After a several months of constant effort but little improvement in capability, I've come to the conclusion that I could probably do with some interval work. Problem being that a google search will turn up a PILE of variations on actually doing intervals.

I'm 62, been biking about 20 months and my ride averages (20-40 miles, 600-800 feet climbing, 5 times a week) have been hovering right at the same 15.5-16.5 mph for months without change. I've got a Garmin and keep a spreadsheet of all the data on my rides and it is pretty obvious that my condition is static.

Comments? Links to interval descriptions that worked for you?

Here is a link to a comprehensive list. https://www.bikeforums.net/showthread...ut-recipe-book

I do not see a problem with your performance or speed. The key to selecting a workout session is to know the goal. It seems like you need a new goal or challenge versus an interval routine. If you think that going hard will break the routine, it will. IMO, going hard without an underlying goal will grow old quickly.

Here is another thought. If your goal is to increase your average speed, they focus on applying more energy over those sections of the route that we know are harder - climbing and windy sections. Raise your effort in the tougher sections and maintain normal speed in the easier ones. That is a form of interval training. That will work.

In my personal experience, all the interval sessions that I have done that were supporting a specific goal worked. And I have done most of them.

When you start cycling you have to get bike fit. Ride enough and that comes quickly and the muscles have built up- the ride position adapts and pesonal fitness comes in. takes about 3 to 6 months for most of us.

Next stage does not come in for a couple of years- and even then it is gradual. The big step came at the beginning.

Started riding 20 years ago and on some pretty aggressive offroad hills. I still have a marker hill for my performance and initially it took me 3 years to conquer it consistently. That came about by Getting bike fit initially- Getting personal fitness in and also getting the right bike for those hills. I still have that as a marker hill and I know I am doing OK if I can ride it. Know I am doing better if I do it in middle ring and the last stage of being really fit is when I do it just behind the fit bloke that is charging up the hill.

Interval training may help on Sprint speed but sounds like what you WANT is more overral speed. 15 to 16.5 MPH is not that bad but if you want to increase it- Then do as Hermes suggested- put more effort into the harder bits of the ride. Take the slight uphill section and stay in the same gear- keep the same cadence and push when it gets hard. I do that on a 400yard 4-5% slope we have on one of our rides. Start it at say 14mph and finish it at 14mph. By the end my legs are pumping up and the lungs are working.

Or up the milage to 40 to 60 and try to keep the same average

Or join the local club and go with the Group that are just above yout comfort zone.

All will work- but if I could manage 16.5 mph over a 40 miler on our hilly road rides- I would be ecstatic. Although saying that- My usual speed on a metric-100 kms or 65 miles- is 16mph. I think that is fast enough for me.

Listen to Hermes, he knows.

Probably I got spoiled by the huge improvements in ability that happened through last year and expected that further improvements, if not on quite the same scale, would continue. This plateau took me by surprise, figured I would be in the low 20's by now. All well, it seems that nothing ends up as easy as it first looked.

But Hermes is right, the way to accomplish anything is to set goals.

I think you need more time to recover. Try 3 times a week, increase mileage to 55 to 60, live in the big ring with low cadence for about a month. Put it into the lowest gear and stay anywhere between 14 to 18 mph all the time. Try doing the first 20 to 30 miles non-stop each trip. After 3 weeks of this i am getting marked increases on my overall mph(includes all stop signs/red lights). Went from 16.5 to 18.4 over my regular 53 miles. I am 66 years old. Love the wind.