21-Day Bootcamp Fitness Challenge: Total Body Revamp

As a former British Royal Marine Commando, I’ve attended numerous bootcamps over the years. Granted, these were not fitness bootcamps, but the basic intention was the same: total immersion for rapid results.

Nowadays, as a veteran personal trainer, I use bootcamps to help my clients achieve their health, fitness, and body composition goals in double-quick time. Bootcamps throw you in at the deep end, forcing you to adapt and overcome obstacles and plateaus.

And while bootcamps are meant to be tough, if you stay on course, you’ll come out the other side in better shape than when you started. They break you down, so you come back better and more capable than before.

In this article, I share a tried and tested 21-day bootcamp-style fitness challenge that mixes high-intensity interval training (HIIT), strength exercises, and core workouts to revamp your body in just three weeks.

Related: Special Forces Training: How To Be Fit For Anything

Bootcamp Basics

Every bootcamp has rules, and this one is no different. Keep the following in mind as you power through the next three weeks of workouts:

Consistency is King

Make sure your schedule is clear so you can commit 100% to this bootcamp. You’ll need about an hour a day for three weeks straight, so don’t start unless you know you can be consistent. Missing workouts will undermine your results and reduce the benefits of the program.

Prioritize Recovery

21 days of back-to-back workouts will push you to the brink of overtraining, but that’s kinda the point. It’s only by exploring your limits that you discover what you are truly capable of. That said, you must pay attention to recovery, so you don’t fall over the edge and quit the program before the end.

Related: 8 Ways to Speed Up Recovery After Training

So, make sure you get a solid 7-9 hours of sleep per night, keep a lid on your stress levels, and avoid doing too much additional physical activity. And definitely don’t do any extra workouts!

Eat for Success

As every soldier knows, food and water are critical for the success of any mission. It’s often said that an army marches on its stomach, and complex supply chains ensure that troops never run out of grub.

Or that’s the plan, anyway…

While you won’t be behind enemy lines, you still need to pay close attention to what you eat and drink to ensure your body has all the fuel it needs for energy, recovery, and growth.

Plan your meals for the next three weeks so you know what you are going to eat and when. Build your diet around complex carbohydrates, i.e., whole grains, vegetables, lean protein, and healthy fats.

Not sure where to start? Check out this guide to simple healthy eating.

You can also allow yourself a single cheat meal per week. However, avoid going overboard as doing so could interfere with weight loss and fat burning.

Related: 7 Ways to Stop Cheat Meals Ruining Your Diet

Listen to Your Body

While this 21-day bootcamp is meant to be challenging, it should not be so hard that it leaves you injured or feeling unwell. On military bootcamps, there are instructors who remove candidates if they are at risk of getting hurt.

You’ll have to act as your own instructor by listening to your body and leaving the bootcamp if you feel you’ve had all you can take. A few minor aches and pains are to be expected, and you’ll probably feel tired, too.

However, if you are in pain or feel unwell, the smart thing to do is stop and try again when you feel more prepared.

You should also modify the workouts if any of them are beyond your current abilities. It’s almost always better to lower the intensity slightly so you can complete all the workouts than have to quit because you tried to do something that you weren’t ready for.

Warm-Ups are Compulsory

Start each workout with an appropriate warm-up. Warming up reduces your risk of injury while enhancing exercise performance. Make sure you spend ten minutes or so preparing your body and mind for what you are about to do.

Start with 5-10 minutes of easy cardio followed by dynamic mobility and flexibility exercises for your main joints. Spend extra time on any muscles or joints that still feel tight.

Related: How to Warm Up for Strength Training

21-Day Bootcamp Fitness Challenge

This bootcamp is designed to develop all-around fitness and strength while burning fat and improving your mental toughness. To do this, you’ll be doing several different styles of training in rotation:

1. Strength Training
2. High-Intensity Interval Training (HIIT) and Core Exercises
3. Low-Intensity Steady State (LISS) Cardio

There are no rest days in this 21-day bootcamp, but some workouts are easier than others, which should provide enough active recovery for you to complete the entire program without needing a break.

The workouts are also progressive, i.e., they get more challenging as the days pass. This will ensure your fitness levels continue to increase.

This is your schedule for the next three weeks:

	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
Week 1	Strength Training	HIIT & Core	LISS	Strength Training	HIIT & Core	Strength Training	LISS
Week 2	Strength Training	HIIT & Core	LISS	Strength Training	HIIT & Core	Strength Training	LISS
Week 3	Strength Training	HIIT & Core	LISS	Strength Training	HIIT & Core	Strength Training	LISS

Week 1

Use this week to get used to the workouts and training seven days in a row. On an intensity scale of 1-10, this week should mostly hit 7s and 8s.

Workout 1: Strength Training – Upper Body

	Exercise	Sets	Reps	Recovery
1	Bench press	2-3	10-12	60 seconds
2	Seated row	2-3	10-12	60 seconds
3	Dumbbell shoulder press	2-3	10-12	60 seconds
4	Lat pulldown	2-3	10-12	60 seconds
5	Triceps pushdown	2-3	10-12	60 seconds
6	EZ bar biceps curl	2-3	10-12	60 seconds

Workout 2: HIIT & Core   

Perform three laps of the following sequence of conditioning and core exercises, doing as many good-quality reps as you can in the time allowed. Rest two minutes between laps.

	Exercise	Time	Rest
1	Air squats	30 seconds	30 seconds
2	Push-up	30 seconds	30 seconds
3	Reverse crunch	30 seconds	30 seconds
4	Jump jack	30 seconds	30 seconds
5	Bench dip	30 seconds	30 seconds
6	Russian twist	30 seconds	30 seconds

Workout 3: LISS   

Do 30-40 minutes of easy to moderate intensity cardio, keeping your heart rate between 60-70% of your age-adjusted maximum.

Options include:

• Jogging/running
• Swimming
• Cycling
• Rowing
• Elliptical

Workout 4: Strength Training – Lower Body

	Exercise	Sets	Reps	Recovery
1	Goblet squat	2-3	10-12	60 seconds
2	Seated leg curl	2-3	10-12	60 seconds
3	Lunge	2-3	10-12	60 seconds
4	Romanian deadlift	2-3	10-12	60 seconds
5	Standing calf raise	2-3	10-12	60 seconds

Workout 5: HIIT & Core

Using the cardio machine of your choice, do the following HIIT program followed by the specified core strength exercises. 

Work	Rest	Repeat
60 seconds	120 seconds	X 6

---

	Exercise	Sets	Reps	Recovery
1	Plank	3-4	45 seconds	60 seconds
2	Side plank	3-4	45 seconds	60 seconds
3	Skydiver	3-4	45 seconds	60 seconds

Workout 6: Strength Training – Full Body Circuit  

Perform the following exercises as a non-stop circuit. Rest no more than 10-15 seconds between exercises and 1-2 minutes between laps. Maintain a brisk pace throughout to challenge your muscles and cardiovascular system.

	Exercise	Laps	Reps
1	Leg press	2-3	12-20
2	Chest press machine	2-3	12-20
3	Seated row	2-3	12-20
4	Step-up	2-3	12-20
5	Shoulder press machine	2-3	12-20
6	Lat pulldown	2-3	12-20
7	Triceps cable kickback	2-3	12-20
8	Biceps cable curl	2-3	12-20

Workout 7: LISS

Take your workout outside and go rucking (hike with a loaded backpack or weighted vest) for 60 minutes. Take breaks as required and remember to stay hydrated. Aim to carry 10-15% of your body weight for resistance. 

Week 2

Your second week builds on what you did in the first. However, the training volume is a little higher, and the exercises are slightly more demanding.

Workout 1: Strength Training – Upper Body

	Exercise	Sets	Reps	Recovery
1	Incline dumbbell bench press	3-4	8-10	90 seconds
2	Inverted row	3-4	8-10	90 seconds
3	Barbell shoulder press	3-4	8-10	90 seconds
4	Close grip lat pulldown	3-4	8-10	90 seconds
5	EZ bar skull crusher	3-4	8-10	90 seconds
6	Seated dumbbell curl	3-4	8-10	90 seconds

Workout 2: HIIT & Core   

Perform four laps of the following sequence of conditioning and core exercises, doing as many good-quality reps as you can in the time allowed. Rest 90 seconds between laps.

	Exercise	Time	Rest
1	Squat jump	40 seconds	20 seconds
2	Push-up	40 seconds	20 seconds
3	Hanging knee raise	40 seconds	20 seconds
4	Jump rope	40 seconds	20 seconds
5	Diamond push-up	40 seconds	20 seconds
6	Saxon side bend	40 seconds	20 seconds

Workout 3: LISS   

Do 40-50 minutes of easy to moderate intensity cardio, keeping your heart rate between 60-70% of your age-adjusted maximum.

Options include:

• Jogging/running
• Swimming
• Cycling
• Rowing
• Elliptical

Workout 4: Strength Training – Lower Body

	Exercise	Sets	Reps	Recovery
1	Back squat	3-4	8-10	90 seconds
2	Lying leg curl	3-4	8-10	90 seconds
3	Reverse deficit lunge	3-4	8-10	90 seconds
4	Single-leg Romanian deadlift	3-4	8-10	90 seconds
5	Donkey calf raise	3-4	8-10	90 seconds

Workout 5: HIIT & Core

Using the cardio machine of your choice, do the following HIIT program followed by the specified core strength exercises.

Work	Rest	Repeat
75 seconds	105 seconds	X 7

 

	Exercise	Sets	Reps	Recovery
1	Kneeling cable crunch	3-4	15-20	60 seconds
2	Cable woodchop	3-4	15-20	60 seconds
3	Cable Romanian deadlift	3-4	15-20	60 seconds

Workout 6: Strength Training – Full Body Circuit

Perform the following exercises as a non-stop circuit. Rest no more than 10-15 seconds between exercises and 1-2 minutes between laps. Maintain a brisk pace throughout to challenge your muscles and cardiovascular system.

	Exercise	Laps	Reps
1	Hack squat machine	3-4	12-20
2	Dumbbell bench press	3-4	12-20
3	Single-arm dumbbell row	3-4	12-20
4	Cable pull through	3-4	12-20
5	Smith machine shoulder press	3-4	12-20
6	Wide grip lat pulldown	3-4	12-20
7	Overhead triceps extension	3-4	12-20
8	Incline dumbbell curl	3-4	12-20

Workout 7: LISS

Take your workout outside and go rucking (hike with a loaded backpack or weighted vest) for 90 minutes. Take breaks as required and remember to stay hydrated. Aim to carry 10-15% of your body weight for resistance. 

Week 3

The last week of this 21-day bootcamp will push you to your limits. But, stay strong, and hang on until the end. After all, as the saying goes, what doesn’t kill you makes you stronger!

Workout 1: Strength Training – Upper Body

	Exercise	Sets	Reps	Recovery
1	Paused bench press	4-5	6-8	2 minutes
2	Pull-up/chin-up	4-5	6-8	2 minutes
3	Alternating dumbbell press	4-5	6-8	2 minutes
4	Pendlay row	4-5	6-8	2 minutes
5	Dumbbell French press	4-5	6-8	2 minutes
6	Zottman curl	4-5	6-8	2 minutes

Workout 2: HIIT & Core

Perform five laps of the following sequence of conditioning and core exercises, doing as many good-quality reps as you can in the time allowed. Rest 60 seconds between laps.

	Exercise	Time	Rest
1	Split squat jump	50 seconds	10 seconds
2	Push-up	50 seconds	10 seconds
3	Flutter kicks	50 seconds	10 seconds
4	Lateral hurdle hops	50 seconds	10 seconds
5	Dive bomber push-up	50 seconds	10 seconds
6	Plank	50 seconds	10 seconds

Workout 3: LISS   

Do 50-60 minutes of easy to moderate intensity cardio, keeping your heart rate between 60-70% of your age-adjusted maximum.

Options include:

• Jogging/running
• Swimming
• Cycling
• Rowing
• Elliptical

Workout 4: Strength Training – Lower Body

	Exercise	Sets	Reps	Recovery
1	Zercher squat	4-5	6-8	2 minutes
2	Good morning	4-5	6-8	2 minutes
3	Leg press	4-5	6-8	2 minutes
4	Kettlebell swing	4-5	6-8	2 minutes
5	Single-leg standing calf raise	4-5	6-8	2 minutes

Workout 5: HIIT & Core

Using the cardio machine of your choice, do the following HIIT program followed by the specified core strength exercises.

Work	Rest	Repeat
90 seconds	90 seconds	X 8

---

	Exercise	Sets	Reps	Recovery
1	Bicycle crunch	3-4	3-4	15-20
2	Oblique cable crunch	3-4	3-4	15-20
3	45-degree back extension	3-4	3-4	15-20

Workout 6: Strength Training – Full Body Circuit

Perform the following exercises as a non-stop circuit. Rest no more than 10-15 seconds between exercises and 1-2 minutes between laps. Maintain a brisk pace throughout to challenge your muscles and cardiovascular system.

	Exercise	Laps	Reps
1	Dumbbell sissy squat	4-5	12-20
2	Close grip dumbbell press	4-5	12-20
3	T-bar row	4-5	12-20
4	Zercher good morning	4-5	12-20
5	Javelin press	4-5	12-20
6	Underhand grip lat pulldown	4-5	12-20
7	Dumbbell skull crusher	4-5	12-20
8	Concentration curl	4-5	12-20

Workout 7: LISS

Take your workout outside and go rucking (hike with a loaded backpack or weighted vest) for two hours. Take breaks as required and remember to stay hydrated. Aim to carry 10-15% of your body weight for resistance. 

Check out our exercise library for step-by-step guides to the exercises in this program.

Closing Thoughts

21 days might not sound like a long time, but when you commit to exercising every day, it can be transformative! Stringing together so many back-to-back workouts will not just build muscle and strength while building fat, it will teach you the psychological skills you need to become a habitual, self-motivated exerciser.

Will the next three weeks be easy? Definitely not!

However, your efforts will be rewarded, and you’ll probably make more progress in 21 days than you’d normally make in six months.

What should you do on completion of this bootcamp? I suggest you enjoy a seven-day deload and then go back to a more moderate training program. Revisit this bootcamp the next time you need a progress boost.

Questions or comments? Please drop me a line below and I’ll get back to you ASAP!

---