Instructions

Download our USER GUIDE as pdf.

Introduction

The Unipedal™ is a simple yet revolutionary training device designed for assisted one-legged pedaling, or unipedaling.

In exercises involving large muscle masses, like cycling, the heart and lungs often limit performance due to their oxygen delivery capacity. By reducing the muscle mass involved by half, the heart and lungs are no longer the limiting factor. As a result, your leg muscles can pedal at a higher mechanical and metabolic intensity, accelerating endurance adaptations that are otherwise unattainable with standard two-legged cycling.

During two-legged pedaling, the leg pushing in the downstroke reduces the strain on the muscles of the leg in the upstroke, which would otherwise fatigue quickly. The Unipedal™ connects between your bike’s handlebar and the foot of the pedaling leg. It uses a tension spring that stretches as you push down and then assists during the upward phase, creating a pedaling motion that closely mimics two-legged cycling — with only one leg working at a time.

In summary:

UNIPEDALING allows you to train more EFFECTIVELY, enabling your heart and lungs to focus on providing oxygen to ONE LEG AT A TIME.

Key Features

Mimics two-legged pedaling by providing upstroke assistance for extended unipedaling sessions.
User-friendly design that mounts in minutes, facilitates quick side switches, and is adjustable for spring tension and bike geometry.
Compatible with most bikes, trainers or ergometers, handlebars, pedals, and shoes.
Portable thanks to a compact, lightweight design and included storage case.
Affordable due to its simplicity.
Modular design that allows you to build your own setup and replace worn-out parts.

Mounting and Setup

Follow these steps carefully before your first ride.

Preparation

Secure your bike on a trainer or use a stationary bicycle.
Ensure you are wearing cycling shoes that click into the pedals or have toe-clips.

Attach to Foot

Clipless pedals: Fasten the foot strap securely around your shoe, with the carabiner opening facing the front of the foot and the strap to the outside.
Toe clips: Position the toe clip carabiner centrally on the toe clip strap, with the opening facing forward. Slide your foot into the toe clip, tighten firmly, and secure, as the spring will pull on the toe clip during the upstroke.

Attach to Handlebar

Loop the straps around the handlebar, positioning one on each side of the middle line, handlebar clamp, or stem. Tighten the strap to prevent sliding when the spring is tensioned. Secure it as close to the middle as possible to minimize twisting torque when the spring pulls on the handlebar.

Ensure a smooth line from handlebar to foot without touching the knee cap. Adjust the handlebar height and reach as needed, typically by lowering and/or moving it forward.

Adjust the Starting Tension

The spring features an internal “overtension cord” to prevent overstretching. To optimize assistance over both the “top dead center” (TDC) and “bottom dead center” (BDC) of the pedal stroke, adjust the spring so the internal “overtension cord” is almost fully stretched when the pedal is furthest from the handlebar.

Too loose: Pedaling assistance is suboptimal, especially over the TDC, and the spring may hang or slap, leading to potential injury or bike damage.
Too tight: The “overtension cord” will reach its maximum and stop the pedal stroke.

⚠️ Warning: If the “overtension cord” is forced beyond its stop, the handlebar strap buckle is designed to break first, preventing damage to the bicycle.

With optimal spring use, you should experience a natural, circular pedal stroke with assistance over both TDC and BDC. However, as the spring is maximally stretched through the BDC, this phase of the pedal stroke might feel jerky due to high spring tension. This sensation typically improves after a few familiarization sessions of unipedaling.

Remember ☝🏻

The correct setup makes unipedaling feel similar enough to two-legged cycling to enable efficient training, but it is not exactly the same.

Safety and Basic Use

⚠️ Unipedaling is physically demanding. Consult a medical doctor before using unipedaling as a training modality. When starting, take time to adapt before engaging in long or intense sessions.

⚠️ Warning: Never use the Unipedal™ outdoors or on a moving bike. It is designed exclusively for stationary trainers and ergometers.

Before You Start

Inspect for excessive wear or damage to the bicycle or The Unipedal™.
Ensure the spring and straps are properly secured.

⚠️ Returns, replacement & recycling: If the Unipedal™ breaks before its expected lifetime, contact returns@unipedaling.com to determine if you're eligible for a free replacement. Please recycle broken parts in accordance with your country's laws and recycling system.

During Training

Warm up for at least 5–10 minutes using two-legged pedaling without assistance before starting unipedaling.
Always keep at least one hand on the handlebar for balance. If your bike and trainer allow the front wheel to move, grip the handlebar on the outside to prevent twisting due to the spring's pulling force.
Maintain a smooth, controlled cadence within the 70–100 rpm range. Keep your upper body relaxed and let your leg do the work. Focus on pushing during the downstroke and maintaining pressure through the TDC and BDC.
The non-pedaling leg should hang straight down, ensuring the pedal on that side doesn’t cause injury. For additional comfort, consider using a foot rest strap or a stool to rest the non-pedaling leg.
Stop immediately if the spring or straps loosen unexpectedly.

After Training

Cool down for 5–10 minutes with two-legged pedaling (without assistance).
Clean regularly by rinsing with lukewarm water and soap or mild detergent.

Training with the Unipedal™ Performance

Unipedaling is a powerful tool for improving aerobic adaptations in the pedaling muscles, thanks to the heart and lungs focusing on only one leg. This concept, known as aerobic hyperpower, is most effective when training with a cycling power meter, to monitor training intensity and left/right balance. Below are training principles and example sessions for performance-focused athletes.

Training Principles

Goal: To enhance each leg’s capability to perform at a higher power output than would be possible when using both legs simultaneously.
Frequency: 1–4 sessions per week.
Volume (unipedaling) per session: 10–60 minutes.
Intensity: Unipedaling is most effective with high intensity, approximately 100–150% of threshold, where performance is primarily limited by oxygen delivery to the working muscles.
Structure: Typically performed in 3–10 minute intervals or as single blocks of 10–30 minutes. It’s generally recommended to train one leg fully before switching, maximizing the hyperemic (blood flow) response. However, for convenience, switching legs between intervals is also effective.
Integration: Unipedaling can be a standalone session or part of your indoor cycling program, and can be combined with outdoor cycling or other sport-specific sessions.
Progression: Gradually increase intensity, interval duration, and total session volume; avoid increasing all at once.

⚠️ Warning: Unipedaling imposes high metabolic stress on the muscles. Gradually increase training load to avoid local overtraining effects, even if the heart and lungs don’t feel maximally strained.

As with any new training modality, there is a learning curve. Although unipedaling mimics two-legged pedaling better than non-assisted single-leg pedaling, it is not identical. Pay attention to sensations, effort, and fatigue patterns, aiming for progression over time.

Here are some guidelines:

With increased blood flow to a single leg, you might feel a “thick” or “big” leg sensation. Though uncomfortable initially, this usually decreases with each session and progresses as the body adapts by dilating blood vessels and capillaries in the trained muscles.
During early sessions or when ramping up intensity, you might experience pain or high effort sensations in some muscles. Train within your limits of effort and discomfort, but push your limits. If the discomfort is more pain than effort, rest for a few days before gradually resuming unipedaling.

💡 PRO TIP: Before incorporating unipedaling into your routine, try a few sessions of traditional single-leg pedaling without assistance. This common cyclist drill enhances pedaling technique by forcing the rider to lift the leg and drive the pedal throughout the stroke, especially the upstroke. Pedaling for 30–120 seconds with one leg before switching and repeating for 4–10 minutes per leg will prepare your muscles for unipedaling.

Example Workouts

Familiarization Session

Goal: Allow muscles to adapt to unipedaling dynamics and adjust to the relationship between intensity, effort, duration, and fatigue.

Warm up 10–15 minutes with two-legged pedaling.
2 x 4 minutes of unipedaling per leg (alternate right and left leg) at a challenging but manageable effort.
- Focus on smooth motion with a strong downstroke, paying extra attention to driving the pedal through TDC and BDC, while allowing the spring to assist the upstroke.
Rest 2 minutes, spin easily, and switch sides between intervals.
Cool down with easy two-legged pedaling for at least 5 minutes.

Maximal Aerobic Power (MAP) Intervals

Goal: Increase maximal aerobic capacity in pedaling muscles.

Warm up 10–20 minutes with two-legged pedaling, including a few < 1 minute higher-intensity efforts.
1-4 x 5 minutes of unipedaling per leg at > 110% of two-legged threshold (FTP or critical power) divided by two.
- Focus on smooth, consistent motion throughout the pedal stroke and equal power production (see L2R) in both legs.
Rest 5 minutes and spin easily if performing all intervals on one leg before switching; or 1 minute rest, spin easily and switch sides between intervals if alternating legs.
Cool down with easy two-legged pedaling for at least 5 minutes.

Supra-Threshold Endurance Block

Goal: Enhance threshold power capacity and fatigue resistance in pedaling muscles.

Warm up 10–20 minutes with two-legged pedaling, including a few < 1 minute higher-intensity efforts.
Perform one block of 15–30 minutes for each leg at 100–110% of two-legged threshold (FTP or critical power) divided by two. Use rest periods of < 1 minute within this block, e.g., 2.5 minutes work and 30 seconds rest or 4 minutes work and 1 minute rest.
- Focus on maintaining a steady pace and staying relaxed when local fatigue sets in, ensuring equal (see L2R) power production in both legs.
Rest 5–10 minutes and spin easily with two legs, possibly including a short “re-warm-up,” before starting the effort on the second leg.
Cool down with easy two-legged pedaling for at least 5 minutes.

Tabata Interval Session

Goal: Efficiently maximize training effect in the shortest possible time.

Warm up 5–10 minutes with two-legged pedaling, including 1–2 x < 1 minute higher-intensity efforts.
Perform a set of Tabata intervals: 8 x 20-second work intervals of unipedaling with 10 seconds of rest between. Aim for > 125% of two-legged threshold (FTP or critical power) divided by two during the 20-second work interval. During the 10-second rest interval, you can place the foot of the non-working leg back on the pedal to pedal lightly with two legs.
Rest 2 minutes and spin easily after 8 x 20 seconds for the first leg, before switching to the other leg and performing the same.
Cool down with easy two-legged pedaling for at least 5 minutes.

Combining with Two-Legged Cycling

Unipedaling complements sessions focusing on two-legged pedaling, whether intervals, drills, or low-intensity volume.

BEFORE: Perform unipedaling first in the session, leaving enough energy for intense two-legged training or a long low-intensity ride directly afterward.
AFTER: Engage in high-intensity, technical, or long-duration low-intensity training before finishing with a unipedaling session, e.g., 3 x 5 minutes two-legged HIT intervals followed by 2 x 5 minutes per leg at the same power as the two-legged intervals divided by two to accumulate more time at that muscular intensity, but at a lower strain for the heart and lungs.

Combining with Other Types of Training

Unipedaling is an effective training method for sports requiring high muscular endurance in the legs, such as ice hockey, alpine skiing, speed skating, and CrossFit. When integrating unipedaling into non-cycling sports training, we generally recommend performing unipedaling AFTER the sport-specific training.

Injury Rehabilitation

Unipedaling is beneficial when an athlete is limited in one leg, such as after injury or surgery.

Independent limb training: Athletes can train the healthy leg at high intensity to maintain cardiovascular fitness and benefit from "cross-education" effects, where neural adaptations in the trained limb help maintain strength in the injured limb.
Reduced cardiopulmonary load: For athletes recovering from illness or with respiratory limitations, unipedaling allows for more muscular work with lower load on heart and lungs.

Altitude

Unipedaling is particularly effective for athletes living or training at altitudes above 1200 meters (4000 feet) where oxygen availability is limited in the “thin air.” Unipedaling compensates for reduced oxygen availability at altitude by increasing blood flow to the active leg by 30–90% compared to double-leg pedaling, ensuring the same amount of oxygen reaches the working muscles, allowing for sea-level power production.

Monitoring Progress

We highly recommend using a bicycle or additional equipment that provides pedaling power output (W) while unipedaling. Track these progression metrics over time:

Improvement in power output per leg at the same perceived exertion (PE) or heart rate (HR).
More equal power output between the left and right leg.

Without power measurement, you may notice a decrease in breathing frequency (BF) and/or an increase in heart rate (HR) for a given perceived exertion (PE).

2-2-1

Initially, when not yet adapted to unipedaling, the power output per leg might be lower compared to half the power of two-legged pedaling with the same effort. Test this with the following procedure:

Warm up for 15–30 minutes, perform a maximal 5–10 minute effort with two legs, then cool down for at least 10 minutes.
Allow at least 48 hours of recovery after the two-legged test.
Warm up for 15–30 minutes, perform the same duration maximal effort of unipedaling with the first leg. Allow for 10–20 minutes of rest, easy two-legged pedaling, and a short “re-warm-up” before testing the second leg. Cool down with at least 10 minutes of easy two-legged pedaling.

Perform both test sessions with the same bike and power meter (calibrated according to manufacturer instructions) and under the same conditions (time of day, room temperature, last meal, etc.).

Subtract half the power from the two-legged test from the power from your best leg during unipedaling. Then divide this number by half the power from the two-legged test and multiply by 100. This is your 2-2-1 score. When this score is positive, you know you are tapping into the aerobic hyperpower that makes unipedaling a powerful training stimulus.

⚠️ It is not necessarily required to reach hyperpower, measured with a power meter, which reflects external power output. Research has shown that unipedaling with a spring device leads to lower pedaling efficiency. This means that for a given internal metabolic load, less is converted to mechanical power at the pedals. However, it is the internal metabolic load in the working muscles, often measured as VO2, that primarily stimulates training adaptations. The internal load will be sufficient if the unipedaling effort is high, often resulting in a high heart rate since only half as much pedaling muscle mass is involved.

L2R

It is common for the left and right legs to have different work capacities, often reflected in discrepancies in power output, heart rate, and perceived effort between legs. This left-right imbalance is generally correlated with the dominant versus non-dominant leg.

Equal power output and work capacity between legs are beneficial for performance, comfort, and injury prevention. Therefore, monitor left-right leg balance and work towards minimizing discrepancies.

⚠️ If the difference in power production exceeds 3% between legs, let the leg with the lowest capacity guide the training to ensure the “weaker” leg is not overstrained and has a chance to catch up.