If you want to learn endurance training tips that will help you increase endurance to superhuman levels, then you want to read this article series.


There are a variety of little-known, “underground” tactics you can implement to enhance your training effectiveness and efficiency – endurance training strategies that tend to fly under the radar, but can give you lots of bang for your buck if you implement them into your program. These tactics come in handy especially if:

a) time management is important to you;

b) you want to figure out ways to strengthen your cardiovascular, musculoskeletal and nervous system without significant damage to your joints, health, or metabolism.

So let’s jump right in and discover 3 of these little known ways to turn you into an endurance beast. In part 2 and part 3, we will be looking at 9 other ways.

Overspeed Training

Overspeed training is, exactly as it sounds. It is the practice of training your limbs to turnover at a higher speed – a speed over what feels comfortable or natural. Just imagine The Road Runner from the old Looney Tunes cartoons.

Before jumping into the specific techniques of overspeed training, it’s important to understand that by spinning your legs extremely fast on a bicycle, or running at an insanely high turnover, or swimming windmill-style, you’re not necessarily replicating what you plan on doing in a race.

For example, in the case of cycling, research has shown that lower cycling cadences, such as 60rpm, can actually result in significantly better efficiency and economy compared to cadence of 80rpm or 100rpm. And the folks over at SwimSmooth have a fantastic stroke rate chart which shows that many swimmers will actually do just fine with a relatively low stroke count.

But here’s why overspeed training works: it is an effective method to recruit new muscle tissue; specifically by engaging more muscle motor units than if you’d trained at lower speeds. This is called a “neural adaptation,” and you can consider it a form of training for your nervous system. Through overspeed training, not only does your brain literally learn how to fire faster and control your muscles more efficiently at higher speeds, but you also develop more powerful and quick muscle fiber contractions, which comes in handy for hard surges during a race or tough workout.

Contrary to popular belief, you do not need fancy equipment for overspeed training.

While there are certainly devices on the market such as anti-gravity treadmills, which use differential air pressure to reduce your body weight down to as low as 20%, or extremely fast treadmill belts that are combined with a harness which literally hangs you from the ceiling while you’re running, you don’t need these fancy tools. These devices certainly do allow for “extreme” assisted overspeed training in an underweighted or low gravity environment, but you don’t actually need to go out and spend the price of a small automobile on a new treadmill.

Instead, here are some effective overspeed workouts you can easily do with equipment you probably already have, or at least relatively inexpensive training gear.

Downhill overspeed running

Use a dry, non-bumpy grass area that allows you to sprint about 40-50 feet down a slope and then sprint another 40-50 feet once you reached the flat (to allow for the continuation of the overspeed effect without the assistance of gravity). Research indicates a downhill grade of about 5.0% is ideal, but don’t feel like you need to go to the golf course with surveying equipment to find the best slope. Just run down a relatively steep hill that isn’t so steep you fall over on your face. If you really want to get fancy with overspeed running, you can grab a partner (or a pole) and an overspeed bungee for your repeats.

Overspeed cycling efforts

A downhill slope or an indoor trainer works best for these efforts, although you can get them done on the flats in a low gear, such as using your small chainring. After a good warm-up, simply choose the lowest possible resistance that allows you to spin at an extremely fast rate without bouncing in the saddle. Spin at the fastest possible cadence (preferably higher than 120RPM) for a maximum of 30 seconds, and then give yourself full recovery before beginning the next set.

Assisted swimming

For this workout, you need swim stretch cords. I’ve just used a good set of fins to allow me to swim faster, but you’ll get better results with less muscular and cardiovascular fatigue by using stretch cords. With the stretch cords attached to your waist, you simply swim as far away from the wall as possible, then turn and let the cords pull you back at a much faster pace than you’d be able to swim unassisted. If you do this correctly, you’re going to find your stroke turnover rate is incredibly difficult to maintain. You can insert this kind of overspeed training at the beginning or the end of one of your weekly swim sets.

You should know that overspeed running can create significant eccentric muscular damage, caused by your brain attempting to “slow you down” just slightly with each step. The ensuing soreness caused by this protective deceleration can be pretty uncomfortable a day or two after an overspeed workout. To minimize this soreness, introduce overspeed training into your program only after you’ve gotten a solid 6-8 weeks of weight training and plyometric training under your belt. Although swimming and cycling overspeed training doesn’t cause significant muscle tissue damage, your neuromuscular system does need plenty of time to recover and regenerate, so even for these exercise methods, I don’t recommend overspeed sessions more than once per week.

Underspeed Training

Of course, on the complete opposite spectrum of overspeed training is underspeed training. You have a pretty good idea of what underspeed training involves if you’ve ever engaged in a long grinding bike ride up a hill, trekked up a stair mill at a gym, or done a resisted swim training session dragging a parachute behind you or wearing one of those ultra-sexy drag suits.

Compared to overspeed training, underspeed is better suited for building strength and force production capability. Similar to overspeed training, underspeed can also assist in development of efficient movement patterns and muscle fiber recruitment (but without quite as potent a neuromuscular “brain-training” effect as moving your limbs extremely fast). In a podcast interview I did with Ironman triathlon champion Chris McCormack, I was actually surprised to hear about the amount of underspeed “grinding” sessions he actually performs on the bike – sessions which he recommends specifically due to their ability to stave off fatigue late in a long race.

Underspeed training sessions also come in quite handy early in a race season, when strength building and development of proper movement patterns is more crucial than heavy use of intervals and overspeed efforts.

Sample underspeed workouts include:

  • Steep 60-70rpm hill climbs for 5-15 minutes on a bike
  • Running steep hills slowly
  • Climbing a stairmill (with an optional weight vest or set of dumbbells)
  • Performing a series of intervals in the pool, dragging a parachute behind or using a drag suit

Weight training could technically also be considered a form of underspeed training.

Isometrics and Superslow Training

I first discovered a guy named Jay Schroeder in the winter of 2013, when I attended a biohacking conference in which he demonstrated the use of isometric exercise and superslow sets. He uses these techniques with many of the professional athletes he trains, often in combination with electrostimulation.

An isometric exercise, which combines the Greek words “isos” (“equal” or “same”) and “metron” (“distance” or “measure”), involves a muscle contraction without any visible movement in the angle of the joint.  This is in contrast to traditional moving “isotonic” contractions, in which your muscle length and joint angle change throughout the exercise.

If you’ve ever performed a wall squat, in which you sit in an imaginary chair with your back against the wall for as long as you possibly can, then you’re familiar with the teeth-gritting high levels of lactic acid and muscle burn that isometric training can produce. Alternatively, you could simply try this the next time you’re at the gym: lift your normal weight, but take 10 seconds to lift and 10 seconds to lower.

If you really want to take isometrics to the next level, you can use a technique Jay refers to as extreme isometrics, in which you move, but you move very, very slowly. We’re talking 5-10 minutes per repetition. This takes intense focus. Go ahead and just try and do a 10 minute push-up and see what happens to your entire body.

As I mentioned earlier, Jay’s clients also combine heavy weight training or isometric body weight exercises combined with  electrostimulation, and if you happen to own an electrostimulation device, you can recruit even more muscles and enhance the results of your isometric or super slow training.

So how on earth could this type of static or extremely slow movement produce a cardiovascular training response?

The answer is a bit multi-faceted, but comes down to four primary reasons:

Resistance=Endurance Reason #1: Increased Cardiac Output

The cardiovascular response to resistance training is an idea I first encountered when I interviewed the author of the book “Body By Science,” a physician named Doug McGuff, in my podcast episode “Does Weight Training Count As Cardio?”.

As you’ve already learned, your cardiovascular system pumps oxygen and nutrient rich blood to the tissues of your body. The “cardio” part of the word cardiovascular refers to your heart, which is responsible for pumping the blood, and the “vascular” part of the word cardiovascular refers to your blood vessels, which are comprised of an arterial system which transports blood from your heart to your tissues and a venous system which carries blood back from those tissues to your heart. The resistance that your heart has to pump against and the amount of blood your heart can pump out (your cardiac output) is directly influenced by the size of those blood vessels.

To increase your cardiac output, you can

  • increase your heart rate
  • increase your stroke volume (by having more blood or by filling the heart with more blood before each beat)
  • dilate your arteries, which decreases the resistance your heart pumps against (called peripheral vascular resistance)
  • increase the venous return of blood back to your heart

Venous return of blood back to your heart is partially dependent on muscle contractions. In other words, forceful muscle contractions enhance cardiac return.

In addition, a release of chemicals called “catecholamines” occurs as a result of resistance exercise, and these catecholamines stimulate vasodilation in the vessels, which further decreases peripheral resistance and also increases blood flow back to your heart. This decreased peripheral resistance combined with enhanced venous return fills your heart up with more blood and enhances your cardiac output.

An article in the June 1999 issue of the American Journal of Cardiology actually observed this very phenomenon. In the research, a catheter was used to measure pressure changes during a high weight leg press exercise in patients with stable congestive heart failure. The participants experienced significantly increased heart rate and arterial blood pressure, but significantly decreased peripheral vascular resistance and increased cardiac output (that’s just one of many studies that Doug McGuff references in an excellent article he’s written on cardiovascular adaptations to resistance training).

But an increase in cardiac output is just one way that the intense resistance encountered during isometric or superslow training can assist with endurance, because next you get the benefit of the burn itself.

Resistance=Endurance Reason #3: Lactic Acid Clearance

Lactic acid gets a bad rap, but the acidosis or “burn” associated with muscle fatigue has very little to do with the formation of lactic acid.

The development of acidosis during intense exercise has traditionally been explained by the increased production of lactic acid – which causes the release of a hydrogen ion and the formation of an acidic salt called “sodium lactate.” On the basis of this seemingly logical explanation, if the rate of lactate production is high enough, then your body simply can’t buffer those hydrogen ions fast enough, and this event results in a decrease in cellular pH and that dreaded burn.

Exercise scientists call this effect “lactic acidosis,” and it has been a classic explanation of the biochemistry of muscle burn for more than 80 years.

But in fact, there is zero biochemical evidence that increased lactate production causes acidosis and muscle burn or muscle fatigue. As a matter of fact, lactate production can actually decrease acidosis.

So why do muscles burn when you exercise? A more likely mechanism for the drop in pH or increase in acidity during exercise is the breakdown of ATP energy.

It goes like this: water (H2O) is used to break down or “hydrolyze” ATP to make energy, and this results in one acidic H+ ion (from the water) + ADP + P (phosphate) + energy for whatever you need.

As you can see, every time ATP is broken down to ADP and P, an H+ ion (a proton) is released. When the energy and ATP demand of contracting muscles is met by mitochondrial respiration, there is no proton accumulation in the cell. How can this be? Because those same hydrogen ions are used by your mitochondria to recombine ADP and P to regenerate ATP and to maintain what is called the “proton gradient” in the intermembranous space of your muscle cells.

So as long as your mitochondria are efficient at doing this (and that efficiency increases the fitter you get) the longer it takes for that build-up of hydrogen ions to become a burn issue. As soon as your mitochondria fail to supply ATP at the appropriate rate, due to an outmatched number of the necessary transports and enzymes, you get that muscle burn and eventual muscle fatigue.

It is only when the exercise intensity increases beyond steady state exercise that there is a need for greater reliance on ATP regeneration from rapid breakdown of blood, liver and muscle sugar and the creatine phosphate system, which is why high intensity exercise can result in a better ability to generate ATP compared to easy aerobic exercise.

So why is lactic acid associated with muscle burn? Because as you break down sugars more and more at higher intensities, you need more of a molecule called “NAD,” which can actually be supplied by increased lactate production. Thus increased lactate production coincides with acidosis and is a good marker for cell conditions that induce metabolic acidosis. But if your muscles did use sugars and phosphate to generate extra ATP, and did not produce lactate as a byproduct of this use, then acidosis and muscle fatigue would occur more quickly because your mitochondria would get outmatched more quickly, and exercise performance would be severely impaired in the absence of lactic acid production.

While that may be enough to convince you that lactic acid is not the bad guy, just keep reading.

Ultimately, if you train your body at high intensities, you can become very efficient at shuttling lactic acid back up to the liver and converting it into glucose, after which the lactic acid can be “recycled” and used as a concentrated energy source by your muscle (Nelson). This is called the Cori cycle.

So lactic acid can actually be used as a significant fuel source! As you can probably guess, when you include activities that produce high amounts of lactic acid, such as HIIT or with high amounts of resistance or with isometric holds, you can teach your body how to do that more efficiently.

By the way, if you’re using isometrics and experiencing the massive lactic acid build-up that occurs in the local muscle tissue during a set, then you should know about something called “oxaloacetate.”

Most chemical reactions in your body take place in a series of several steps. In chemistry, the rate (or velocity) of a reaction with several steps is often determined by the slowest step, which is known as the rate-limiting step.

A significant rate limiting step of converting lactic acid into glucose is the conversion of the molecule Nicotinamide Adenine Dinucleotide (NAD) into Nicotinamide Adenine Dinucleotide Hydrogenase (NADH). So what does this have to do with oxaloacetate? In studies, acute oxaloacetate exposure enhances resistance to fatigue by increasing NAD to NADH conversion and allowing lactic acid to get recycled and converted to glucose at a much higher rate.

As a matter of fact, along with calorie restriction, enhancing your Cori cycle efficiency is also one of the ways that you can significantly increase the enzyme AMPK, which can upregulate mitochondrial biogenesis and improve both carbohydrate and fuel utilization.

Basically, this means that you can become a complete lactic acid metabolizing endurance beast if you take about 100-200mg of oxaloacetate in supplement form 15-30 minutes prior to a workout that includes high intensity intervals, super slow training, or isometrics.

Resistance=Endurance Reason #3: Better Muscle Utilization

Whether you’re running a marathon, shoveling snow or lifting a piece of furniture, if the wrong muscles are turning on for any given movement, then you have poor technique, you increase your risk of injury, and you produce less-than-ideal force.

But your body can learn how to utilize the correct muscles, and just like any movement, it’s easier to learn how to use the right muscles when you train slow or you hold a position, with an emphasis on maximally activating specific muscle groups. So when you use something like isometrics or superslow training, you simply have less distraction and more time under tension for any particular position you’re trying to learn or perfect. Thus you’re able to sense the proper muscles that you need to activate and better understand how to get there.

Take the lunge, for example. It roughly simulates the single leg “landing” phase of a run. When you’re able to use a superslow or isometric lunge to mentally focus on recruiting the correct musculature for that landing phase, you develop better body awareness (also known as “kinesthesia”) and learn how to properly activate your hamstring during that specific phase of running. In particular, you are learning how to actively pull yourself down instead of simply giving in to gravity and collapsing when your foot strikes the ground.

An added benefit to this improvement in muscle activation is that in addition to learning how to utilize the proper muscles for any given movement, you are also training your joints to move through the full range of motion for that movement. As you move slowly through or deeper into a joint angle, there is a significant amount of stretch placed on the fascia, which is the layer of fibrous connective tissue that surrounds your muscles. As this occurs, you can gain dynamic range-of-motion and flexibility that far exceeds what you might experience from a static stretching protocol such as yoga. For example, by performing 5 minute long deep isometric doorway pushups, I’ve found that my shoulder range-of-motion while swimming has significantly improved.

So how can you utilize isometric or super slow protocols in your endurance training?

a) Include a weekly resistance training session in which you incorporate at least one move or a series of moves performed very slowly. One short but highly effective strength+cardio session that I give many of my athletes once per week can easily be performed using weight machines, body weight, free weights, or a suspension trainer. Simply perform one set of each of the following.

  • Upper body pushing exercise, 5-10 repetitions of 10 seconds up, 10 seconds down (i.e. push-up, machine chest press, etc.)
  • Upper body pulling exercise, 5-10 repetitions of 10 seconds up, 10 seconds down (i.e. pull-up, seated row, etc.)
  • Lower body pushing exercise, 5-10 repetitions of 10 seconds up, 10 seconds down (i.e. leg press, squat, etc.)
  • Lower body pulling exercise, 5-10 repetitions of 10 seconds up, 10 seconds down (i.e. deadlift, leg curl, etc.)

The routine above is similar to what you’ll find in Doug McGuff’s book  and is adapted from his 12 minute routine in the book “Body By Science.“

b) Include an isometrics routine one to four times a month. Simply hold any or all of the following positions for 2-7 minutes, depending on your level of fitness:

c) Include isometric holds as part of your daily habits. For example, twice a week after I finish playing tennis, I slip into the sauna and do a 4-minute lunge hold for each leg, followed by a 4-minute wall squat. Twice a week on the doorway in my office, I do a 5-minute doorway push-up. Later in this chapter, you’ll learn how this fits into the concept of “greasing the groove.”

You can do isometrics as part of your current weight training routine. For example, prior to doing a set of barbell squats, you can perform a 2-5 minute isometric wall squat hold. This can actually have what is called a “potentiating effect.” The exercise scientist Dr. Yuri Verkhoshansky has stated that this potentiation effect can cause an isometric exercise such as a squat hold to increase the force of a similar exercise you do after the hold (such as a barbell or dumbbell squat) by up to twenty percent!

Resistance=Endurance Reason #4: More Motor Unit Recruitment

But muscle is bulky, isn’t it?

You need to understand that there’s a big difference between muscle mass and muscle recruitment. Muscle mass is not necessarily synonymous with strength and power. For example, top Tour de France cyclists appear to have toothpicks for legs compared to powerlifters and bodybuilders, yet they are capable of producing nearly superhuman wattage on a bicycle. Champion swimmer Michael Phelps is one of the most powerful athletes in the sport of swimming, but does not appear to have significant amounts of muscle mass compared to other top male athletes in the sport.

So how is it that a muscle can stay at a manageable, carry-able size for endurance sports, and yet still be capable of producing strength and power?

The answer lies in the relationship between the nerves, the muscle and something called the motor unit. A motor unit is defined as a nerve and all the muscle fibers stimulated by that nerve. Muscle fibers are grouped together as motor units. If the signal from a nerve is too weak to stimulate the motor unit, then none of the muscle fibers in that motor unit will contract. But if signal is strong enough, then all of the muscle fibers in the motor unit will contract.

This is called the “all-or-none” principle.

It doesn’t take much of a signal to recruit slow-twitch, or endurance muscle fibers in a motor unit. It takes a stronger signal to recruit fast-twitch, or explosive muscle fibers. However, the goal of weight training is not to increase the signal to the fibers, but rather to train the body to be able to recruit multiple motor units, whether those motor units are comprised of slow-twitch or fast-twitch muscle fibers. Better athletes have the capability to recruit multiple motor units, which means more fibers are firing, which increases force production.

So, you can have a relatively small number of motor units, but with proper training, can gain the ability to recruit a significant number of those motor units simultaneously. If this is the case, you don’t need much muscle, but just the ability to be able to wholly recruit the muscles that you do have – and heavy resistance training or force production using techniques such as isometrics and super slow sets is how this is achieved.

The four reasons I’ve listed above are not the only benefits of weight training for endurance athletes. Over 20 years of research have successfully demonstrated lower injury rates for the shoulders, knees, hamstrings, low back and ankles in athletes including swimmers, cyclists and runners when weight training was used to strength the soft tissue surrounding and supporting the joints. In some cases, injury prevention is due to correction of a muscular imbalance through the use of targeted weight training, and in other cases, injury prevention is due to the increased ability of a joint to absorb impact.

Need even more proof that you can become a better endurance athlete by using resistance training?

Check out this abstract from the paper “Resistance Training to Momentary Muscular Failure Improves Cardiovascular Fitness in Humans: A Review of Acute Physiological Responses and Chronic Physiological Adaptations.”

Research demonstrates resistance training produces significant improvement in cardiovascular fitness (VO2 max, economy of movement). To date no review article has considered the underlying physiological mechanisms that might support such improvements. This article is a comprehensive, systematic narrative review of the literature surrounding the area of resistance training, cardiovascular fitness and the acute responses and chronic adaptations it produces. The primary concern with existing research is the lack of clarity and inappropriate quantification of resistance training intensity. Thus, an important consideration of this review is the effect of intensity. The acute metabolic and molecular responses to resistance training to momentary muscular failure do not differ from that of traditional endurance training. Myocardial function appears to be maintained, perhaps enhanced, in acute response to high intensity resistance training, and contraction intensity appears to mediate the acute vascular response to resistance training. The results of chronic physiological adaptations demonstrate that resistance training to momentary muscular failure produces a number of physiological adaptations, which may facilitate the observed improvements in cardiovascular fitness. The adaptations may include an increase in mitochondrial enzymes, mitochondrial proliferation, phenotypic conversion from type IIx towards type IIa muscle fibers, and vascular remodeling (including capillarization). Resistance training to momentary muscular failure causes sufficient acute stimuli to produce chronic physiological adaptations that enhance cardiovascular fitness. This review appears to be the first to present this conclusion and, therefore, it may help stimulate a changing paradigm addressing the misnomer of ‘cardiovascular’ exercise as being determined by modality.


What did you think of these endurance training tips? Have any that you’d like to share? Let me know in the comments below!

Ready for part 2 of this article series?