With busy schedules, hectic work and social lives, and (for most of us) the innate fear of long, drawn out workouts, one of the biggest barriers to hitting your body composition goals is time. This is where high-density training (HDT) comes in — a combination of both cardio and strength training perfectly packaged into one short workout. Not only can they be performed in the gym, but they’re also as versatile as you are imaginative.

These training methods are not only high in volume and quick to perform, but they’re also great for fat loss and conditioning. And best of all, they'll let you hit the gym like a ninja — no one will have even noticed how quickly you were in and out.

RELATED: Avoid These Group Programming Mistakes

Read on to find out not only what high-density training is and how you’ll benefit from it, but a breakdown of the best protocols out there, too.

What is training density?

A good place to start here is to define exactly what density means. In physics, of course, density refers to unit volume. It's sort of a similar meaning in the gym, too. In the context of resistance training, density refers to exercise where there is a high work to rest ratio, and the total volume of reps is elevated for a given time frame.

How is training density measured?

You'll often see training density measured as reps multiplied by load. Sometimes it's then additionally multiplied by the total number of sets per exercise to get "total tonnage."

For example, if you perform five sets of 10 back squats in 10 minutes, your training density for that particular movement in a 10-minute session would be 50 reps. If the load you lifted was 100 kilograms, your total tonnage for that session would be 5,000 kilograms.

And whilst it’s easy to come off subject in a discussion of the pros and cons of measuring density, one thing is clear: high training density basically means doing more in less time.

How can you increase training density?

Essentially anything that increases the work you perform in a given time period will increase session density. This could include:

  • More reps and sets
  • Higher load
  • Reduced rest periods
  • Shortened session duration

These are the hallmarks of a good high-density training (HDT) program.

42327116 - muscular couple doing jumping squats on a wooden box

What are the benefits of high-density workouts?

The best high-density methods combine elements of cardio and strength training. Throw in some high work to rest ratios and you’ve got a pretty unique recipe for fat loss and conditioning.

HDT is a simple but effective way of losing fat, building unbreakable conditioning, and even packing on muscle.

The fast-paced nature of high-density circuits will ramp up your autonomic functions in a similar way to traditional high-intensity cardio. That means that your heart and breathing rate will soar, your stroke volume and tidal volume will elevate, and your core body temperature will go through the roof.

How does that benefit you?

Well, the effect of high-density training on your metabolism means you’ll burn lots of calories during your workout, and potentially continue to expend energy for hours after your workout. This will help you reduce your body fat, but at the same time maintain or even build muscle mass due to the local adaptations from resistance training.

Add all of these factors together and it’s a sure-fire way of achieving better body recomposition.

Train harder but smarter.

When you’re working out at a high intensity, you don’t need to train as long to create an overload effect. This makes HDT a very time-efficient method of exercise.

HDT workouts are tough. Throw in the fact that, due to the sheer intensity, your oxygen uptake is rapidly increased, and you’ll improve conditioning, too. This means that your heart will become stronger, and other metabolic markers of health such as insulin sensitivity can improve, too.

And not all of the benefits are physiological either. Hard workouts like HDT teach resilience and determination. They forge a strong character and a never-give-up attitude. All of these are important not just in the gym but also in other areas of your life.

In a nutshell, the benefits include:

  • Optimizing body composition
  • Improving aerobic and anaerobic performance
  • Increasing time efficiency

Which high-density training approaches are best? 

There’s no one-size-fits-all approach to HDT. And whilst there are sometimes only subtle (almost pedantic) differences between some of the protocols, they are all worth trying. You might prefer one to another, or even find that you benefit physically from a particular workout and not a different one.

There are lots of different ways that you can incorporate HDT into your program. And that’s really the beauty of it. HDT is as versatile as your imagination. You can do it in the gym, outdoors, or even in your back yard if you have to. All you need are some simple protocols to follow.

These are the holy grails of body composition training. Here are the best ones to get you started.

1. Escalating Density Training (EDT)

It’s hard to talk about density training without giving homage to EDT. Why? Because this system kicked off a bit of a training revolution for me. It was the first method I came across that used this sort of approach to training, and I’ve loved it ever since. If you want to burn fat and improve leanness then this is where it’s at.

The first thing you do with an EDT workout is plan an overall time frame. This could be 10 minutes or 30 minutes; it’s up to you. Traditionally, though, you’d be looking at 15 to 20 minutes to maintain workout productivity.

Then you plan your content. The usual approach is to pick two non-competing exercises such as a lower body exercise (A) and an upper body exercise (B). They can be body weight, free weight, or fixed resistance — whatever your training goal, preference, and physical condition allow. Once you’ve done this, make sure you choose a weight that’ll allow around eight to 15 reps to fatigue.

Start with A and complete as many reps of it as you can (or want to). Once you’ve done this, move onto B and do the same. You’ll shift between the two exercises continuously, auto-regulating your rest times and reps as you see fit. The end goal is to complete as many total reps as you can in the timeframe that you chose.

You’ll record the total reps as a PR and aim to beat it by next session. And once you’ve beaten it by 20% or more, you can increase the weights to continue the overload process.

42327141 - back view of a muscular couple throwing ball in the air

2. High-Intensity Resistance Training (HIRT)

High-intensity work is guaranteed to get your heart racing, improve your metabolism, and ramp up your athleticism. Throw in resistance training and you can add muscle conditioning to that list too. This session works well for those who want the benefits of interval training but don’t like cardio-based training.

HIRT uses similar principles to its sister program, high-intensity interval training (HIIT), in that it is a protocol based on work to rest ratios. You’ll complete a number of strength exercises back to back with minimal rest. There’s no real hard and fast rule regarding the total number of exercises, but traditionally you’ll choose between four and six. Too many and the circuits become overly long and complicated.

The key here is to maintain a high heart rate, blood flow, and work output, so making sure you don’t have two exercises in a row that work the same muscles is a key consideration.

Once you’ve done this, you need to hammer away at each exercise for a period of 10 minutes (or more if you want). You’ll flow through your circuit taking rest periods only when you need to. The aim is to hit as much volume as you can.

Portable equipment works well here so you can set up a contained circuit that saves you rushing around the whole gym in an attempt to keep your heart rate elevated. It also reduces the chance of any gym-goer's worst fear: someone taking your machine half way through a circuit.

Once you’ve completed your 10 minutes you can set up another circuit and go again.

3. Peripheral Heart Action Training (PHA)

PHA also harnesses the key impact factors of a good conditioning program: strength training, a circuit-based approach, and lots of hard work. It is designed to improve muscle conditioning, maximal oxygen uptake, and autonomic efficiency.

This system was built on traditional circuit training principles. And similar to HIRT training, it involves organizing a small number of exercises into a logical, non-competing order so as to limit localized lactate accumulation. The aim is to keep blood flowing around the body, hence the term peripheral heart action.

This workout can be short and sharp or it can be longer and more grueling. Aim for five to six exercises and complete 12 to 15 reps for each one. The load you choose should be challenging, but it’s important that you don’t go too heavy, as you’ll just beat up your central nervous system before you get the chance to hike up your heart rate.

Choose a pre-determined rest time between exercises. 30 seconds or so works well, as it’s just long enough to reduce latent fatigue but not long enough to fully recover. Once you’ve completed the circuit you can rest one to two minutes and then go again. Repeat until you either run out of time or you’ve hit your maximum productivity.

Images courtesy of Wavebreak Media Ltd © 123RF.com

Lee is an MSc-qualified consultant lecturer, speaker, and content writer. He is a published academic and professional writer and has delivered talks at a number of conferences including the COPA Growth medical conference in London. He is also involved in primary sport science research with other sport scientists across a number of institutions. Check out his website at The Muscle Mechanic.