By Coach Paul Warloski
Between long workdays, family commitments, and everything else life throws at us, it’s easy to feel like there’s no time for quality training.
But even if your schedule doesn’t allow for long endurance sessions, high-intensity interval training (HIIT) can help you maintain fitness, boost performance, and stay consistent — all in less time.
HIIT isn’t a shortcut; it’s a targeted, effective way to maximize limited training time to prepare you for your gravel or cyclocross race or your trail running race.
When done right, two or three short, intense sessions a week can significantly improve aerobic capacity, muscular endurance, and mental toughness.
What Is HIIT?
High-intensity interval training alternates short bursts of hard effort (typically 30 seconds to 4 minutes) with recovery periods.
The goal is to work at or near your VO₂max intensity, that level where breathing becomes labored, heart rate rises close to maximum, and you can only sustain the effort briefly.
HIIT challenges both your cardiovascular and muscular systems, leading to powerful adaptations in less time.
Research consistently shows that HIIT can improve VO₂max, mitochondrial density, and overall endurance performance, even when total training volume is reduced.
Examples of Time-Efficient HIIT Workouts
Whether you’re cycling, running, or doing a bodyweight session, these formats can deliver results:
1. Classic 30/30 Intervals
- 30 seconds at 90–100% of max effort
- 30 seconds easy spin or jog recovery
- Repeat 10–15 times
- Benefits: Builds VO₂max, mental resilience, and fatigue resistance
2. 4×4 Minute Intervals
- 4 minutes at ~90–95% of max HR (or RPE 8/10)
- 3 minutes recovery between intervals
- Repeat 4 times
- Benefits: Improves aerobic power and lactate threshold
3. Tabata-Style Session (cycling, running, or strength work)
- 20 seconds all-out effort
- 10 seconds rest
- Repeat 8 times for one 4-minute set
- Rest 2–3 minutes and repeat up to 3 sets
- Benefits: Boosts anaerobic capacity and aerobic efficiency in minimal time
For strength or mixed-modal HIIT, combine exercises like kettlebell swings, jump squats, burpees, or rowing sprints with short recoveries.
Maintain high intensity, keep the duration short, and ensure excellent form.
Don’t Overdo It — Two or Three Sessions a Week Is Enough
HIIT is powerful, but more isn’t better.
Each session carries a high recovery cost, both physiologically and neurologically. Muscles, connective tissue, and your nervous system need time to adapt.
For most athletes and busy professionals, two HIIT sessions per week is ideal, three if you’re fit, well-rested, and eating well.
Fill the rest of your week with Zone 2 aerobic work, mobility, yoga, and strength sessions to maintain balance and prevent burnout.
As exercise scientist Stephen Seiler puts it, elite endurance athletes typically follow an 80/20 model: about 80% of training time at low intensity, 20% high intensity.
The same principle applies even when you have limited time — just scale the volume, not the intensity mix.
What Results Can You Expect?
When you commit to consistent, quality HIIT training (two to three times weekly), you can expect:
- Improved VO₂max and aerobic power
- Higher lactate threshold (you can go harder, longer)
- Greater muscle efficiency and mitochondrial function
- Reduced perceived effort during moderate endurance sessions
- Improved time-to-exhaustion in short events (20–60 minutes)
These gains typically appear after 4–6 weeks of structured HIIT, especially when recovery and nutrition are optimized.
Fueling HIIT for Success
HIIT sessions demand glycogen, your body’s preferred high-octane fuel.
If you train fasted or under-fueled, you’ll struggle to hit the required intensity, limiting the benefits.
Pre-workout fuel:
- Eat a small carbohydrate-rich snack 30–60 minutes before: a banana, a slice of toast with honey, or an energy chew. I love pure maple syrup!
- Hydrate with water and electrolytes, especially if you train early or in the heat.
During longer HIIT sessions:
- For workouts lasting over 60 minutes, consider small carb intakes (30–60g/hour).
Post-workout recovery:
- Refuel with a mix of carbs and protein (3:1 ratio) within 30 minutes — like Greek yogurt with berries, a smoothie, or a recovery shake.
- Don’t forget hydration and sodium replenishment if you’ve sweated heavily.
Proper fueling doesn’t just support energy during the workout, it drives recovery, adaptation, and performance gains.
Three Things to Know About HIIT For Busy People
- HIIT is a time-efficient way to build endurance and strength when life gets busy — but it’s not a replacement for all aerobic work.
- Two to three sessions per week are plenty; recovery is when fitness grows.
- Fuel wisely before and after workouts to maximize performance and adaptation.
Final Thoughts
You don’t need endless hours to stay fit.
A few focused, high-quality HIIT sessions, paired with recovery and smart nutrition, can deliver real, measurable results.
If you’re not sure how to structure these sessions around your other training or how to balance intensity with recovery, schedule a call with Simple Endurance Coaching.
We’ll help you design a personalized, sustainable plan, even for the busiest weeks.
Paul Warloski is a:
- USA Cycling Level 1 Advanced Certified Coach
- RRCA Running Coach
- Training Peaks Level 2 Coach
- RYT-200 Yoga Instructor
- Certified Personal Trainer
- Certified Nutrition Advisor
