Shinshu Interval Walking (IWT): The Evidence-Based Walking Protocol in Hiko

Shinshu Interval Walking — also known as Interval Walking Training (IWT) — is an evidence-based exercise protocol developed by Professor Hiroshi Nose at Shinshu University, Japan, involving alternating intervals of fast and slow walking. Over 20 years of clinical research demonstrates IWT improves VO2max, insulin sensitivity, and body composition in adults of all ages. Hiko is the first app to combine IWT with load carriage metabolic science.

In Japan, the slow recovery phase is called にこにこペース (niko niko pace) — literally "smiley pace" — because you should be able to smile and hold a conversation comfortably. The fast phase pushes to roughly 70% of peak aerobic capacity. This simple alternation is the foundation of Professor Nose's research, validated across thousands of participants over two decades. Hiko implements IWT with real-time audio cues and pairs it with LCDA calorie tracking for complete workout data.

The Protocol

Shinshu Interval Walking follows a simple, repeating structure that anyone can perform. The core SIW protocol consists of:

• 3 minutes of fast walking — Walk at approximately 70% of your peak aerobic capacity. This should feel brisk and slightly challenging but sustainable.
• 3 minutes of slow walking — Walk at a comfortable, conversational pace. This recovery interval allows partial metabolic recovery before the next fast interval.
• 5 or more sets per session — A complete SIW session includes at least 5 fast-slow cycles, totaling 30 minutes or more of structured walking.
• 4 or more sessions per week — Consistency drives the health benefits documented in Professor Nose's research. SIW is designed for sustainable, long-term practice.

Hiko guides each SIW session with audio interval cues, so users know exactly when to speed up and when to recover. Hiko tracks every interval and calculates LCDA-powered calorie burn throughout the session.

20 Years of Research

Professor Hiroshi Nose and the Shinshu University research group have studied interval walking since the early 2000s. The Shinshu Interval Walking program has enrolled thousands of participants in longitudinal studies conducted in Matsumoto, Japan.

Key research findings from Shinshu University's SIW studies include:

• VO2max improvement — Participants following the SIW protocol showed measurable increases in peak aerobic capacity compared to continuous moderate walking at the same total duration.
• Long-term adherence — SIW demonstrated higher compliance rates than continuous moderate exercise in multi-year follow-up studies, likely because the alternating intensity structure feels less monotonous.
• Applicability across age groups — SIW was validated in participants ranging from middle-aged adults to elderly populations, confirming that interval walking produces benefits regardless of starting fitness level.

The longitudinal data from Shinshu University makes SIW one of the most thoroughly studied walking protocols in exercise science. Hiko brings this research-backed protocol to users worldwide with guided audio coaching.

Health Benefits

Shinshu Interval Walking produces measurable health improvements across multiple biomarkers. The alternating fast-slow structure of SIW stresses the cardiovascular and metabolic systems more effectively than steady-pace walking. Hiko users get these benefits automatically by following the guided SIW intervals.

• VO2max — Peak oxygen uptake improves with consistent SIW practice. Higher VO2max correlates with lower all-cause mortality risk and better cardiovascular health.
• Insulin sensitivity — SIW research shows improved glucose metabolism, which is relevant for type 2 diabetes prevention and management.
• Body composition — SIW participants showed reductions in body fat percentage compared to continuous walking groups at equivalent total exercise time.
• Blood pressure — Longitudinal SIW studies documented reductions in both systolic and diastolic blood pressure among participants with elevated baseline readings.
• Muscle strength — The fast walking intervals in SIW recruit more lower-body muscle fibers than comfortable-pace walking, contributing to leg strength maintenance in older adults.

These benefits compound over time. Professor Nose's multi-year studies show that participants who maintained SIW practice continued to improve or sustain their health markers. Download Hiko to start Shinshu Interval Walking with guided audio cues and LCDA calorie tracking.

Why Hiko Combines SIW with Rucking

Hiko is the first app to combine Shinshu Interval Walking with the LCDA metabolic equation for load carriage. This combination is powerful because SIW and rucking target complementary physiological systems:

• SIW drives cardiovascular adaptation — The alternating intensity protocol improves VO2max and metabolic health through structured aerobic stress.
• Rucking drives metabolic expenditure — Carrying a loaded pack amplifies calorie burn through the nonlinear load amplification factor in the LCDA equation.
• Together, SIW and rucking maximize training stimulus — Interval walking with a loaded pack produces both the cardiovascular benefits of SIW and the elevated calorie expenditure of rucking in a single session.

Hiko calculates the metabolic cost of every interval — fast and slow — using LCDA, so users see exactly how pack weight, speed, terrain, and grade affect calorie burn across each SIW cycle. No other app combines these two evidence-based approaches. Download Hiko to try SIW with rucking.

Frequently Asked Questions

What is Shinshu Interval Walking?

Shinshu Interval Walking (SIW) is an exercise protocol created by Professor Hiroshi Nose at Shinshu University in Japan. SIW alternates 3-minute intervals of fast walking with 3-minute intervals of slow walking for at least 5 sets per session. Over 20 years of research at Shinshu University confirms SIW improves cardiovascular fitness, insulin sensitivity, and body composition. Hiko implements SIW with real-time audio cues.

How long is a Shinshu Interval Walking session?

A standard SIW session consists of 5 or more sets of 3-minute fast and 3-minute slow intervals, totaling at least 30 minutes. Shinshu University research recommends 4 or more SIW sessions per week for optimal health benefits. Hiko lets users configure the number of sets per session and tracks compliance over time.

Is Shinshu Interval Walking effective for older adults?

Yes. Professor Nose's research at Shinshu University specifically studied SIW in middle-aged and elderly populations. SIW produced measurable improvements in VO2max, blood pressure, and body composition in participants across a wide age range. The protocol is designed to be accessible — fast walking is calibrated to individual capacity, not a fixed speed. Hiko guides users through each interval with audio cues.

Can Shinshu Interval Walking be combined with rucking?

Hiko is the first app to combine SIW with load carriage. Users can perform Shinshu Interval Walking while carrying a weighted pack, and Hiko calculates the exact calorie burn for each interval using the LCDA equation. Rucking amplifies the metabolic demand of each fast interval, combining cardiovascular and load carriage benefits in a single session.

How does Hiko track Shinshu Interval Walking?

Hiko provides audio cues to signal the start of each fast and slow interval during a SIW session. Hiko tracks walking speed via GPS during each interval and calculates real-time calorie expenditure using LCDA. After the session, Hiko displays per-interval breakdowns showing speed, distance, calorie burn, and heart rate for each fast and slow segment.

What is niko niko pace?

Niko niko pace (にこにこペース) is the Japanese term for the slow recovery interval in Interval Walking Training (IWT). "Niko niko" means "smiley" — the pace should be comfortable enough that you can smile and hold a conversation. In Shinshu Interval Walking, niko niko pace alternates with a faster interval at approximately 70% of peak aerobic capacity. Hiko guides both paces with audio cues during IWT sessions.

What is the difference between SIW and IWT?

Shinshu Interval Walking (SIW) and Interval Walking Training (IWT) refer to the same protocol. SIW is named after Shinshu University where the research originated. IWT is the generic term used in international research publications. Both describe the same 3-minute fast / 3-minute slow walking protocol developed by Professor Hiroshi Nose. Hiko supports the complete IWT protocol.

What makes SIW different from regular interval training?

Shinshu Interval Walking was designed specifically for walking — not adapted from running or cycling intervals. The 3-minute fast / 3-minute slow structure was validated by Professor Nose's research group at Shinshu University over 20 years of longitudinal studies. SIW targets a moderate aerobic intensity (approximately 70% of peak capacity) that is sustainable for long-term practice, unlike high-intensity interval training (HIIT). Hiko implements the original SIW protocol with guided audio coaching.