These days it seems that everyone is looking to get as strong and jacked as possible. They implement the best training programs, eat all the best foods, and take the right supplements in order to maximize their strength gains. Although there is constant debate over which training style is best for optimizing strength, it seems that most will agree cardio has no place in strength sports. After all, marathon runners are small and weak compared to the elite powerlifters of the world. Why would you spend your time performing an activity that seems to have an effect opposite of those gained from strength training? Upon first inspection, this logic seems to hold weight. However, a deeper look at the physiology surrounding both training modalities exposes some unexpected truths. While it may be true that individuals who train primarily for endurance are not as strong as pure powerlifters, it doesn’t necessarily mean that cardio has no benefit for those who train for strength. In fact, it’s possible that you are missing out on serious gains if you choose to neglect your conditioning altogether.
The Skinny on Cardio
For years, lifters have pointed to an apparent interference effect between strength training and endurance training. Each training style elicits a specific cascade of physiologic effects within the body which are aimed at improving your ability to perform within that domain. Specifically, it has been shown that endurance exercise seems to activate mechanisms in the body which inhibit muscle protein synthesis. MPS is thought to be one of the major players when it comes to strength adaptations. So obviously, this presents bad news for those looking to maximize their strength. However, much like everything that happens in the human body, we can’t just look at one piece of the puzzle to draw conclusions.
Early studies that looked at concurrent training (simultaneous endurance and strength training) seemed to find that endurance training did seem to have a negative effect on strength. Those who strength trained alone saw greater adaptations compared to those who trained concurrently. While this seems to give further evidence to stay clear of cardio, we need to look a bit deeper. The methods and criteria for these early studies were simple and perhaps did not represent the community of heavy lifters or the type of cardio in which they would partake. In fact, most studies that have investigated concurrent training lack a bit of carryover to the real world for one reason or another.
This isn’t the fault of the researchers but is instead a product of scientific research itself. It is difficult to study highly specific subsets of the population and even more difficult to implement training programs that are tailored to each person. This does not invalidate the results that were obtained from these studies either. We can absolutely conclude that traditional, long duration endurance training and moderate intensity resistance training seem to counteract each other in healthy, physically active adults. But the characteristics I just described don’t necessarily represent people who train for muscle and strength. What about people like you who resistance train with high intensity? What happens when you sprinkle in some cardio into an otherwise strength specific training program? In the grand scheme of things, cardio might not be a bad thing after all.
Benefits of Cardio for Strength Training
Now that we’ve explored ways that cardio could negate strength gains, let’s discuss the ways that cardio could actually enhance your strength. One of the main adaptations to cardio is the improvement of cardiovascular fitness (hence the name). This term encompasses many aspects of the body including the capillarization of tissue, gas exchange in the cells, and blood flow throughout the body. Simply put, when we engage in some sort of conditioning work regularly, our body responds by increasing capillary density in muscles being used and upregulating key mechanisms that lead to more efficient gas exchange and oxygen utilization. Our muscles are then able to receive more oxygen-carrying blood, and extract and use more of that oxygen for energy production.
But how do these adaptations apply to strength sports which rely primarily on anaerobic (without oxygen) energy pathways? Well, it’s not always about directly serving the energy pathway in terms of seeing improvements. One thing we know for sure is that muscle temperature is important for optimal function. The increase in blood flow to the muscle that we get from conditioning work will allow our muscles to reach proper temperature more quickly as well as retain heat for longer periods of time. Think of the time you might spend resting between sets or perhaps between attempts at a meet. Being able to keep your muscle temperature at an adequate level for longer could make a big difference in being ready for another heavy set or recruiting enough force for a 1RM attempt. It could also help prevent injury from attempting to lift a weight that is heavier than your tissue is ready to bear.
Similarly, an improved aerobic base will help to reduce the amount of rest that is needed between sets. The act of squatting a heavy barbell may be primarily an anaerobic event, but recovery from that event is mostly aerobic. The faster you’re able to replenish your ATP-Pc system after a set (through utilization of oxygen for ATP production), the more consistent you can be with your performance on the following set. This again touches on your ability to recover between attempts at a meet.
Additionally, the increased blood flow through the muscles allows for faster removal of waste products. These waste products can change the environment of the muscle tissue, making it less efficient and weaker. So not only are you recovering faster between sets, you’re also able to establish a more optimal environment within the muscle for maximal force production.
Perhaps the most important adaptation that we would get from adding in some conditioning is recovery between sessions. The increase in blood flow in the region of the body that has undergone some serious lifting is huge in facilitating recovery. This is accomplished, in part, by the delivery of nutrients to the damaged muscles as well as the shuttling away of any waste products that could be damaging the muscle further.
Enhanced recovery means less soreness as well as a quicker return to full strength in the muscles that were used. This means we are able to train more frequently and more effectively which, over time, leads to greater strength gains. This is especially true during the lead up to a competition when frequency and intensity are generally more pronounced. Being able to squeeze out a few more sets with heavier weight could mean the difference in a podium finish when all is said and done.
It is difficult to ignore all the potential benefits one could receive from adding a bit of cardiovascular conditioning into his or her program. The increased recovery during and between lifting sessions will undoubtedly lead to better results when it comes to adding strength. However, these benefits have long been masked by the negative cloud that surrounds cardio in the minds of serious lifters.
The fact of the matter is that smart application of cardiovascular conditioning in your program will enhance your results, not negate them. However, the type, duration, and mode of conditioning matters when it comes to how it will affect your strength. Furthermore, each person is unique and requires an individualized program in order to meet his or her fitness needs. So it is best to treat your conditioning programming with the same care that you would your strength training. Once you do get the right combination of cardio and lifting in your program, you’ll be sure to reap the rewards of improved fitness and strength!
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