The Numbers You Need to Know to Exercise Efficiently

by | Updated: December 4th, 2016 | Read time: 7 minutes

Athletes know their stats. It’s one of those funny quirks you probably have. Even the most creative, numbers-averse athletes have a random knack for mentally calculating pace per mile, 75% of max heart rate and the conversion of kilometers to yards. Though impressive as all that on-the-spot brain work is, the numbers you need to increase efficiency and improve overall performance are not so easily computed.

Your fancy Garmin watch spits back lotts o’ fancy stats, and it’s all great information to look at, analyze and be aware of. But if you’re really looking for performance improvement, there are a few numbers you need to hone in on: max heart rate, lactate threshold, VO2 max and your bioenergetic power score (BEPS).

These Numbers Help You Achieve Energy Efficiency in Training
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Your max heart rate

This is the easiest of them all. Anyone undergoing a long-distance training plan (i.e. a marathon) or who is familiar with high-intensity interval training like Orangetheory Fitness, understands heart rate training, which is based on your age-predicted max heart rate (APMHR). Knowing this number allows you to train in various heart rate zones, which is important for a number of reasons:

  • Customization – Heart rate zones are personalized based on your age with some consideration of gender and fitness level.
  • Aerobic efficiency – With some consistent training in higher heart rate zones, your body will adapt and become more aerobically efficient. This means harder intensity exercise will start to feel easier than they once were and your body will be able to maintain a higher heart rate for longer periods of time.
  • Cardiovascular health – Working within a mix of anaerobic and aerobic zones can help support a healthy heart overall. Some people have seen an improvement in their heart rate recovery rate (aka how quickly your heart rate comes down after a workout).
  • Caloric burn / EPOC – It’s no surprise that higher heart rate zones burn more total calories. However, lower heart rate zones have an equally important effect, as well. Lower zones help your body burn fat and help your muscles recover. That being said, alternating between high and low heart rates (interval training) during a single workout can offer the most caloric deficit. Interval training creates what’s known as excess post-oxygen consumption, or EPOC. Maybe you’ve heard of the “after-burn effect.” That’s EPOC.


To calculate your max heart rate, most personal trainers or fitness programs will use the above mentioned APMHR. The formula is simple: 220 minus your age. It’s the quickest and easiest number to calculate, though there may be a few other factors that play into heart rate zone training, such as lactate threshold…

Your lactate threshold

Lactate threshold is the level of exercise intensity where your blood concentration of lactate increases exponentially. This is typically due to a decrease in oxygen intake, decrease in your body’s ability to flush out lactate, increased use of fast-twitch muscle fibers and/or an imbalance between glycolysis and mitochondrial respiration (ATP production). When your body is producing more lactate than it can remove, you will quickly feel fatigued and nauseous. (Sidebar: lactate is actually not the reason your muscles feel sore days after a tough workout; inflammation is the culprit.)

Lactate is not all that bad, though. According to a University of New Mexico article, lactate in the liver acts as a building block for glucose production, which other parts of your body use as fuel. But when you’re working out at high intensities, the body produces so much it can’t keep up. The more you push that lactate threshold up, the better your body will be able to perform at higher intensities for longer periods of time. In other words, it will take longer for you to feel queasy even when working your hardest.


The only accurate way to assess your lactate threshold is through a series of blood tests, taken during a timed workout. Some coaches will match this threshold to a specific heart rate or heart rate range in order to develop a more effective training program. This has been debated among scientists and physiologists. However, it helps athletes to have a heart rate connected to lactate threshold, so you can easily monitor your exercise efforts at any given point.

Your VO2 max

VO2 max is your maximal oxygen uptake during the highest intensity exercise you can manage. According to sports medicine expert, Elizabeth Quinn, VO2 max is “generally considered the best indicator of an athlete’s cardiovascular fitness and aerobic endurance” (Quinn). The theory is that the more oxygen you’re able to use during high-intensity exercise, the more energy your body can produce. Obviously, the more energy you can produce, the longer you can exercise. This is especially important to long-distance runners or triathletes.

Though the end result is similar (you can go harder for longer), there is a difference between lactate threshold and VO2 max. Lactate threshold is calculating blood lactate levels, so the fatigue you feel is from lactate not flushing out of your blood fast enough. Exhaustion at VO2 max is a result of you breathing as hard as you can possibly breathe. Both lactate threshold and VO2 max are beneficial indicators of maximum effort, so you’ll have a leg up if you know these numbers.


To determine VO2 max, a runner would hop on a treadmill and breathe into a tube that collects and measures exhaled gases while speed and incline gradually increase until you’ve reached exhaustion. The maximum recorded rate of oxygen consumption is considered your VO2 max. It sounds simple, and it is. However, it does require special equipment and professional monitoring just like your lactate threshold and bioenergetics power score. Speaking of which…

Your bioenergetics power score (BEPS)

Bioenergetics is a field of biochemistry that dives deeper into the energy flow through living organisms. Everything your body does requires energy, so where does that energy come from? Coffee, maybe. But chemically speaking, energy comes from ATP, or adenosine triphosphate. Bioenergetics includes ATP production, ATP usage and the relationship between energy systems. This includes the exchange of energy and amount of energy available to function or perform the activities you love (swim-bike-run, perhaps?).

According to Go! Athletics founder and exercise physiologist, Shannon Grady, “the human bioenergetics power output is a closed system with a distinctive set of variables that can be measured and measured quite precisely by combining physiological, biochemical and movement data.” All activities and human functions can be “defined along the human bioenergetic power continuum” (Grady). For instance, running a marathon requires less bioenergetic power compared to what’s needed to run your fastest 5K. Knowing your bioenergetic power score (BEPS) at various points can reveal any physiological dysfunction and whether your training plan is providing the right stimulus to engage or improve your physiological power. BEPS is a more accurate and personalized report of what’s going on inside – much more specific than what VO2 max and lactate threshold can provide.


You’ll need to undergo Physiological Profile Testing (PPT), which is a controlled test utilizing metrics of speed, power, heart rate and blood lactate. To be more specific, PPT involves running 800-meter repeats and getting your finger pricked after each interval (to test blood lactate). You’ll run until you can’t run any faster, recording your heart rate along the way, as well. The actual calculations are done by the experts of Go! Athletics. They are looking at eight different markers, or systems, along the bioenergetics power continuum. After testing, you’ll get a BEPS for each of these eight systems. Here’s the breakdown of each system and its function:

Aerobic Foundation (AF) – The goal of AF is to develop the aerobic system to its fullest, which includes increasing fat metabolism, increasing the number of aerobic enzymes, increasing the size and number of mitochondria, increasing capillarization (the more capillaries you have, the faster oxygen and nutrients can get to your muscles) and increasing the rate at which your body clears lactate. This system sets you up for optimally improving all other systems.

Prolonged Aerobic Capacity (PAC) – In this system, you’re working on developing maximum speed that you can maintain for 60 minutes or longer.

Lactate Tolerance, Clearing & Capacity (LTCC) – This system is solely focused on clearing lactate, increasing lactate tolerance and increasing sub-maximal aerobic capacity.

Aerobic Rate Capacity-1, -2 & -3 (ARC) – There are three progressive systems within this one. However, each one serves to improve fundamental training adaptations, including stroke volume (the amount of blood pumped from a ventricle of the heart in one beat), maximal rate of oxygen consumption, lactate tolerance and lactate clearing. Again, these are progressive, meaning ARC-1 is a little more aerobic-based than ARC-2; and ARC-2 is a little more aerobic-based than ARC-3.

Anaerobic Rate Capacity-1 & -2 (ANRC) – These two progressive systems are the start of a predominately anaerobic state, meaning you’re taking in less oxygen now. The six systems before ANRC were all mostly aerobic, though many are a combination of aerobic and anaerobic. The purpose of ANRC is to, quite obviously, increase your maximum anaerobic capacity. Subsequently, you should notice an increase in max lactate buffering.