentions (like a back extension but with shorter ROM) - BW + Band - high reps, maybe 15-20 - burner kind of movement.
I get you on the pink dumbbell thing! And I guess this is my fundamental question. I guess I just need to go to pubmed and get an idea of the weights used in these studies… I think I perhaps am exceeding the weights of what has been studied in many of these bone density studies, but I don’t know. Maybe those women are deadlifting 200 lbs for reps! Who knows
That is interesting about the vibration… think MTBing is the same? There aren’t really gravel roads near me. I’d never even thought of that. Is that your hypothesis or have I missed this in the literature?
After 5 months off I was shocked how little strength I lost to be honest. And your suggestion of high weight low reps was my strategy based on some lifting podcasts I’ve been listening to about fatigue post lifting coming mainly from volume.
Yeah or you don’t need to ride a bike as hard as you do. If health takes priority, it’s more important to address your osteopenia over your ftp? I say this somewhat jokingly, but also serious. You haven’t been diagnosed w low FTP yet, have you?
I’ve diagnosed myself with low FTP 
I come from a very heavy weight lifting background and more into cycling the last year. While I prioritize cycling, I won’t let go of the lifting. I lift hard twice a week, one day primarily lower and the other primarily upper. I do 2 high intensity sessions in my cycling training blocks. I usually aim to do my HIIT on Monday/Tuesday, and my heavy lower body workout Tuesday afternoon. That way I’m not impacted for my Friday HIIT session or my weekend long ride.
Once you’re up to speed weight lifting, I generally find workouts in high rep ranges (12-15) create much more DOMS than low reps (3-6).
While strength training is importsnt for everyone, particularly as we age, I would have considered higher impact exercises the primary benefit to bone density related issues (walking, running, plyo’s), etc.
You know good ol’ bro science that is… Just gut feeling doing looong gravel rides and fingers and wrists taking the beating. But I think mtb too for sure. But no science paper about it.
Lucky you for staying strong after 5 months off, me at almost 60 yo so puzzled how much strength is lost like after 5 weeks. 
Do you eat high protein? I eat a TON and think that must have something to do with it. I’m 47 and female, so biology certainly isn’t on my side.
At my next DEXA I’ll ask for a forearm scan - test your theory 
I’m trying to stay in a 1,5g/kg per day, metric ton is too much for me I think… 
But it keeps me hovering around that level 2 that I’m targeting to keep with my 74kg bw. Well military press no go tbo, but I don’t mind underperforming that, as I’m pretty sure (bro science warning) any groupride or race that I ever entered was not the case of military press performance.
That all seems perfectly reasonable. Good movements, good sets/reps schemes and the volume’s sensible.
So, my question would be - is it mostly neural fatigue or mostly muscular soreness?
In the absence of anything else, my guess would be that it’s the latter, both because you’re back in the gym after time off and also because you’re doing at least one new movement. Keep going, increase load/reps very slowly, and all should be well.
But I could be talking nonsense.
This is basically the exact set of things that has helped me. Number 3 seemed to be the biggest lever for me. I accumulate too much fatigue spreading intensity out and it is easier to push through all the hard stuff on one day.
Keeping 1-2 reps in reserve and lifting weights the same day but after cycling interval sessions is what I was doing.
Though I’ve taken a break from lifting heavy at the moment in favour of some other types of weight bearing exercise (bit of running, football etc).
I definitely agree that health is wealth and too much cycling can have poor outcomes in other areas if we neglect them (bone density, imbalances etc)
That has never been the case for me. During a time when I focused on weight lifting I was always sore for at least 3-4 days just like OP. Fast twitch muscle fibers are fragile and takes far longer to recover than slow twitch fibers.