It’s generally correct that there are limitations to relying upon a cardiovascular movement to build large muscles. But if your objective is to use cardio to provide a supplementary workload to select muscle groups for the purpose of further engaging them above and beyond what occurs during targeted weight-training sessions, there are options that will help with that.
What kind of options? I’m glad you asked…
For the Chest
Among the best chest-endurance movements you can do, even if it’s decidedly unconventional and likely to elicit stares, is the bear crawl. The best way to replicate this in an at-home machine would probably be to get down on all fours on a treadmill. Since that’s not very fun, the Jacob’s Ladder machine is going to be your ideal (and very expensive) purchase for building chest endurance at home.
For a cardio machine that can help you get some pectoral activation while you remain upright, the driving motion of the SkiErg will have you doing just enough work that you won’t need to feel like too much of a slacker if you skip a few evening’s worth of push-ups.
For the Shoulders
It’s difficult to expect cardio machines to train the shoulders because shoulders are very difficult to efficiently train in the first place. This is because they’re ball-in-socket joints that swivel, so any form of unidirectional training is going to be insufficient to train an entire shoulder.
The key here is finding an exercise that works the shoulders in multiple directions against some form of legitimate resistance. And as much as SkiErg fans (and I’m one of them) would love to claim that it provides adequate shoulder resistance during the upward lift of the handles, the handles pretty much lift themselves upwards and drag your hands along for the ride.
All of which makes this category one of the rare cases where an elliptical machine — with the requirement that you work against the handles to push them forward and pull them backwards — is arguably the most effective builder of shoulder muscles amongst home cardio machines. Admittedly, though, I’m far from enthusiastic about this endorsement.
For the Back
Now we’re talking. Because there are real-world means of travel that rely heavily on your back muscles to provide the bulk of the locomotive force that drives the movement, it should come as no surprise that efforts to replicate those movements in at-home cardio machines would result in products that heavily target them. Obviously, the first thing that comes to mind is a rowing machine like the Concept2.
However, there are other machines worth considering, like the SkiErg, which works the lats by approximating a near straight-arm pulldown motion with every stroke, along with the mountain-climber machine, which engages the lats to whatever extent you decide. Not to be outdone, on its most demanding resistance settings, the elliptical can provide you with a demanding back workout when you alternate lat engagement by pulling straight back against the handles.
For the Abs
Chiseled, prominent abdominals are so frequently prized that fitness advertising often jumps through literal hoops to claim their products efficiently train them. It’s true that any movement that necessitates the clenching and contracting of the midsection can technically claim to train the abs, but there’s a huge difference between featuring the abs in primary and secondary capacities during your training, and very few cardio devices set them along a path to full contraction.
That said, many people don’t need to isolate their abdominals at all in order to generate amazing six-packs. Some of that may be owed to favorable genetics, but most of it is the result of engaging in resistance exercises that necessitate core engagement even when the abdominals aren’t the primary focus.
With this in mind, Jacob’s Ladder and most climbing machines mandate major core engagement for stabilizing purposes. Meanwhile, rowing machines often conclude their stroke at an angle that causes a serious abdominal contraction, and the drive of the SkiErg delivers a significant contraction to the abdominals. And so, regular use of these two machines will probably eliminate the need for targeted abdominal training.
For the Arms
Your arms are essentially the conduit through which most of the muscles of the upper body are trained. You can’t perform the bench press or do any push-ups without heavily loading up your triceps, and you can’t perform any type of rowing, pull-up or pull-down movements without taxing your biceps. On top of that, it’s practically impossible to physically manipulate any heavy weight without working your forearms to some degree.
Thus, whether or not a cardio device isolates the arms is usually the furthest thing from a person’s mind when they’re deciding which machine to take home. However, anything that works the arm along its hinge joint at the elbow, either through a pushing or pulling motion, is requiring some sort of contribution from either the biceps or triceps. Therefore, it should come as no surprise that the rowing machine, SkiErg, mountain climber and elliptical will all receive mentions in this category.
For the Legs
Duh! The simplest of the bunch, as the overwhelming majority of cardio machines are very leg-heavy in their focus. My personal recipe for respectably skipping leg day at the gym — which will still require you to exert a considerable amount of effort — is to pair the stepmill with the rowing machine. Doing so will punish your legs in brutal fashion, while engaging them in a manner that’s extremely close to how they’re recruited for work in real-world settings.
While rowing in the weight room is rightly considered to be a back-focused training activity, the bulk of the muscle activity on a cardio rower is conducted through the hard-driving extension of the legs. The stepmill will keep the muscles of your legs engaged in a muscle-strengthening manner for hours-on-end if you desire, and the direction and elevation of your stride can easily be varied to target different portions of your leg muscles in distinct ways. Similar benefits are available through Jacob’s Ladder, and the basic movement of the mountain climber drives the leg through the ideal range of motion for targeting the quads and glutes.