Imagine the perfect workout. It would allow you to:
• burn a ton of calories in as little time as possible—think 30 minutes or less
• build muscle for a sculpted physique
• improve your conditioning for short bursts and the long haul
• build bone and keep you safe from fracture and injury
• leave you feeling like an athlete who just competed for a championship
What if you could achieve all this, and when you were done, your body continued with the accelerated calorie burn for as much as a day or two after your workout?
This workout is not a dream. It’s known as high-intensity interval training (HIIT). It is so effective because instead of having you exercise for a long period of time at a steady state (such as jogging), you use intermittent bursts of intense physical effort interspersed with rest, allowing for moments of relief.
There is a catch to HIIT, and this is where some people get lost—HIIT challenges your physical capacities. It’s hard. Some days it may challenge your will to keep going.
But, HIIT is one of those few amazing things in life that gives you back way more than you put into it. Chances are, if you try HIIT, you’ll “love” it for the following reasons:
• Your workout is so short—research shows you can change your body and build strength with workouts ranging from 7 to 30 minutes long.
• Because it’s interval-based and often uses a variety of different lifts, time flies by and it’s less boring and tedious than traditional aerobic training.
• It enhances self worth, physical confidence, and mental toughness, while allowing you to perform feats you never dreamed you could before.
Now that you’re convinced to try HIIT, this article will give you five rules to make it happen with specific workouts depending on your experience level.
#1: Use German Body Comp for Fat Loss.
Who’s It For: Anyone in the general population who wants to lose body fat and have a well-functioning physique. Good for beginners.
Benefits: Fat loss, muscle building, improved metabolism, general conditioning, exercise technique.
German Body Comp (GBC) is a modified form of HIIT that is appropriate for beginning trainees who want to lose fat fast. It allows you to perfect exercise technique and achieve base levels of strength so that you can progress to the more intense protocols listed below.
A typical GBC protocol uses three sets of super set exercises in which you pair an upper and lower body lift. Always focus on movement quality, strictly controlling tempo and using short 30-second rest periods between exercises.
This workout produces a big metabolic disturbance and as much lactic acid buildup as possible. The more lactic acid you produce, the more growth hormone you produce, and with that increase in growth hormone comes greater fat loss.
The quickest way to start this cascade of events is to use multi-joint exercises with short rest intervals.
Sample Protocol:
Day 1 Sets x Reps Tempo Rest
A1: Lying Leg Curl, feet neutral 4 x 8 5-0-1-0 30 sec
A2 Flat Dumbbell (DB) Bench Press 4 x 15 3-0-1-0 30 sec
B1 DB Lunges, Alternating 4 x 12 2-0-1-0 30 sec
B2 Lat Pulldown, Pronated Grip 4 x 15 3-0-1-0 30 sec
C1 DB Romanian Deadlift 4 x 15 3-0-1-0 30 sec
C2 45 degree Trap 3 Raise 4 x 15 2-0-1-1 30 sec
Day 2
A1 DB Squats, Heels Elevated 4 x 15 3-0-1-0 30 sec
A2 Seated Row, Supinated Grip 4 x 15 3-0-1-0 30 sec
B1 45 Degree Back Extension 4 x 15 2-0-2-0 30 sec
B2 Standing DB Shoulder Press 4 x 15 3-0-1-0 30 sec
C1 Leg Press, Medium Stance 4 x 20 2-0-1-0 30 sec
C2 Standing DB Calf Raise 4 x 12 2-0-1-1 30 sec
#2: HIIT With Weights For Fat Loss
Who’s It For: Experienced trainees who want to lose body fat as fast as possible.
Benefits: Fat loss, muscle building, conditioning, and greater insulin sensitivity.
HIIT training with weights takes GBC to the next level, torching a huge volume of calories during and after your workout.
Aside from a better lookin’ body due to more chiseled abs, calves, pecs, and so on, increasing muscle and strength will give you the upper hand against fat loss because they allow you to handle heavier loads with more ease. Plus, being lean and strong is always better than being lean and weak.
A 2012 study by Paoli provides the perfect example of how to use HIIT with weights. Two protocols were tested on trained young men:
1) a Traditional program of 4 sets to failure of 8 exercises with an intensity of 75 percent of the 1RM, or
2) a High-Intensity program of 3 sets per exercise of leg press, chest press, and pull-downs performed using an intensity of 85 percent of the 1RM lifted to failure.
The Traditional program took 62 minutes, and resulted in the following numbers:
• Trainees lifted an average 7835 kg over the course of the workout.
• They experienced an elevation in blood lactate of 5.1 mmol/L post-workout.
• At 22 hours after exercise, they had a 5 percent increase in calorie burn (98 extra calories), from 1901 to 1999 resting energy expenditure/day.
The HIIT program took 32 minutes, and resulted in the following numbers:
• Trainees lifted an average 3872 kg.
• They experienced an elevation in blood lactate of 10.5 mmol/L post-workout.
• At 22 hours after exercise, they had a 24 percent increase in calorie burn (452 extra calories), increasing from an average 1909 to 2362 resting energy expenditure/day.
In half the time, with half the volume, the participants created a profoundly greater metabolic disturbance. Training a program like this a few times a week for a month or two will produce rapid fat loss due to the following three mechanisms:
• The body burned an extra 354 calories during the 24-hour recovery period in its effort to recover from oxygen debt. Anytime you breathe more deeply, your body burns more calories.
During the workout, the limited rest and hard work caused the body’s demand for oxygen to vastly exceed its ability to deliver it to the muscles, producing the huge increase in calorie use.
• Lactate buildup in the HIIT group was double that of the Traditional group. Remember, the intensity at which lactate accumulates is associated with release of GH, the “fat burning hormone.” GH may also improve tissue repair and recovery in the post-workout period.
• The HIIT group also increased their use of fatty acids for fuel to satisfy the high energy cost of the workout. The ability to mobilize and burn fat is vital for keeping you energized while losing fat because it means the body is capable of shifting between fuel sources.
Inability to access fat leads to poor exercise performance and brain “fog” when trying to lose weight.
Sample Protocol:
The protocol used in this study was leg press, chest press, and pull down on machines, 85 percent of maximal load.
The rep scheme was 6 reps, rest 20 seconds, then repped out to failure, rest 20 seconds, and repped out again. Rest for 2:30. Repeat the whole thing for 3 sets for each lift.
Could you substitute free weights (deadlifts and chin-ups for example) for machines and get better results?
Yes, this would be appropriate for savvy trainees. Be sure to sequence exercises so that as you become fatigued, you don’t put yourself at risk of injury due to failing technique.
#3: Use Heavy Circuit Training To Build Strength & Get Shredded
Who’s It For: Athletes and experienced trainees who want to put on muscle and build strength in as little time as possible.
Benefits: Increased muscle mass, fat loss, maximal strength, conditioning.
HIIT isn’t your go-to workout for mass gaining, but it’s perfect for building muscle while losing fat because it triggers hypertrophy and fat burning pathways simultaneously.
For example, a 2011 study from Alcaraz found that an 8-week circuit training program with just enough rest between sets to transition to the next exercise produced greater strength and muscle gains than a traditional program that allowed 3-minutes rest between sets.
In half the training time, the circuit training group lost 1.5 percent body fat and gained 1.6 kg of muscle, whereas the traditional group lost 1 percent body fat and gained 1.2 kg of muscle, making circuit training slightly more effective for transforming body composition.
In addition, the circuit training group increased bench press 1RM by an average of 19.5 kg and the squat 1RM by 44.2 kg. The traditional training group increased bench press 1RM by an average of 17.7 kg, and squat 1RM by 45 kg.
A few things about HIIT make it so beneficial for building muscle:
• You can increase both load and mechanical tension by pairing agonist-antagonist exercises or upper-lower body lifts. This allows for greater activation of growth via genetic pathways and satellite cells, which are key for muscle development.
• It produces significant metabolic stress from the buildup of lactate and hydrogen ions because you allow for little recovery time. The result is the release of growth factors, including cytokines and hormones that correlate with hypertrophy.
Sample Protocol:
The protocol used in the study trained leg curls, bench presses, standing calf raises, lat pulldowns, half squats and preacher curls.
Trainees started with 3 sets of 3 reps per exercise. Sets and reps were increased every 2 weeks so that at the end of the experiment all the subjects were performing 6 sets of 6 reps.
You don’t have to go light with circuit training—this protocol used heavy loads (85 to 93 percent of the 1RM). Do train in an organized fashion by counting tempo and using a clock to keep track of the rest periods.
#4: Do 4-minute Tabata training, a 2-minute maximal sprint, or a 7-minute all-out, bodyweight workout.
Who’s it For? People who have zero time to train but know how to push themselves.
Benefits: Elevate metabolism, boost insulin health, and improve gene signaling.
Scientists have been busy trying to determine the least possible amount of exercise necessary to achieve metabolic and health results. They’re finding that tiny bouts of intense exercise make a big difference for health and well being.
One recent study compared the Wingate protocol (4 to 6 sprints of 30 seconds with 4 minutes rest) with a single, 2-minute maximal sprint. Both improved insulin sensitivity the same amount. The protocols were matched for volume, resulting in the same caloric burn during exercise.
It was what happened in the 24 hours after exercise that was different: The Wingate group had 63 percent higher fat oxidation and the extended sprint group used 38 percent greater fat for fuel in the immediate post-exercise period.
So, even though a Wingate protocol is going to boost metabolism more due to it being more stressful with the repeated sprints, doing a single 2-minute maximal effort workout is worthwhile.
Sample Protocol:
Tabata training, which is a 4-minute set with 20-second maximal effort and 10-second rest can be done with sprints, a sled or other strongman exercise, or body weight exercises.
A maximal effort 7-minute workout that was presented in the ACSM Health and Fitness Journal suggests doing 12 exercises for 30 seconds each, including squats, lunges, jumping jacks, step-ups, and push-ups.
Obviously, you’re not going to see serious strength or muscle gains in just 4 to 7 minutes, but these workouts do have benefits and can “tied you over” if you’re madly busy and can’t do more.
#5: Don’t Train HIIT Everyday: Optimize Recovery!
Who’s it For: CrossFitters and other hardcore trainees who are pushing volume and intensity.
Benefits: Continued adaptations, neuromuscular strength, a responsive central nervous system (CNS).
A 2012 study from Scivak shows why you MUST allow for recovery when training HIIT workouts:
Yes, they produce a huge lactate response for super fat burning, but they also exhaust the CNS and elicit a very high cortisol stress response.
This study tested adrenal hormones in trained college students who did bench press, deadlift, and squat with a pyramid scheme (10 sets starting with 10 reps and decreasing to 1 rep each set). There was no rest between sets and the starting load was 75 percent of the 1RM load, which was decreased if a participant was unable to complete the desired repetitions.
Cortisol was much higher than values reported on all previous research that used the same intensity, primarily because those studies all used rest periods of 1 to 3 minutes.
Cortisol remained elevated for an hour post-workout, but dropped to below baseline the following day. That cortisol was suppressed the day after the workout suggests that the body was still trying to recover from the stress.
Doing this sort of protocol to frequently would cause hormonal imbalances and a catabolic environment would occur.
Optimize Recovery From HIIT:
Depending on your conditioning, goals, and the intensity of your protocol, do HIIT 2 to 3 times a week. Moderate workouts or being active on off-days is recommended.
Also, focus on recovery in the immediate post-workout period. This is prime time for the CNS to recover.
Ideally, you would get post-workout nutrition and recovery therapy after HIIT. Real-world recovery often includes running off to work, picking up the kids, or some other high-stress activity that doesn’t allow your nervous system to recover as easily. Account for this by adjusting training frequency, mind-body strategies, and planning out your nutrition.