Today’s question focuses mainly on the concept of training on a heavy bike and then racing on a lighter one

I have both a mountain bike and road bike. While I ride my road bike for triathlons, I know it takes more work when riding the mountain bike. My questions is would training on the mountain bike make the more efficient road bike easier when it comes to triathlon time?

Efficient Erin

Hi Erin,

That’s a good question. Quite a few people try this method of training for road races and triathlons – they get a heavy road bike or mountain bike to train on, then feel faster when they ride their nice bike.

Heck, I’ve even done hill repeats with cement-filled water bottles in my cages to make my bike heavier and harder to ride!

Unfortunately, it doesn’t make any difference!

Let me address this specifically: “I know it takes more work when riding the mountain bike.”

Yes, it takes more work to ride the mountain bike at 17mph than it does to ride the road bike at 17mph. But if you put that same amount of effort into riding your road bike, you’d be riding at ~ 20mph.

You have to think of it in terms of power output. Your body is going to use the same amount of power when riding either bike. The difference is, you’ll go slower on the mountain bike for a given power output. You’ll just feel faster on the road bike if you’ve been on the mountain bike lately.

Also, aside from not improving your fitness, you miss out on a very important training concept: specificity.

If you switch between bikes, your body won’t be as efficient at pedaling the road bike as it could be if you spent the majority of your time riding the road bike. So while mountain biking is great training for road racing, it doesn’t do much for triathlon training, and time on the mountain bike would simply take away from time better spent on the road bike.

Hope that clears things up!

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  1. Good response, Coach. Also, adding weight to a location on one of todays lightweight frames may cause it to become stressed in ways that it wasn’t designed to handle. I would suggest that you could increase the work performed if you perform at your normal speed and cadence while wearing a weighted exercise vest over your jersey. Multiple weight filled pouches on the vest will act as increased body mass and will require more effort to perform at your usual speed and distance over a given course. Take care not to over stress your back when stretched over your bike.

  2. Coach: I was thinking about the question this winter too, and while I had come to this same conclusion about power output, I still think there are advantages to training on a heavier bike during the winter (in my case a new cyclocross bike). The issue is that during the winter, you generally want to go slower from a safety perspective, especially if there is any kind of snow or ice on the ground. In that case, it helps to have a heavier bike, because you can generate the same power output but be going slower for safety reasons. I found that if I rode my road bike, to get the same workout, I had to go faster than I felt was safe. What do you think?

  3. @Jesse

    Definitely. Reduce your speed while keeping power output the same. There are many good reasons to ride a heavy, slow bike in the winter, and from a training perspective, that would probably be #1.

  4. If the same power output makes you go faster on a road bike then you will, of course, finish your training circuit faster.

    You will have had a shorter workout and burned fewer calories.

    Training on a mountain bike gives you a harder workout over the same distance, or as hard a workout over a shorter distance if the roadie increases the miles.

  5. @Wayne

    Yes indeed. That reminds me, that’s a good example of why you track training hours instead of miles.

  6. Also, by riding more slowly, one avoids windchill, which can really ruin a training ride.

    I have oversized tires slightly underinflated to help slow me down. I have a lighting system and car horns running off a heavy 5 amp sealed wet cell battery. More weight comes from a steel basket to hold my extra clothes.

    When it gets below freezing, I will switch to studded tires, which really slow me down because of the additional rolling weight.

    Heavy is good in the winter for training. Ride slower but keep up the cadence by dropping to a lower gear.

  7. @Mitch

    Thanks for sharing. Sounds like a seriously heavy bike set up, but helpful for many different reasons!

  8. Hi Coach Levi! Thanks for writing this article. I do have a question though somehow related. Like what Wayne1966 said, if one cycle faster on a road bike, one will end the workout faster thus leading to lesser total calories burnt.

    Looking at Dave Moulton’s model of how speed affects calories burnt, going at 15mph for 1 hour burns 465 calories. Yet this is higher still compared to one who cycles at 10 mph for 1 hour, or even 1.5 hours to match the distance.

    I’m wondering how does it compare since road bikes in general have an advantage – they go faster, thus higher speed = more wind resistance? Or versus one who is on a foldable bike, slower speed = lesser wind resistance and thus less of a workout compared. Assuming the power output is the same.

  9. @Adrian

    That’s an interesting question, and here’s the problem you run into – you’re using a bunch of estimates. And there are other factors, mainly body position, that affect wind resistance on an individual basis.

    You could spend hours running the numbers, and months or years conducting tests… or you could ride your bike. Which method do you think will put you closer to your goal?

  10. I expected more accurate and scientific answers here. The heavier the bike the more work the quads and other muscles are required to do hence better exercise. The key is to increase the pedal speed rpms to maintain both target wattage and heart rate for desired workout effects … Cardio vs fat burn vs strength vs on heavier bikes significantly improves performance on lighter bikes.

  11. Hello, I am a competitive cyclist in Nairobi Kenya. I was told to rid off my heavy mountain bike in favor for my light steel road bike. You’ve mentioned a key aspect that I too discovered (Specificity, because most pros in Kenya train hard on the road bikes they’ll use in a race. I do not know if I’m special or a nutcase but I discovered that mtb training makes me strong hence better performance on my road bike only if I train days before the race day on my road bike. I’m not a pro but I love the experiences of different bikes and excelling as much as possible on either of them. But the key factor is specificity, train on one bike for 5 to 7 days. The first 2 days are for familiarity, days 3, 4 and 5 are for achieving maximum cadence, lastly days 6 and 7 are for maintaining that perfection. Its not recommended but I feel I should say this for the sake of those who feel the itch of being cycling monsters on any bike (if possible)

  12. What if I put extra weight on my regular training bike, such as, like you said in your article, cement-filled water bottles?
    Would it strengthen my legs and make me go faster on climbs/flats after I take it off?

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