MTB Cross Country Marathon Training Advice

I am a 49 year old male (63 kg) and started recreational weekend mountain bike riding about a year and a half ago, essentially only riding up to 40 km once a week. Now that the bug has bitten, I have started structured training using TrainerRoad. After completing Sweet Spot Base Low Volume I & II, my W/kg has increased from 2.1 to 2.5 - a nice improvement, but not an impressive FTP at all. I am now busy with week 3 of Short Power Build Low Volume, feeling even stronger and looking forward to my next FTP test.

I would eventually like build up to participating (hopefully racing) in some MTB Cross Country Marathons. Cross Country marathons in my area are typically 60+ km with around 1500 to 2000m of climbing.

My question relates to training volume. While my current training volume seems adequate for shorter MTB rides/races, I am worried it may too low for longer Cross Country marathons.

Is my current Low Volume plan sufficient for Cross Country Marathon distances, or should I gradually start moving into a Mid or High volume plan as I get fitter? I am also considering starting to supplement my current Low Volume plan by adding a longer easy Sunday MTB ride of 3 to 4 hours.

Any thoughts and comments will be much appreciated.

For the most part, if you’re making gains in fitness, then the training that you’re doing is an appropriate prep for longer events. You’ll be averaging sub threshold over the race, so you can simply focus a lot on improving your FTP, so that the watts you can sustain are higher.

You could put extra emphasis on learning to ride at a higher percentage of your FTP for longer, which at the higher end makes a lot of sense. You mentioned that you were newer though, overall fitness gains will be far easier to achieve than focusing about exactly what shape your fitness curve is.

If you’re happy with the rate of improvement that you’re seeing on low volume, don’t think you need to move up. You can always add an extra weekend ride, or simply swap out one or more of the prescribed workouts for something similar but harder/longer. Doing a very long weekend ride is also a great option. If you’re feeling the bug to ramp up how much training you’re doing, you can certainly give mid volume a try. I wouldn’t jump up to high until you’ve ran through for quite a while on mid volume.

@Doug, TrainerRoad has helped me do exactly what you’re trying to do…at Low Volume. Keep up the hard efforts, stay well and you will be rewarded!

I’m a 44 year old mountain biker, and got back into training in March with: Sweet Spot Base I, Sustained Power Build, Cross Country Marathon. All were Low Volume due to time constraints. I’m very happy with the results at this level of stress (I started at estimated 170W / 2W/kg; now at estimated 273 / 3.5W/kg). 83kg down to 76kg along the way :grin:

Now that I’ve done all that and some marathon MTB rides, looking back I should have supplemented my low volume plan with extra outside rides and strength workouts. For future marathons your legs will feel good for the distance at the right pace as @roflsocks says, but staying strong for more than a couple of hours of wrestling your bike over rock gardens needs extra homework!

I preferred to stick with the assigned TR workouts so that I’d have the satisfaction of looking back on old workouts to see improvements. I wasn’t sure if the volume was going to be enough, but I wanted to be sure that I would finish what I started.


Thank you for the valuable feedback. The responses give a lot of comfort that I’m off to a good start on my current low volume plan. I will look to adding occasional outside rides for time in the saddle and to hone technical skills, but most importantly for fun.