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HIIT Blast — Workout 6

This 20-minute intermediate workout focuses on best cardio workout. Led by Natalia Gunnlaugs, it targets shoulders, core, quads with evidence-based exercises designed for women of all fitness levels.

Exercise Breakdown

18 exercises in Workout 6

Warm-up6 exercises
2m 15s
0:05
Warm-up: Arm Circles

“Really open up the arms”

shouldersarms
low
0:21
Warm-up: Torso Twists

“Just a little twist to the sides”

spinecore
low
0:31
Warm-up: Hinge with Arm Reach

“Engage your core, reach your arms up”

hamstringsshoulderscore
low
1:01
Warm-up: Good Mornings

“Trying to keep the chest open throughout”

hamstringsgluteslower back
low
1:26
Warm-up: Lunge with Twist

“Twist to the same direction as the knee that's forward”

quadsglutesspinehips
medium
1:51
Warm-up: Lunge Pulses

“Find that balance, lean forward, look down”

glutesquads
medium
Strength3 exercises
1m 29s
3:41
Ground to Overhead

“Similar to a deadlift, where we hinge from the hips”

full bodyshouldershamstrings
medium
5:10
Single Leg Reverse Lunge with Knee Drive

“Find some spot to look at for balance”

glutesquadscore
high
10:15
Reverse Lunge with Lateral and Front Raises

“Bring those dumbbells up to shoulder height”

shouldersquadsglutes
medium
Cardio7 exercises
5m 14s
3:10
Alternating Reverse Lunges with Knee Drive

“Knee up high, reaching towards the palm”

quadsglutescore
high
4:11
Side Plank with Mountain Climbers

“Keep the bum low”

coreshouldersarms
high
7:15
Ground to Overhead with Jump

“Bring the bum back”

full bodyquadsshoulders
high
8:00
Mountain Climbers

“Kick the knee towards the opposite elbow”

coreshoulderscardiovascular
high
9:30
Squat with Knee to Elbow Crunch

“Try to touch the knee each time”

quadsglutescore
medium
11:00
Burpees

“Make sure you bring the chest all the way down”

full bodychestarmsquads
high
14:30
Finisher: Burpee Tuck Jump with High Knees

“We're adding two high knees each time”

full bodycardiovascularcore
high
Cool-down2 exercises
59s
16:40
Cool-down: Downward Dog

“Chest pressing towards the knees”

hamstringsshoulderscalvesspine
low
17:11
Cool-down: Puppy Pose

“Stretching out those shoulders, the chest after those burpees”

shoulderschestupper back
low

Muscles Targeted

Primary

shoulderscorequads

Secondary

gluteshamstringsfull body

Equipment & Modifications

Equipment Needed

  • dumbbells
  • mat

Don't Have Equipment?

You can substitute with:

water bottlescanned goodsresistance bandsthick towelcarpet

Available Modifications

  • can do it bodyweight
  • use water bottles
  • add a little jump

Coaching Highlights from Natalia Gunnlaugs

“Twist to the same direction as the knee that's forward I tell every new client the same thing: if you can't feel the muscle working, slow down until you can. Speed is not the goal.”

Form

“Breathe. Don't hold your breath This is non-negotiable — I've seen the injury that happens when you skip this step, and it's not worth the two extra reps.”

Safety

“Stretching out those shoulders, the chest after those burpees Some days you show up and everything clicks. Other days it's a fight from the first rep. Both count.”

Motivation

“Natalia pushes hard but always gives you an escape hatch. She'll say 'keep going' in the same breath as 'modify if you need to.' That's not a contradiction — it's coaching.”

Form

Health Benefits

If your heart rate hasn't been above 'walking the dog' pace in months and you know it, this 20-minute session is where you start — I designed it for women who want cardiovascular conditioning without spending an hour on a treadmill. If you're in your 30s or 40s dealing with metabolic slowdown, weight creep, or that specific afternoon energy crash — HIIT addresses all three through the same mechanism. You'll need dumbbells, mat and the willingness to be uncomfortable for 45 seconds at a time.

Relevant For

back painbalancebone densitycardiovascularcore strengthfatigueflexibilityhip painknee painmetabolismpostureshoulder painstressweight gain

Frequently Asked Questions

What muscles does this HIIT workout target?

Your shoulders, core, quads take the biggest hit, with secondary work through glutes, hamstrings, full body. But here's what most people miss about hiit workouts: the primary target is your cardiovascular system, not individual muscles. A 2024 meta-analysis by Dupuit et al — found HIIT reduces visceral fat in perimenopausal women more effectively than steady-state cardio. The 18 exercises in this 20-minute session with Natalia Gunnlaugs are designed to keep your heart rate in the 80-90% zone for short bursts. That's where the metabolic magic happens. Your muscles are along for the ride — and they benefit too.

What equipment do I need for this workout?

You'll need: dumbbells, mat. Don't have these? water bottles, canned goods work as substitutes — I've coached women through this with filled water bottles and it works. The resistance is what matters, not the brand. Natalia Gunnlaugs shows form with standard equipment, but anything that adds load will do. Just make sure it's comfortable to grip — slippery objects and high-intensity moves don't mix. This pairs well with a core and cardio workout approach. This pairs well with a core strengthening exercises approach.

Is this workout suitable for beginners?

This is rated intermediate, so it assumes some baseline fitness. But Natalia Gunnlaugs offers modifications: can do it bodyweight; use water bottles. If you've been training consistently for 2-3 months, you're ready. If you're brand new, start with a beginner-level workout in this series and work up. Nobody benefits from ego-lifting into an intermediate session on day one. This pairs well with a high intensity workout for fat loss approach.

How long is this workout?

Approximately 20 minutes, including warm-up and cool-down. Natalia Gunnlaugs wastes zero time — 18 exercises, no standing around, no 3-minute rest periods. The ACSM recommends 150 minutes of moderate or 75 minutes of vigorous exercise per week. Two or three of these sessions gets you there. That's 40-60 minutes per week of actual exercise. The rest of your week is yours.

Are there modifications available?

For every exercise. Natalia Gunnlaugs cues modifications as they come up: can do it bodyweight; use water bottles; add a little jump — I'll say this once: using a modification is not failing. It's choosing the version that lets you maintain form for the entire set. A half-range pushup with a flat back beats a full-range pushup with a sagging spine every time. Pick the version where your technique stays clean.

How many calories does a HIIT workout burn?

The honest answer: it depends on your weight, fitness level, and actual effort. A 20-minute HIIT session typically burns 200-400 calories for a 140-170lb woman working at true high intensity. But here's what matters more than the calorie number: EPOC. Excess post-exercise oxygen consumption. Dupuit et al.'s meta-analysis found HIIT triggers metabolic elevation for up to 24 hours after the workout ends. So the calories you burn during the session are just the opening act. The real metabolic work happens while you're making dinner.

Is HIIT safe for women over 40?

Yes — with appropriate modification and a proper warm-up, which Natalia Gunnlaugs includes. A 2024 systematic review by Huynh et al — found aerobic exercise (including HIIT) significantly improves cardiovascular health in postmenopausal women with no increase in injury rates when progressed appropriately. The key phrase is 'progressed appropriately.' Start with the modification. Build up over 2-3 weeks. If you have joint issues, swap jumping for stepping. HIIT means high heart rate, not high impact. Those are two different things.

How often should I do HIIT workouts?

Two to three times per week, with at least one rest day between sessions. Your body needs 48 hours to recover from genuine high-intensity work. If you're doing HIIT every day, you're either not going hard enough or heading straight toward overtraining. Mandrup et al — demonstrated that three sessions per week was the sweet spot for improving insulin sensitivity in menopausal women. More wasn't better. Recovery is not laziness — it's where adaptation happens.

Related Workouts & Topics

About the Trainer

Natalia Gunnlaugs

Natalia Gunnlaugs

Cardio Trainer

From: HIIT Blast