Are you wondering how much resistance a functional trainer can provide? Or you’re looking for a trainer that can really give you a hard training that grows your muscles and strength? Here’s what you need to know about the weight stacks of functional trainers and the effective resistance.
Most functional trainers come with dual 150 or 160 lbs. weight stacks that can be upgraded to 200 or 210 lbs. However, most cable gyms use a 2:1 ratio which means the effective resistance at the handles is only half of the selected weight. This is done to improve range of motion and smoothness.
Why and how do manufacturers use a leverage ratio for functional trainers and what are the models with the highest effective resistance? Keep reading to find out.
Functional trainer cable gym weight stacks
Below you can see a chart of the most popular functional trainers and how much their weight stacks weigh. You can also see if it’s a single or double stack.
|Brand||Model||# Weight Stacks||Weight stack weight/side (lbs.)||Ratio|
|Life Fitness||G7 Home Gym||2||160/210|
|Life Fitness||Signature Dual Pulley||2||390||1:4|
|Reeplex||Commercial Dual Arm||2||200|
|Pivot Fitness||Functional Trainer HM3360||2||160||1:1/1:2|
|Pivot Fitness||Cable Smith Machine FSR400||2||160|
You can see that most functional trainers have a 150 lbs. or 160 lbs. weight stack. Many manufacturers have an option to upgrade the weight stack with 50 lbs. to 200 or 210 lbs. One thing to look out for is if a machine has one or two stacks. The majority has two separate stacks. If a functional trainer has two stacks, it means that both cables are attached to a different stack. A few machines have just a single stack. In that case both cables are attached to the same stack.
There are a few machines with heavier stacks but more on that below. The absolute weight of the weight stack is not very useful if you don’t know about the lever ratio the trainer uses.
Functional trainer lever ratio
The raw weight of the stack doesn’t tell the whole story. It’s actually quite misleading how many manufacturers market these machines.
Many functional trainers have a pulley system that divides or multiplies the weight at the handles by a certain ratio. A 1:2 ratio is the most common. That means that selecting 150 lbs. on the weight stack only results in 75 lbs. of resistance at the other end of the cable. A 1:1 ratio is actually quite rare as well as some others like; 2:1 and 1:4.
Most functional trainers have a pulley ratio of 1:2. This means that lifting a 150 lbs. weight stack only produces 75 lbs. of resistance at the handles. This is done to increase the range of motion of the machine and increase the smoothness of the movement.
Now your next question will probably be: why? It certainly was my first reaction. There are two big reasons why they do this;
- Range of motion
Let’s take a look at those two reasons in detail.
Range of motion
A big reason is the distance the cable can be pulled out. On a good machine this is about 80”. That means if you have a handle attached to the cable, you can pull it 80” away from the pulley. The average functional trainer is about 85” tall. That’s the total height though. The top of the weight stack is already at +-30” height at rest. That means there is not enough height to lift the stack 80”.
That’s where the ratio comes in. The effect of the 1:2 ratio is that for every 2” you move the handles, the stack only moves up 1”. That means 80” of handle travel is 40” of stack travel. And when the stack only has to move up 40”, suddenly you have enough space.
With a 1:1 ratio, you’d have to limit the range of motion to about 40” which just isn’t enough for many exercises.
While the range of motion is the most important reason, smoothness is another big one. The 1:2 ratio means the movement you feel in your hands when pulling/pushing the cable is much smoother.
Most of that hast to do with the speed of the weight stack. If you lift a weight at a certain speed, that weight wants to keep going in the same direction. The faster the weight moves, the longer/further it wants to keep going.
The weight stack in a functional trainer is no different than any other weight. In a cable gym machine, the weigh stack is connected to a cable which is connected to the handles you hold. So if the weight keeps moving while you stopped the movement, the cable will go slack for a moment and then you suddenly get a jolt because the weight stack is coming back down and is at a certain speed already. This gives a very jerky feeling especially on faster repetitions.
The ratio halves the speed at which the weight stack moves. That means the weight stack is much less likely to keep moving up further after you stop the movement. Since kinetic energy is quadratic, halving the speed reduces the jerkiness by much more than half.
A smoother moving machine is more predictable, easier on the joints, provides more consistent resistance and reduces wear on the machine. There are quite a few benefits.
Manufacturers don’t do this to ask you for more money. There are good reasons as you can see above. If it was possible to get the same results with a 1:1 or even 2:1 ratio, it would have been done a long time ago since this would be a lot cheaper to manufacturer. I do think that most manufacturers should be clearer about this though.
Ok, so there are some good reasons for using a ratio but how does it work?
The cable runs through a pulley system which halves (in case of a 1:2 ratio) the resistance but also halves the movement. I’m not going to be able to explain this correctly so check out the video below for an in depth explanation if you’re interested.
When you’re lifting weights, you’re not simply lifting a certain amount of weight. You’re moving an amount of weight through space which means a certain amount of work is done. If you lift the same amount of weight but only half a repetition only half the amount of work is done. In this case your arms still go through the full range of motion but you’re only lifting the weight stack half the distance. This translate in a halving of the resistance at your hands.
How much resistance is enough?
How much resistance do you actually need in a functional trainer? If you’re used to lifting with barbells and dumbbells you might be afraid that 150 lbs. just isn’t enough.
How much resistance is enough is a similar question to; how long is a piece of string. There are so many variables that it’s impossible to answer in one paragraph. How much resistance you need completely depends on how strong you are now, how strong you want to become, what your training goals are.
And then there are other factors like age, gender, training experience, training style, other available equipment. So you can understand this question has a different answer for everyone.
Resistance isn’t the only deciding factor. Size is another important part. Click here to find out how big functional trainers are and how much floor space you need to use one.
The best way to figure it out is to go to a gym that has one of these machines. Most good gyms will have one or more. When you’ve found one, just try out how much weight you can properly use.
Now if you’re completely new to working out, your strength will increase very quickly in the first few months but progress after that will be much smaller. But if you’re already working out now, progress will be slower.
Some tips to figure out how much resistance you need;
- Try it out on a similar machine
- Check www.strengthlevel.com to see what other people are using
- If you’ve got a barbell setup for heavier lifts and are using the functional trainer for accessory exercises, 150/160 lbs. stacks are likely enough.
- People who want to become really strong and muscular, 200/210 lbs. is a good upgrade.
- Doing a similar exercise on a cable machine vs. dumbbells/barbells, you’ll use a little less actual weight.
- If the resistance is not enough, you can change variables like amount of repetitions and rest period to make the workout more challenging.
3 Highest effective resistance functional trainers
You want a functional trainer that can challenge you and provide a good training impulse to grow your muscle and strength. Which functional trainers have the highest effective resistance after taking the leverage ratio into account?
#1 Pivot Fitness HM3360
If you’re looking for the maximum effective resistance, here’s your best option. The weight stacks only weigh 160 lbs. which isn’t anything special. However, the cool trick this functional trainer has that is pretty unique;
You can choose to use either a 1:1 or 1:2 ratio. There are two cable ends in the pulley. One cable end will have a 1:1 ratio while the other has a 1:2 ratio. So you can choose the ratio by attaching your handles to the other cable. So one cable end has 160 lbs. of resistance while the other has 80 lbs. This means you can choose between a higher resistance or a bigger range of motion. Choose whatever fits the specific exercise you want to do.
Since there are two stacks, that means a combined maximum effective resistance of 320 lbs. That should be plenty for most people.
It’s also pretty cheap. Not the best looking and highest quality out there but even then it provides good value for money.
There’s one problem though; There is no distributor for this brand in North America. If you’re in Europe or Asia, this is a great option. Otherwise, you’re out of luck. Sure you could import it but these things are big and heavy. The shipping fees and import taxes would likely mean it’s not worth the effort.
You’re going to be better off with one of the next two machines.
#2 Body-Solid S2FT
The king of high resistance functional trainers. While the base model only has a 160 lbs. weight stack with a 2:1 ratio, the weight stack can be upgraded to a whopping 310 lbs. This means you can get up to 155 lbs. of resistance per side.
Not as good as the number 1 on this list but it does so in a better way. It’s only 5 lbs. off anyways. That’s not a big deal. The Body-Solid is better because it provides almost the same resistance as the Pivot but with the benefits of the 1:2 ratio (smoothness and range of motion). That makes this a much nicer machine to actually use. Well worth the 5 lbs. loss of resistance in my opinion.
However, the 310 lbs. stack version can be a bit difficult to find and is not cheap. Worth it? Up to you but the next option has some really cool features and can be hand for only slightly more money.
#3 BodyCraft XFT
For most exercises the BodyCraft XFT doesn’t have a very high effective resistance just the standard 150 or 200 lbs. And it doesn’t even have dual stacks but a single stack. So what is it doing here? Well, it has some really cool features that make this machine worth a long look.
I’m not going to pretend how the pulley system in this functional trainer works exactly but here’s what it does;
- When using one pulley, the ratio is 1:2. That means the maximum resistance is 75/100 lbs.
- When using both pulleys at the same time, the ratio of the total is 1:1. So per side the resistance is still 75/100 lbs. but combined it’s 150 lbs.
Now we get to the really cool part: The built in barbell system. If you’re familiar with a smith machine, this will look familiar but this is better. A smith machine only allows the barbell up and down. This machine allows the barbell also move freely horizontally so it can move freely in two planes. There is no side to side movement like there would be on a completely free barbell.
As standard this barbell has a 1:1 ratio so the maximum resistance is 150 or 200 lbs. However, there is a double up function. You basically attach the cables of the functional trainer part to the barbell and now you’ve got a 2:1 ratio. This means the maximum resistance on the barbell is 300 or 400 lbs.!
The good thing about this, is that on most exercises, you don’t actually need the high resistance. But with a barbell, you can move much more weight. Most barbell exercises are compound movements which means they move multiple joints at the same time. This results in more muscles being used at the same time which means you can move more weight but these movements are also more tiring.
All in all, this machine doesn’t have the highest single pulley resistance out there but it does have a ton of resistance where it really counts. It adds a whole new set of exercise options compared to a normal functional trainer as well. Downsides? It’s expensive but you get a lot for the money.