Coaches/athletes often design/perform workouts with the goal of training the cardiac (heart) muscle. As with any muscle that we train, we are looking for physiologic adaptations like power, endurance, etc. Cardiac muscle should be trained not only to assure its healthy state but to reach physiologic adaptations that will collaborate in our overall performance during racing as well as daily activities like using stairs.
Understanding basic heart physiology like heart rate, cardiac output and peripheral resistance is important because they are some of the variables or goals that we look to improve.
Heart rate is the number of contractions of the heart in one minute.
Cardiac output is the volume of blood that is ejected from the heart also in one minute.
Peripheral resistance is the resistance of the blood vessels against the flow of blood coming from heart. These vessels are located in our skin, muscles and organs, and the greater the resistance is, the greater the work the heart must do to eject blood. This resistance is increased temporally by stress, smoking, fat burners and excessive consumption of coffee. It’s also increased by wearing tight/compressive clothing. Peripheral resistance is also increased by atherosclerosis, secondary to high fat intake, and some diseases of fat metabolism.
Imagine that we have to move across 20 yards of sand, carrying ten boxes, with each box weighing 20 pounds, in a time limit of one minute (200 pounds per minute). If we only are capable of lifting 20 pounds, we have to make 10 fast trips in order to move all the boxes on time, and we will finish completely tired and with a high risk of injuries. But if we train our lifting muscles and move on a paved surface, we could smoothly lift 40 pounds and make only 5 trips, and finish in better shape and with a lower risk of injuries.
This is the same for the heart. A healthy, strong heart ejects the same amount of blood as an unfit heart but with less frequency. And if we help it by providing a smooth conduction system (low resistance vessels) by avoiding stress, tobacco, atherosclerosis, and other factors, then it will be easier to the heart to perform its duties.
The heart training is also progressive.
Stage 1. The initial basic plan to train our heart (similar to the low to medium volume and low weight of the gym) is controlling heart rate and peripheral vascular resistance. For 6-8 weeks the workouts are 60-90 minute bouts of heart rate Zone 2 and occasionally Zone 3, while eliminating factors that could increase the resistance of the blood vessels (e.g. tobacco, high intake of fats, excess coffee, etc.). It is important to avoid long aerobic workouts in this stage because of the cumulative stress to the body. Stress control is imperative, and can be managed with stress control therapy and yoga. At the end of this stage we could see that we can run or cycle a little faster but with the same heart rate.
Stage 2. During the second stage of 4-6 weeks, longer progressive aerobic intervals (Zone 3 with active rest on Zone 2) workouts are used. The cumulative stress of the long aerobic runs or rides will challenge our heart, temporarily increasing the resistance of the vessels (the medium to high volume and medium weight of the gym). At this stage, we must still focus on stress control and avoid medium volume high rate-anaerobic workouts.
Stage 3. At the third stage (2-4 weeks) we can use short (no more than 20-25 minutes) anaerobic interval workouts in Zone 4 with active rest on Zone 2-3 and occasionally short bouts of Zone 5 or very short bouts of Zone 6 all with active rest on Zone 1 or 2. These workouts will challenge the heart´s capacity to eject blood efficiently at a higher rate, and must represent only 20-25% of the total weekly volume. The remaining volume is a mix of long aerobic workouts in Zone 2-3 and intervals in Zone 3 focused on muscle endurance.
At the end of this training plan focused on heart health, you should be able to perform faster rides and runs with a lower heart rate. This training program fits well on off-season, so these coming months would be ideal to try it.