Last year I published my most popular post to date: Is Exercise a Stress Reliever or a Stress Amplifier? It explained that while we often think of exercise as stress reliever, it can often have the opposite effect.

That’s right. Instead of helping your overall health, your mode or intensity of exercise could be contributing to why you’re constantly getting hurt, sick, or unable to sleep.

If that's how you feel, you may want to do some long slow cardio..

While this may seem obvious to you, realizing this fact put me light years ahead of where I was as a coach. Everything started to click. I realized why certain people with frequent back pain, or who were always sick, didn't necessarily feel better after their workout. And sometimes they even felt worse.

So the inevitable question is: how do you know where on the stress spectrum you fall, and that you're not sabotaging yourself with your mode of exercise?

Below are my three favorite tools to help regulate your training sessions. I highly suggest incorporating one of them into your next session as it offers objective insight into how you're recovering. It'll also ensure that you're not adding to your stress level...by thinking your exercise routine is adding to your stress level.

1. Heart Rate Variability

I’m far from an early adopter. I didn’t have a smartphone until 2013 and I didn’t have an Uber account until two weeks ago. Some of my workout shirts date back to 2003, and I refuse to trash the sneakers I’ve worn almost every day since 2011.

I know, I’m very exciting.

So while Heart Rate Variability (HRV) is not a new technology, you can understand why I only started using it 2 months ago.

But the results have been enlightening. It’s quickly become my go-to training tool and it’s taken my own training to a higher level. Here’s why.

I guess you could say I have peaks and valleys.

Most people think our heart is beating like a metronome – a steady beat that rarely alters. But if we’re healthy, our heart beat is the opposite with a large variability in between beats. It’s this time between beats that illustrates the alternating pieces of our autonomic nervous system – sympathetic and parasympathetic. As a refresher:

Sympathetic – Fight or flight, turns on when we inhale
Parasympathetic – Rest and digest, turns on when we exhale

If we continually alternate between the two, it illustrates a healthy balance within our body and we have a large variability between beats. And when our nervous system is in good balance, we’re going to be well rested and ready to train hard.

But if we’re stressed, our parasympathetic system gets the boot. Our sympathetic system runs the show and we end up with an elevated resting heart rate and we become a metronome - with a lower variability in between heart beats. It's normal to be sympathetic in the short term (i.e. during a training session), but an inability to stop being "fight or flight" means our body is constantly fighting mental or physical stress. This screws with our recovery and gives us more aches and pains.

If you're stuck in the "fight or flight" mode, high intensity exercise is only going to make things worse. Since you're already stressed, adding more stress in the form of exercise is going to make you frustrated or worse. You'd benefit much more from long slow cardio, a good night of sleep, and making sure you're eating healthy meals. The gainz can wait for another day.

If you're still not convinced, here's a great link to more information on heart rate variability. It explains how HRV was a better indicator of overtraining for runners than resting heart rate, and how it was also highly correlated with the performance of Olympic weightlifters.

2. Grip Strength

This is hardly the first time I’ve beat the grip strength drum. Besides from announcing your presence with authority, having a strong handshake is strongly linked with overall health. But for training purposes, it's also closely linked with your nervous system.

The more well rested you are, the stronger your grip strength will be. If you've been sleeping poorly and had a few too many cold ones over the weekend, your grip won't be the same. As with HRV, grip strength gives an objective measure to determine the appropriate intensity for training. If you have a weaker grip, it's probably best to save those heavy singles or that physically demanding 5x5 plan for another day.

In order to use grip strength as a barometer for readiness, you can use whatever you have available. I like using bottoms up kettlebell work - carries or presses, specifically - in the beginning of someone's session to determine their readiness. Sometimes I'll even add in some of this work if I can't get a good read on someone's stress levels. I'm sneaky like that.

Another option would be to use the Captains of Crush grip trainers. A favorite of mine, these industrial strength grip trainers routinely leave me humbled. Like bottoms up kettlebell work, you can use these at the beginning of your session to see where you stand.

3. Psychomotor Vigilance Tests

If you're picking up what I'm putting down, you realize that we're not just training the body. We're training the brain.

And if we're training the brain, we need to make sure we're well rested and recovered before we can go hard in our workouts. So what better way to view our readiness than by using a test that focuses on our reaction and attention?

There isn't a ton of research illustrating this connection with exercise, but I've noticed it firsthand and it's not new to other physical preparation coaches. For example, before I started using HRV I had been using Lumosity - not as a tool to increase my memory or thinking skills, but as a tool for my heavy lifts. On days I did very well, I did very well at the gym. When I scored poorly, I didn't have my best day of lifting. Even better, I can now correlate it with HRV as I'll do them both the same day. Further anecdotal evidence came from the morning of the Tactical Strength Challenge, as I ended up hitting three personal records and ranking in the top 10 percent of the world.

If you're interested, there are plenty of other apps and tests available through a quick Google search. But if it's good enough for NASA, it's good enough for me.