Nowadays, more and more people love cardio workout exercises at home. The reasons are varied:
– lack of time
– stress relief
– immersion in nature
– dislike of weight training.
In this second article (here the link to the previous one), we will analyze cardio scientifically and learn how to apply it correctly to the second method presented in this series: Power Aerobic Cardio.
Workout Parameter
As mentioned earlier with Aerobic Cardiofitness, the key parameter for structuring our cardio workout exercises at home is heart rate.
In this specific workout type, heart rate is no longer fixed but fluctuates. The range will always be between 65% and 85% of your maximum heart rate.
Below 65% of maximum heart rate, the workout is not considered effective for training purposes, so this threshold should never be crossed. The workout will be divided into steps, each focusing on achieving the target heart rate set for that phase.
Let’s look at a practical example to clarify.
PAC: HOW TO
Suppose we want apply the PAC method at our cardio workout exercises at home, and we want to run outdoors.
The intensity, as noted, is not constant. For this, we need to calculate heart rate levels corresponding to 65%, 70%, 75%, 80%, and 85% of maximum heart rate.
The idea is to divide the workout into five steps. Here’s how the session could look: after a 5–10 minute warm-up, you could start running for 12 minutes at 65% maximum heart rate.
Since 65% is a moderate to low intensity, in the second step, you should run at 80% maximum heart rate, and since this is a high intensity, maintain it for 4 minutes.
In the third step, decrease the intensity and, for example, lower it to 75%, maintaining it for 12 minutes, and so on until the workout is complete.
In this way, a PAC (Power Aerobic Cardio) workout lasting 44 minutes is structured.
There are no strict rules for organizing heart rate levels. For example, you could start your workout at 70%, then move to 85% in the second step, drop to 65% in the third, and so on. The key to this workout is that after a high-intensity slot, a lower-intensity slot must follow, then increase intensity again in the next slot, and so on until the circuit is complete.
Other than that, you can arrange the sequence of heart rates as you like.
Between one step and another of this workout, stopping is not allowed, so the work must be continuous.
Once the circuit is complete, add a 5–10 minute cool-down with stretching.
What’s behind
The alternating intervals, or slots, are intentional.
Lower-intensity slots are intended as active recovery (indicated with R in table), while higher-intensity slots are the working phases (indicated with W in table).
A graph of this workout would show that during the session, a significant amount of time is spent “resting,” as the active recovery slots outnumber the working slots.
The blue line representing the workout average sits close to 70% of the workout.
What does this mean? It means that by adjusting the duration of these slots, you can set the overall intensity of the workout, shifting the average line higher and making the workout more intense and effective.
If we look closely, there is an exact work-to-recovery ratio of 1:3 between the duration of active rest and work.
This observation allows us to understand that a fundamental parameter of this workout is precisely the W/R ratio.
By adjusting this ratio, the overall workout intensity can be set.
Progression
Starting from these basic notions, how can we create progression with this method?
First, you could create a routine with less active recovery time and more work time, perhaps by having three work slots and only two recovery slots.
You could also modify the work-to-recovery ratio, as mentioned earlier. If you want to maintain the workout but make it more challenging, you could change from a 1:3 ratio to a 1:2 ratio. For example, maintain a work time of 4 minutes but recover actively for 8 minutes instead of 12, resulting in a more intense workout of 32 minutes total.
Alternatively, you could design an even more demanding workout with a 1:1 ratio, such as 4 minutes of work followed by 4 minutes of recovery, for a total of 20 minutes.
Additionally, in the example, we set a work time of 4 minutes, but nothing prevents us from setting it to 3, 5, or 6 minutes and calculating the active recovery time as a multiple of this value. The only rule in this protocol is not to drop below 3 minutes in the work slot.
With these simple observations, you can already create numerous training progressions without changing the base exercise,
which in this case is running. The third and final parameter you could change to create progression is calculating the working heart rate using the Karvonen method instead of the Cooper method.
Conclusion
As you’ve seen, there’s no need for fancy equipment or complex routines to create an effective training progression.
Just apply pure science to your workouts.
An important consideration: some of you may want to train in the gym and apply this protocol to the cardio machines in the gym.
Instead of running, you could use a treadmill, bike, or elliptical and apply the exact protocol.
However, this could become monotonous over time, so a further step could be switching equipment for each slot. For example, you could use a bike for the 4-minute work slots and then move to an elliptical for the 12-minute recovery slots.
This is entirely doable, but the equipment must be close by and immediately available since this workout does not allow breaks.
Finally, let’s conclude with the most crucial consideration: what effect does this work protocol have on EPOC? The Excess Post-Exercise Oxygen Consumption induced by PAC is significantly greater than that produced by Aerobic Cardiofitness.
It is a highly effective intermediate protocol for those looking to lose weight and have been training for some time.