Training & Nutrition - Worth doing intervals on a SS?

I picked up an old steel Allez racing frame which my mechanic converted to a 45x17 single speed. As I've found that it fits me better than my "real" bike, I have been riding it more and the real bike less. I'm curious if there are any benefits to doing intervals on a SS rig. Obviously, unlike a geared bike all of the effort would have to be from spinning and not from mashing a tall gear.

A bit of background: I've been riding about a year and have logged about 1500 miles since I started. I rode some MTB before and have generally been active my whole life. I've tried almost every athletic sport, but I'm not really good at any. I seem to have a knack for climbing on the bike, which I guess comes from a hockey background, as I've played and weight-trained for that sport since before high school. When I was a bit younger I actually played an entire game once, just to see if I could do it. I used to be in stellar shape, but unfortunately I work in a job where I sit a lot and don't always have an opportunity to eat what I want to eat or be as active as I normally have been. As a consequence, though I've actually lost weight the last 2 years, it has been in a bad way and I'm less toned and more flab than I was before (I am 30 now, which I refuse to use as an excuse).

Anyway, the way the Allez is set up the bike cruises around 18mph on flat ground with a light wind with little (perceived) effort. In a flat out sprint I can get it up to 25 but I can't hold it long because of the cadence required. On my geared bike I can approach 29 but pushing a much taller gear, again, not for long.

Any thoughts? Should I just suck it up and ride my real bike to train on? Are there benefits to doing spinning intervals on one bike and then doing mashing intervals on another in the same week or am I training for two different things? I don't have time to ride as much as I want, so I want my training to be effective and not counterproductive. Should I just HTFU and STFU?

Roadies have been riding SS or, more usually, fixed for winter training since God was a boy. The idea is that you have to mash up hills and spin down them, the former for strength/power, the latter for suppleness/cadence. I have a 42/16 FG that I do some interval training on, because there's a two-mile loop round my neighbourhood that includes a couple of modest hills, which are nothing on my road bike but sufficiently challenging on the fixie. Half a dozen laps on the fixie gives me an interval session, keeps me in practice spinning at >150 rpm, and offers a simple way of checking on my fitness by recording my HR and times. (I'm too mean to invest in a power meter)

Riding SS rather than fixed rather diminishes the perceived benefits, because you can coast rather than having to learn to spin at high revs. So you'll get nothing from doing so that you wouldn't get from just sticking your geared bike into the 39/14 and leaving it there for the duration. Having said that, if you like riding the Allez better, ride it. And if it is a nicer ride than your "real" bike, think about maybe putting the gears back on? It isn't compulsory to ride carbon or aluminium...

......Riding SS rather than fixed rather diminishes the perceived benefits, because you can coast rather than having to learn to spin at high revs. So you'll get nothing from doing so that you wouldn't get from just sticking your geared bike into the 39/14 and leaving it there for the duration.......

I have to agree with you for the most part because I have a flip-flip rear wheel and the only time I setup for SS is when I lending the bike to someone else, and if I don't want the regimen of the fixed gear I would just ride one my geared bikes, and even if I just wanted to to mash up hills and spin down them I would still probably do it on my geared bike. When I ride my geared bikes I normally monitor my speed, my cadence, my perceived workload (no power either), and my heartrate, but when I ride the fixed gear I generally pretty much ignore my cadence and my speed and instead I concentrate on my perceived workload, my heartrate, and my route, because my cadence and my speed are pretty much dictated by the other three.

Instead, when I choose to practice spinning on my fixed gear I choose a fairly flat route and I concentrate my workout on my cadence and my heartrate, and when I am doing intervals on my fixed gear I choose a hillier course and I concentrate my workout on my on a heartrate and power output. To me spinning and interval training are just two completely different types of workouts that require different types of routes when you do them on a fixed gear, but both types of workouts are done quite easily on a fixed gear, but that's just me.....

I don't see the likelihood of getting the same level of workout on a SS vs a FG however, because as you said, coasting pretty much negates the advantage of the FG.

There are no training benefits, other than mental, to riding either SS or FG rather than geared. Riding SS will get you better at riding SS. Riding FG the same. Neither will get you better at riding a geared bike than riding a geared bike would, to the contrary. All that said, I enjoy riding SS. It's kind of cool to get so you can pull a paceline at 130 cadence, and to figure out how to climb long 10%+ grades with the same gearing. I don't think one benefits particularly from doing intervals on a SS or FG. Seems to kind of take the fun out of it for me. Just ride a mix of flats and hills. That's plenty of intervals. If you want to put gears back on the Allez, fine. Otherwise, just have fun. Get out on some group rides and challenge yourself. It's really not that much harder to keep up with geared bikes on a SS once you get used to it, as long as it's not a bunch of racers.

perfect. thanks.

BTW, my real bike is steel, too. putting gears back on the allez isn't an option - it was converted because the group was worn out.

Went out on a group ride today with a young fellow on a 70" SS. I either sat on his wheel or led him and encouraged him to accelerate on the gentle climbs and false flats. He got a heckuva workout. He was able to stay with the group because of having a freewheel and was destroyed by the end of the 55 mile ride. Good job.