[abarro81]

You don't get big bulky legs from just cycling, you have to do a lot of hard, short power building efforts to build leg muscles.

In my experience this varies person to person. I have a friend who cycles in and out of biking lots (pun not intended), and swears it doesn't make his legs bigger. I've had 2 periods of biking lots (for commuting) in my life and in both cases it made my legs bigger.

Optimum leg size, obviously, depends on what you're doing and will no doubt be bigger for compy jumps and prow mauling than for onsighting 40m fingery routes.

[SA Chris]

prow mauling, great phrase

[MischaHY]

I would tend to agree with Barrows that there is a strong genetic component at play. Whenever I do a significant volume of MTB or steep approaches I do put on a kilo or two of muscle mass.

However I think it's important to look at these things in context and consider why this would even be considered an issue. The easiest way to consider it is that your body (genetics obviously affecting the extent) will respond to the load you put on it. With this in mind it seems an odd goal to want to do a fair amount of cardio if you don't want to see improvements - which sometimes does mean adding a moderate amount of mass to sustain your efforts.

Its also very common to see climbers with varying degrees of knee injuries from heel hooking or similar torsional loading which likely could have been prevented if they had a more robust level of conditioning in the legs. Not being able to hold a heelhook with the muscles engaged is a common way of damaging the soft tissues around the knee in my experience.

If you're keen to avoid putting on mass and also generally avoid a high impact on your climbing then it's best to avoid the HIIT style cardio as this has a higher impact due to the increased intensity. Instead opting for low intensity steady state cardio i.e. long trail runs at a moderate pace and sustained low heart rate would be a better choice.

All that being said I would say it's important to recognise that a higher volume of cardio is always going to have an impact on your climbing ability simply by eating into your available recovery capacity so if you're looking to make climbing gains it's definitely a good idea to dial back the cardio volume to allow for better recovery.

Hope this adds value :-)

[SA Chris]

I'd like to hear from the OP how much running they were doing before that resulted in losing considerable leg muscle mass, and if it was offset by any weight gain elsewhere, or did they cut calorie intake accordingly.

[T_B]

If I had Mo Farah’s legs I reckon I’d be all over Font 8b.

[Paul B]

In my experience this varies person to person. I have a friend who cycles in and out of biking lots (pun not intended), and swears it doesn't make his legs bigger. I've had 2 periods of biking lots (for commuting) in my life and in both cases it made my legs bigger.

I'm hardly the type that puts on muscle easily but my legs are now bigger to the point my jeans* are getting a bit tight.

*I have to buy child's Levis that are designed for 12-15yr olds.

[duncan]

I would tend to agree with Barrows that there is a strong genetic component at play. Whenever I do a significant volume of MTB or steep approaches I do put on a kilo or two of muscle mass.

This is me. I really should have been a mountaineer. I put on leg muscle, especially calf muscle, just thinking about walking up hills, I'm almost identical to my Dad in this respect and we were both handy middle-distance runners in our youth. Plenty of science to support this anecdote.

All that being said I would say it's important to recognise that a higher volume of cardio is always going to have an impact on your climbing ability simply by eating into your available recovery capacity so if you're looking to make climbing gains it's definitely a good idea to dial back the cardio volume to allow for better recovery.

Particularly if you are using your arms for this: you're unlikely to recover optimally from climbing training if you're working your arms sufficiently to have a meaningful cardio. effect.

My question to the OP is what do you hope to gain from doing 'cardio.'?

[Stabbsy]

If I had Mo Farah’s legs I reckon I’d be all over Font 8b.

You’d find it harder to stay upright in a moderate to strong breeze though Tom. And you’d have to get someone else to carry your pads.

[User deactivated.]

Whenever I do a significant volume of MTB or steep approaches I do put on a kilo or two of muscle mass.

2kg is a lot of muscle! I'd bet money that this is predominantly increased glycogen and water retention within the muscle due to it being used, rather than actual muscle tissue. I rarely deadlift anymore, but when I do, like clockwork, I will be at least 1kg heavier the next day and it will gradually drop off over the next week. I definitely didn't gain 1kg of muscle from 1 training session!

The distinction between glycogen/water retention and muscle mass probably doesn't matter for climbing performance - extra weight without the increased sport specific strength is not going to help, but upon cessation of the MTB and steep approaches the gained weight should disappear fairly quickly? If it were actual muscle tissue it would stick around much longer.

[AMorris]

You don't get big bulky legs from just cycling, you have to do a lot of hard, short power building efforts to build leg muscles.

In my experience this varies person to person. I have a friend who cycles in and out of biking lots (pun not intended), and swears it doesn't make his legs bigger. I've had 2 periods of biking lots (for commuting) in my life and in both cases it made my legs bigger.

Optimum leg size, obviously, depends on what you're doing and will no doubt be bigger for compy jumps and prow mauling than for onsighting 40m fingery routes.

A valid point, it's likely there is a 'genetic'* element to this (as there often is). I used the term 'bulky' for a reason. Your legs may have got bigger, but would you consider them bulky? I find it very hard to believe that the majority of people respond so drastically from commuting that they put on significant amounts of muscle mass in their legs. The implication behind the line of reasoning I was challenging was "if you cycle, you will end up with bulky legs which will be detrimental to climbing performance", which is simply untrue. Pro cyclists (sprinters and puncheurs particularly) have bulky legs because they focus a lot of their training in the top power zones. I would say that it is far within the realms of possibility to use cycling as a means to improve cardio without gaining muscle mass in the legs, particularly if you stick to zones 1-3.

* I put genetic in inverted commas, because nowadays it is used as a catch all term meaning "physiological variation not easily explained". It is not so easy to actually establish whether there are genetic markers associated with this kind of phenomenon, in most cases. Much of the time this is quickly followed by people discussing how they, as kids/adolescents, pursued an activity which specifically taxed that system, meaning it could just as easily be argued to be an acquired epigenetic trait.

[MischaHY]

Whenever I do a significant volume of MTB or steep approaches I do put on a kilo or two of muscle mass.

2kg is a lot of muscle! I'd bet money that this is predominantly increased glycogen and water retention within the muscle due to it being used, rather than actual muscle tissue. I rarely deadlift anymore, but when I do, like clockwork, I will be at least 1kg heavier the next day and it will gradually drop off over the next week. I definitely didn't gain 1kg of muscle from 1 training session!

The distinction between glycogen/water retention and muscle mass probably doesn't matter for climbing performance - extra weight without the increased sport specific strength is not going to help, but upon cessation of the MTB and steep approaches the gained weight should disappear fairly quickly? If it were actual muscle tissue it would stick around much longer.

Nah it's accompanied by clear shift in mass and definition on legs and backside. Nice for the girly but annoying for climbing!

When I stopped mountain biking regularly I initially dropped noticeable mass but it was quickly replaced by back muscle instead.
I've a similar build to you i.e. 173 and 78-79kg. I add mass easily to my legs but not to my upper body, it's quite bizarre.

[boxmonkey]

Really interesting to see the debate.

Caving is a good one as I used to do a lot of underground stuff before realising I wanted to climb up not under a crag.

I thought cycling would definitely build leg muscle so it’s interesting to reassess that.

I figured short repeated sprints, like HIIT,  would be good for ensuring good cardiovascular health without building big muscles that endurance running might produce, so it’s interesting to see the points of view on that.

Oh and the points on heel hooking - definitely - this is something I’ve wondered about. I always walk away from sessioning problems with heels feeling like I almost popped a knee and hamstrings feeling wrecked. I might give that some more thought.

Thanks guys.

[edshakey]

Bit confused how many times high intensity is being suggested over low.
Comparing Mo Farah to Usain Bolt, it's pretty clear who has the legs we're looking for! Obviously Bolt also may gain some of that muscle in the gym, but there's surely no way running long distances makes your legs even bigger. Middle and long distance athletes routinely run 100/120 mile weeks, that volume doesn't seem to cause them to have huge legs.
The same argument would apply to track vs road cyclists. If we're looking to boil it down to as simple as possible: choose a sport where people don't have big legs, then train like them 

I will add something that may appear contradictory but I believe isn't - I've been doing lots of hill + distance running this year and I've noticed my thighs have grown from already reasonably large (in comparison to total body mass) to even larger. I get the impression that's due to the hills, which feel like more of a high intensity work out than just long distances, but it does surprise me to see people like Finlay Wild who don't have noticeably large thighs. Maybe that's just due to lower body fat percentage making him look slim all round? There is also the genetic/unexplained variation which may well be very consequential as to what people choose for slim leg cardio. Maybe I'm naturally quick to build muscle mass from anything that works my legs, so if I really wanted to avoid this, I'd need to go for one of these other options. But I like the hills, so not going to stop!

[SA Chris]

Kilian Jornet doesn't either, must be genetic predisposition you are (un)lucky!

[Wellsy]

I suspect there's a diet element too

[User deactivated.]

I suspect there's a diet element too

This. You don't gain weight (beyond normal fluctuations) without eating in an energy surplus. Where else can the weight come from?

Do heavy squats and deadlifts twice a week while eating at maintenance and, if you're relatively untrained, you will gain muscle and lose fat at the same time whilst remaining at a similar weight. This is called recomping in fitness circles.

Nah it's accompanied by clear shift in mass and definition on legs and backside. Nice for the girly but annoying for climbing!

When I stopped mountain biking regularly I initially dropped noticeable mass but it was quickly replaced by back muscle instead.

Increased glycogen and water retention would still look like added mass and definition. I've got a couple of mates who compete in bodybuilding and after dieting down for a competition they initially look flat, but 1 day of slamming carbs to peak for the show and they will gain as much as 5kg! The muscles fill out while still looking chiseled and I'm told that getting this process right can be the difference between first and last place.

Muscle tissue gain isn't quick. Even an 18 year old who is a complete newbie couldn't expect to gain much more than 2kg of muscle in 3 months after following a strict weightlifting routine and eating in a calorie surplus (based on most research showing muscle gain in the first year of training tops out around 10kg for top tier genetics, and much less in subsequent years).

[cheque]

choose a sport where people don't have big legs, then train like them

I choose climbing.

[tomtom]

Doesn’t this all depend upon your physiological starting point?

Eg. If you’ve never really done any cycling/running in your youth/the past then you are going to develop new muscle ability to account for that - and hence some bulk.. (non?). Whereas if as a youth/young adult you did loads of running/cycling/football/rugby (whatever) then started climbing… if you go back to the other sports again you already have a base of muscle mass so growth won’t seem so great.

Don’t forget that Mo and Bradley have stick thin upper bodies too - so in power to weight terms they don’t need big legs to move them.

[webbo]

In regard to Wiggins as a track rider he was heavier and carried more muscle. When he targeted the tour he lost weight including a significant amount of upper body muscle.

[Fultonius]

And all of those guys are on pretty extreme diets / training plans/ supplements / unbanned drugs (TUEs) etc....   Maybe not a great reference! 

[MischaHY]

I suspect there's a diet element too

This. You don't gain weight (beyond normal fluctuations) without eating in an energy surplus. Where else can the weight come from?

Do heavy squats and deadlifts twice a week while eating at maintenance and, if you're relatively untrained, you will gain muscle and lose fat at the same time whilst remaining at a similar weight. This is called recomping in fitness circles.

Nah it's accompanied by clear shift in mass and definition on legs and backside. Nice for the girly but annoying for climbing!

When I stopped mountain biking regularly I initially dropped noticeable mass but it was quickly replaced by back muscle instead.

Increased glycogen and water retention would still look like added mass and definition. I've got a couple of mates who compete in bodybuilding and after dieting down for a competition they initially look flat, but 1 day of slamming carbs to peak for the show and they will gain as much as 5kg! The muscles fill out while still looking chiseled and I'm told that getting this process right can be the difference between first and last place.

Muscle tissue gain isn't quick. Even an 18 year old who is a complete newbie couldn't expect to gain much more than 2kg of muscle in 3 months after following a strict weightlifting routine and eating in a calorie surplus (based on most research showing muscle gain in the first year of training tops out around 10kg for top tier genetics, and much less in subsequent years).

Yes sorry I didn't specify a time frame. For context I was talking from a stand point of 5 years of consistent regular loading in that specific sport type, and then subsequently another 5 years of much reduced loading in that sport type. The shift in mass that I observed took at least 2 years to happen because I was still regularly loading the legs in climbing and mountaineering.

I agree with much of what you're saying and think your thinking is  on point.

I think the real thing to keep this thread on track is just to really remember how individual we are and how individuality will affect your body composition and muscle mass. It's really so nuanced and hard to make even vaguely clear statements about the potential impact of a change in loading on an individual without really going quite deep into their training history and historical body composition.

Having recently dropped significant weight for the first time in my life I also recognise why this such a discussed topic. After reintroducing significant carbs I'm around 3-4kg lighter but literally gained a full font grade in flash. It's insane.

[webbo]

And all of those guys are on pretty extreme diets / training plans/ supplements / unbanned drugs (TUEs) etc....   Maybe not a great reference!

And climbers aren’t doing those things. Well maybe not unbanned drugs

[AMorris]

And all of those guys are on pretty extreme diets / training plans/ supplements / unbanned drugs (TUEs) etc....   Maybe not a great reference!

I would say the opposite to be honest. If they can dedicate their every waking moment to building themselves into the ideal specimen of high-performance Grand Tour GC contender, yet still not end up with the massive legs which climbers seem to be terrified of receiving in the mail with their commuting bike, then I would say that means there is more to building leg mass than just cycling for aerobic gaenz.

There is a massive difference between cycling in the top power zones (thus building power and muscle) and cycling in the lower power zones for cardio. This is the difference between being able to hold a steady pace for hours, and a full-on sprint which you can only sustain for up to 30 seconds.

Don't anyone take my word for any of this, it's all out there for perusal. I am just regurgitating what I have read and personally experienced.

[webbo]

When I had my shoulder repaired I had 3 months off climbing and riding my bike outside. I used my turbo for and hour one day the walked between 8 and 15 miles the next day. I usually had one rest day a week. My thighs got bigger over this period. Prior to my operation I would do a couple of interval sessions and one 60 to 80 mile plus ride and climb 3 times.
However no matter what I do my calves never get any bigger and my left one is significantly smaller than the right since I ruptured my Achilles but not noticeably weaker.

[Wellsy]

If you stay in a calorie deficit/neutral you can do any kind of cycling you want, you won't put on overall mass, though you may develop increased lean mass and reduce body fat percentage. Probably in your thighs area, rather than calves. Your calves will never change.

I dunno if looking at top end cyclists is really useful for the impact of cycling as purely an accessory for an amateur climber. They are combining high levels of cycling with very specific diets and, yes, drug use in order to create a specific adaptation. That's not what the OP would be doing.