I am in week 2 of a 12 week plan to do squats twice per week. Nothing super heavy at this point.

Squats make my legs VERY sore. The soreness can last for 3 to 4 days. I am 6' 4" and race at ~173 lbs. I have decent cat 4 endurance, but need a lot more power to stay in the same zip code as the sprinters 200 meters from the finish. I am 34 and just started seriously training (after a 10 year break) 17 months ago. I am on my bike 10-12 hours per week.

Do you think squats have made a big difference in your race results or the race results of people you know?

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Yeah, they do make your legs sore, don't they? IME better technique is the fastest way to get faster. You could try a coach. That's followed by sprinting specific drills and intervals. But not to say that now isn't a good time to think about getting stronger. You might want to look at this: https://www.sportsci.org/jour/04/cdp.doc

You are sore most of the week. Your body is telling you something.

Cut your weight in half.

Squats are king. But not so much in cycling. Find a training program for racers.

I can understand your focus on developing power. As I am a sprinter I firmly believe in weight training for cycling. I finished crit season this year at 199 pounds (I am 5'11") but raced between 199 - 206 this year. Though I cannot attack true climbers while climbing I can can hold my own with them it just hurts a little more. I owe much of this to my continual weight training throughout the race season. I work with a trainer who has never ridden but is the best I have ever seen.
My advice would be not to focus solely on squats as there are many other exercises that will help develop the entire leg. I have gone away from my traditional leg routine (heavy squats, deadlifts, leg press, extensions) to a much more functional type weight program. The results seem to be coming. For an example here is yesterday's session with my trainer:
Today's workout in this order (the goal was to pre-exhaust the core and quads):
Situps on a decline bench with 20lb medicine ball - 2 sets to failure
Hyperextensions with 4kg kettleball x 20 reps then hold in hyperextension and twist back and forth at the core for 20 reps x 2 sets
Kettleball thrusts x 3 sets
Walking lunges x 2 sets
Side walking lunges x 2 sets
Leg extensions x 3 sets
Standing lunges with carpet slider - first 2 sets the lunge went to the side then back behind your alternate leg, second 2 sets the lunge went out to the side then back
Single Leg Leg Press x 4 sets
Single Leg Bench Squats with kettleball x 3 sets
Single Leg Lunges with one leg up on a bench and holding kettleball x 2 sets
Calf Raises x 3 sets
Core work on Bosu ball while holding medicine ball
Superman hold on Bosu ball for 30 seconds x 2 sets

I will be sore for several days and I did not do any crazy weight (heaviest I went was on leg press - 4-45 pound plates per side using one leg) it is the order in which I had to do the exercises that made a huge impact.

Even though the maximum force exerted by the legs in a full out sprint is less than 80 lbs. You must be severely limited in leg strength to have trouble producing this amount of force.

I don't quite understand what you are saying please clarify. I can tell you if I am sprinting pushing a 53x11 at 40+ mph that there is more than 80 pounds of force going into my pedals.

How are you measuring how much force is going onto your pedals? It's easy to calculate the force required to produce a certain power at a certain rpm (after all power is just force times velocity) and this has been done numerous times. The results show that for sprint powers around 1500W and cadences of around 110 rpm (because I don't know the exact values), the resultant force is around 80 lbs.

O.K. I'll do it again. 1500 W; 110 rpm = 2 m/s; => 750 N = 168 lbf for 2 legs = 84 lbf/leg

Understood now in addressing your original statement that "you must be severely limited in leg strength to have producing this amount of force" - this would then make the assumption that all people who are capable of producing this amount of force are equal wouldn't it? The greater strength you have the more efficient you are at reproducing 80 pounds of force continually (i.e. while sprinting) thereby making you faster.
BTW sprint cadence is well in excess of 110 rpm - probably more in the 130-150 range.

Or it could mean that if all people who are capable of producing this force are not equal, then the inequality must be caused by some other factor; as in fact it is. The limiter to performance is not strength but the ability to produce power over the intended period of time. Further, this ability to produce force over time is not coupled to or limited by maximal force (strength) so developing strength does not increase the sustained power.
Yes, but that would only lower the force required for the given power reinforcing the argument that strength is not a limiter. I deliberately chose a low cadence as a worst case type of example.

I agree with your points but as I said earlier strength training increases your efficiency in creating this power countering your statement "The limiter to performance is not strength but the ability to produce power over the intended period of time"

I realize that this is a debate that goes on between people all the time and I know that we can't settle it here so to pose a question regarding this issue in particular; do you weight train? what kind of racer are you (i.e. sprinter, climber, etc)? how would you improve the op's dilemma?

How does what I do or whether I race or even ride have any bearing on how the body produces power to move a bicycle forward? Without a much more thorough understanding of the OP's situation, I would never make any recommendations. I will say that in almost every case I've seen, the inability to keep up in the final few hundred meters of a race is due to lack of aerobic power. How one goes about increasing aerobic power has been discussed at length, but generally comes down to riding so that the aerobic system is stressed to the point that adaptations occur resulting in increased aerobic capacity.

As I never answered th op's original question and asgelle and I seem to have a difference of opinion I will say, based on my honest opinion, experience and results that weight training and more specifically leg training have absolutely made a difference for me. I will agree with asgelle that weights are not a substitution for hardwork on the bike just aids in development.

The only reason I ask is to see if your statements are based on experience or education.
Many people used tried and true methods that work for them and may not necessarily be accepted by the masses as the norm. For example Mike Metzner's bodybuilding approach - not accepted by many but it worked for him.

Lifting works for me, always has, and my statements are based on my experience and successes. If my lifting allows me to hit that instantaneous 2000w that gives me the jump I need then all the hours spent in the gym in addition to my road riding and intervals is worth it. There is a reason that Chris Hoy spends as much time as he does in the gym - it works for him.

After a workout with squats, single leg squats or deadlifts you pretty much have to ht the foam roller or you WILL be sore for days.

Hit the foam roller and you'll likely be OK.

Depends on your style of racing. If you are a track sprinter, squats with big weights should be part of your regime, because track sprinting requires an amount of powr that you are never going to develop by just cycling. See here. If you're training for road racing, especially if you're a climber, the regime will be very different.

Armchair science is one thing, real-world is another. There are two "distance" and "RPM" variables here. One for the wheels and one for the cranks. You cannot apply force at the cranks with the distance traveled by the wheels. You must use one of the two:

1. power = (wheel-distance * wheel-thrust) / second
2. power = (crank-circumference * pedal-force) / second

where 1 = 2

You must be a tri-guy who doesn't sprint. Anyone who sprints pulls up on the handlebars to apply more force than available by just standing on the pedal with full bodyweight so it has to be higher than 80 lbs.

Power = ω x Torque

Torque = Power / ω

At 110 RPM and 1500W Torque = 1500 / (2 x π 110/60) = 130 N-m

Assuming you applied constant force and used 175mm cranks that would be the equivalent of approx 75Kg applied at the end of the crank. Since no one actually pedals in cicles the peak load is closer to double or 150Kg (330lbs).

Your calcs were essentially correct but you only pedal with one leg at a time so you should be doubling the 168lbf for the per leg force not halving it.

So how far do the pedals travel? Wait I answered that - 2 m/s.

110 rpm/(60 sec/min) *2*pi*17.25 cm = 2 m/s

So what's the problem?

Yes, one leg at a time, but not only one leg all the time. First double then half. 170 lbf. Final answer.
I was probably mis-remembering 80 kgf.

Not trying to stir the pot but, as has happened in another thread, we still do not know if your answers are simply mathematical calculations and science based or based on real life experience? The op is looking for answers to help his sprint power. As I am a sprinter my answers are based on real world experience not science, in fact I do not use a power meter or heart rate monitor and often leave my computer at home.

As far as I know science operates in the real world. What you really seem to be asking is whether conclusions are based on one single persons observation with questionable or no controls or observations over a large population with at least some effort at control and repeated testing and refining of the results and conclusions. I would have to say the latter.

As to the problem of athlete-based experience, I can think of no better example than Mark Spitz who when asked to describe his stroke gave a long description to the smallest detail of how he moved in the water and generated so much power. The only problem was when he was filmed, his stroke bore no resemblance to what he had described.

Less wrong, but still wrong.

When the left leg is pushing down the left leg is the only one providing power and it provides all the power (any pulling up of the right leg is negligible).

Your calculations assume that the leg is applying a uniform force throughout the pedal stroke which, of course, doesn't happen. The peak force is approx double the average force as shown in the diagram below (from "Force–Velocity Relationship in Cycling Revisited: Benefit of Two-Dimensional Pedal Forces Analysis" S. Dorel et al) for a 1000W sprint:


Note the peak force of 1100N (247lbf). There's a reason top track sprinters (Chris Hoy) have bigger quads than endurance cyclists.

So let's look deeper into this experience. What training modalities have you tried and how did you track performance? Did you consider training with and without weights and did you replace the weight training with something else? If so what? How did you correct for years of experience as you moved from one system to another? How did you measure total training load to determine if the changes in performance were due to the type of training or just changes in training volume? The list goes on and on. We're interested in learning.

I suspect finding out who has the biggest cojones is drifting the thread away from helping the original poster...