jimmuller 

This past spring I started experiencing tired neck muscles after riding maybe an hour or so. That's a new experience for me. Some background - I'm 72, i.e. personally Classic&Vintage. All of my bikes are C&V too. Until Covid hit I was commuting by bike 35 miles round trip most every day with no snow or ice on the roads and the temperature above 20degF. A typical one-way run might be 1hr20min. Until Covid hit I was riding maybe 8000 miles a year. Last year I rode indoors, eventually got bored with Zwift, still ride watching TV, but it's not the same is being on a real bike for 3, 4, even 5 hours.

Today's ride was with a high heat index and stiff winds, so I'm not surprised that some parts of me got worn out. But I felt it occasionally when I started riding this spring too. As I've gotten older I don't sleep as well or as much as I used too. I wonder it that's a contributor. My legs don't seem bothered.

So I'm just curious if anyone else has been though this. Maybe I just need to ride longer more often.
Cheers!

Iride01 

If you just got your first dose of riding in higher than normal for you temps, then anything might happen. I consider myself use to riding in heat and I think I do it smartly, but I have to work myself into it every year.

Hydration seems to be most important. If I loose too much body weight from sweating during a ride or even working in the yard all day, I'll be tired for the next few days, cramp up at night and find all sorts of muscle aches.

We had a spell of heat mid spring. I worked myself into riding in the heat and it was no issue. Then we had three or four weeks of unusually cool temps and now I'm starting all over getting use to the heat again. Thankfully I'm only in the 90° to 95°F temps instead of the 100° plus others are dealing with.

But if you also changed something up on your bike, then that might be a factor too. Going from wider to narrower bars helped me recently. But that was for wrist numbness on long rides. Though I might think wider hand spacing might also brace you too much letting your shoulder bear the brunt of the forces too much.

Lambkin55

I am a 68 year old male life-time bike rider. I get tight neck muscles every spring when I start picking up the mileage. As I have gotten older I find if I rotate between an upright bike and a drop-bar bike helps a lot. (The older I get the more time I spend on my up-right bike!!!)

canklecat

Yeah, same, for years. Twenty years ago six vertebrae were fractured in my neck, mid- and lower-back when a full size SUV ran a light at highway speed and t-boned my compact car. It had healed pretty well by 2016, but I was hit by a car again in 2018, this time during a bike ride, and never fully recovered from that injury.

I do a lot of home PT but my rides are usually limited to about 90 minutes before the neck discomfort sets in. Sometimes I can manage longer rides if I take plenty of rest breaks to stretch and massage my neck and shoulders. I've quit most longer group rides because I need more breaks than they have patience for. I have done several "metric" centuries and a few full 100 mile rides, but always solo so I don't need to adhere to anyone else's schedule or preference.

Last autumn I had to cut back on bike riding and switched to jogging to give the neck time to recover. Unfortunately it hasn't gotten better over the past several months. So I've cut back from almost daily bike rides to once or twice a week.

There are some good YouTube channels for physical therapy and bike fitting to accommodate ergonomic issues. And a lot of mediocre channels with unedited, poorly prepared videos that ramble on for 30 minutes when 3-5 minutes would do.
Check out:

• Bowflex channel (They aren't trying to sell Bowflex equipment, and many exercises involve no apparatus. They don't even seem to use tracking info on views to push ads into our browsers -- I never see Bowflex ads online.)
• Bike Fit Adviser -- best online by far. There are other bike fit channels with a few good videos, but none as consistently good and concise.
• Athlean-X (he rambles on longer than necessary but it's good info)