Is High Intensity Always Best? Heart Rate Variability & Readiness Training
I have to admit something out loud....
In order to effectively explain my programming and thoughts to clients, I draw comparisons and use metaphors. Storytelling and imagery really helps a person who may be an expert, not in the field of fitness, to grasp and understand my coaching concepts and where I plan to lead them. But there is one example I’ve used in the past, and commonly hear others use that just doesn’t cut the cake (maybe I shouldn’t use that one either…).
“Your body is like a car”
Your body is really a sophisticated cluster of synapses, neurotransmitters, mechanoreceptors, hormones, auto regulatory systems, living tissue (organ/bone/joint/muscle) that reacts to every sensory stimulus it receives. If it rains, a car just lets the water fall on it and lets it run off; eventually the sun and heat will dry it. Nothing will change inside the car to adapt to the bad weather, it just sits there. If a tire blows, then you just simply replace the tire and the new tire will perform just like the old one and so will the other three. The gas tank is always the same size and although gas prices may change, nothing will change about the quantity of fuel it will need to run normally. Our human bodies perform nothing like this.
We need to adapt to life changes, training demands, weight fluctuations and the toll of emotional roller coasters. The types and quantities of foods you need to eat depends on your metabolic health and how often or intense you exercise. The latter also depends on the former.
Training and Adaption
Training is a stressor intentionally imposed on the body. That is all – no more, no less. My job as a coach is to determine what type of stress, where and the appropriate dosage to place on each individual. By nature, training is catabolic and directly breaks down muscle, bone and ligament tissue so it can later grow stronger to meet the stressful demands of training. It also challenges the sympathetic and parasympathetic nervous systems. Your sympathetic nervous system (fight or flight) is what raises heart rate, blood sugar, adrenaline and cortisol. Those are all valuable attributes of strength, power and athleticism and important parts of a solid training program.
This sounds all hunky dory until you realize there’s another piece to this puzzle. The fact is, we are not dealing with cars, we are dealing with humans. People possess the unique capacity to emotionally stress ourselves into the dirt and knowingly swallow toxins. If promised a dri-fit shirt and a metal thingy, we may even sprint for a few hours on two hurt knees. We are very unique animals. A person is only capable of handling so much stress on a given day and if they are chronically stressed, can stay in somewhat of a catabolic state due to the compounding stress of daily life on top of training. Essentially weightlifting, high intensity training and endurance training could be someone’s best friend or a sword in the gut.
How someone responds to training will ultimately boil down to their capacity to handle stress. This will depend on numerous factors that is difficult for a coach to assess. However, you do have a tool that could help you dose the right intensities for your clients on an individualized basis - Heart rate variability (for more info, read my ebook on HRV).
Heart Rate Variability (HRV)
Someone’s stress levels will always be revealed in their:
- Resting Heart Rate
- Heart rhythm
Chronic stress affects everyone differently and greatly affects someones ability to recover from stress. Ironically, while many coaches and athletes are focused on the integrity of their training regimen, the adaption to training happens in the hours away from the gym recovering. Too much chronic stress prevents recovery, growth and maximum adaption.
HRV is a fantastic tool to assess your athlete’s, client’s or your own readiness. Since we are not dealing with machines who predictably function regardless of the circumstances, a coach’s experience and intuition can only predict the outcome of a training protocol with partial accuracy.
How to use HRV effectively
One important thing you need to know is that HRV, or any tech for that matter, is not a training program. It gives you information about your training program. Sound strength and conditioning micro and mesocycles can still be planned out to great detail. However, the individual insight this analytic provides, gives the coach or athlete a chance to adapt and modify the training program before symptoms of over training begin. Although there are plenty of great apps out there like Bioforce HRV (the one I use), you must be able to interpret the information in order to make the right choices.
With HRV, higher scores are generally a sign of readiness. When I say readiness I’m referring to the individual’s capability of incurring more stress and recovering from it. If an athlete or clients HRV score is particularly low that day, that’s a sign that the nervous system is losing responsiveness. It’s up to you, the coach to determine why. Training should be fatiguing so one low score doesn’t mean you need to take any action just yet, but if it does slide for a second or 3rd consecutive day you should pull back roughly 20-30% of the training load or volume for that training session.
Reasons HRV scores may be low:
- Lack of sleep
- Too low calorie diet
- Poor hydration
- Too much training
Things you can modify in a training program to respond to declining scores:
- Volume of training- sets/reps/duration
- Load or intensity
- Number of total training days
- Type of training- mobility, high intensity, aerobic, hypertrophy, water sport (swimming/paddleboarding)
TIP: Should you need a lower intensity day than originally planned, you may perform the same training plan at sub 75% HR. Cortisol (major stress hormone) production begins at 75% HR and excessive levels would be counterproductive. Movement however, is very helpful in reducing inflammation in the joints and increasing blood flow. By incorporating low intensity mobility or movement training into a program at the right times, you will be able to bolster the recovery process without putting more unnecessary stress on yourself or athlete.
With all of the factors that can affect someone’s response to stress, it’s incredibly important that coaches are at least able to assess it and be responsive. After all, the goal of training is to adapt and grow stronger, leaner and more athletic; not to just repetitively exercise.