Effects of Contemporary Cycling Saddle Designs on Penile Transcutaneus Oxygen and Carbon Dioxide Levels in Elite Road Cyclists Riding on a Stationary Trainer (EC-SADDLE)

Aim of this research is to compare novel 3D printed cycling saddle with the bestselling saddles from two major cycling manufacturers in terms of effects on penile blood gasses and update these findings on current style of racing cycling saddles.

Study Overview

• Status: Completed
• Conditions: Healthy; Blood Gas Monitoring, Transcutaneous; Cyclists; Penile Numbness
• Intervention / Treatment: Device: Biothesiometry; Device: Bike Fitting; Device: Transcutaneous blood gas monitoring; Device: Cycling on a home trainer; Device: Heart rate monitoring; Device: Velomotrik smart cover BT

Detailed Description

The aim of this research is to investigate whether Posedla's 3D printed and custom-made prototype bicycle saddle Joyseat (Posedla s.r.o., Varnsdorf, Czech Republic) provide a benefit in terms of increased penile blood flow compared to the best-selling saddles from two major bicycle manufacturers. The method chosen to measure blood flow, which is commonly used in studies of this type, is referred to as transcutaneus blood gas monitoring. Measurement of TcPO2 and TcPCO2 in cyclists will be performed while riding on a cycling trainer using Radiometer TCM5 Flex (Radiometer Medical ApS, Brønshøj, Denmark) and a tc 84 electrode placed on the glans penis. Prior to the actual penile blood flow measurements, the sensitivity level of the n. pudendus (n. dorsalis penis) will be verified using biothesiometer (Bio Medical Instruments Co., Newbury, Ohio, USA), which is again commonly used in studies of this type. The pressure of the riders contact surfaces on the saddle will be evaluated with Velometrik SmartCover BT pressure mat (Velometrik GmbH, Neukieritzsch, Germany). The Wahoo KICKR Bike (Wahoo Fitness, LLC., Atlanta, Georgia, United States of America) will be used in the study, which, in addition to the possibility of individual seating adjustment, also allows to record the cyclists power and heart rate using a chest strap. The cyclists position on the bike will be measured and evaluated by infrared sensors and Retül technology (Specialized Bicycle Components, Inc., Morgan Hill, California, USA). The test will be performed using the described instrumentation in the Applied Kinesiology Laboratory at Charles University in Prague, Faculty of Physical Education and Sports and will involve riding 3x 10 minutes with 5 minutes rest in between intervals on the cycle trainer at 65-85% of the cyclists maximum individual heart rate during one visit. All measurement methods and devices are non-invasive and painless. The choice of instruments was based on their use in previously published studies of similar type and on their quality, i.e., the parameters of validity, reliability, sensitivity, specificity and availability.

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Czechia
  • Prague, Czechia, 162 52
    • Charles University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Study Population

Participants in the study will be deliberately approached and will in all cases be experienced or competitive cyclists with an annual mileage of over 7 000 km (maximum 28 000 km). Subjects will be recruited from a group of riders who already use a customised Joyseat saddle in their sporting career and the research group will be supplemented by professional cyclists from teams who have the option of having customised saddles made for their riders.

Description

Inclusion Criteria:

• gender: male, age: 18-45 years, discipline: road cycling, annual mileage: more than 14000 km (Tier 3-4)

Exclusion Criteria:

• Participants other than male, diagnosed with erectile dysfunction, acute or chronic back pain, acute (especially infectious) illness or injury, and in recovery from illness or injury are not eligible for inclusion in the research

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Group 1; Order of saddle testing: Joyseat saddle - Specialized Power saddle - Fizik Tundra M5 saddle	Device: Biothesiometry; Biothesiometry using Biothesiometer (Bio Medical Instrument Co, Ohio, United States of America), placed on glans penis and second finger of nondominant hand.; Other Names: Neurothesiometer; Device: Bike Fitting; Setting standardized posture of the rider on the bike using Retül technology (Retül, Specialized Bicycle Components Inc., Boulder, Colorado, United States of America); Device: Transcutaneous blood gas monitoring; Penile oxygen pressure using TCM5 Flex and tc84 electrode (Radiometer Medical ApS, Brønshøj, Denmark) placed on glans penis.; Device: Cycling on a home trainer; Riding a static bike Wahoo Bike (Wahoo Fitness LLC, Atlanta, Georgia, United States of America) for 3x 10 minutes in Zone 3 (Andy Coggan methodology) calculated from each individual subjects self reported Functional Threshold Power.; Device: Heart rate monitoring; Measuring heart rate using Wahoo TICKR chest strap (Wahoo Fitness LLC, Atlanta, Georgia, United States of America); Device: Velomotrik smart cover BT; Saddle pressure measurement, mean and max saddle pressure, saddle pressure distribution. (Velometrik GmbH, Neukieritzsch, Germany).
Active Comparator: Group 2; Order of saddle testing: Joyseat saddle - Fizik Tundra M5 saddle - Specialized Power saddle	Device: Biothesiometry; Biothesiometry using Biothesiometer (Bio Medical Instrument Co, Ohio, United States of America), placed on glans penis and second finger of nondominant hand.; Other Names: Neurothesiometer; Device: Bike Fitting; Setting standardized posture of the rider on the bike using Retül technology (Retül, Specialized Bicycle Components Inc., Boulder, Colorado, United States of America); Device: Transcutaneous blood gas monitoring; Penile oxygen pressure using TCM5 Flex and tc84 electrode (Radiometer Medical ApS, Brønshøj, Denmark) placed on glans penis.; Device: Cycling on a home trainer; Riding a static bike Wahoo Bike (Wahoo Fitness LLC, Atlanta, Georgia, United States of America) for 3x 10 minutes in Zone 3 (Andy Coggan methodology) calculated from each individual subjects self reported Functional Threshold Power.; Device: Heart rate monitoring; Measuring heart rate using Wahoo TICKR chest strap (Wahoo Fitness LLC, Atlanta, Georgia, United States of America); Device: Velomotrik smart cover BT; Saddle pressure measurement, mean and max saddle pressure, saddle pressure distribution. (Velometrik GmbH, Neukieritzsch, Germany).
Active Comparator: Group 3; Order of saddle testing: Specialized Power saddle - Fizik Tundra M5 saddle - Joyseat saddle	Device: Biothesiometry; Biothesiometry using Biothesiometer (Bio Medical Instrument Co, Ohio, United States of America), placed on glans penis and second finger of nondominant hand.; Other Names: Neurothesiometer; Device: Bike Fitting; Setting standardized posture of the rider on the bike using Retül technology (Retül, Specialized Bicycle Components Inc., Boulder, Colorado, United States of America); Device: Transcutaneous blood gas monitoring; Penile oxygen pressure using TCM5 Flex and tc84 electrode (Radiometer Medical ApS, Brønshøj, Denmark) placed on glans penis.; Device: Cycling on a home trainer; Riding a static bike Wahoo Bike (Wahoo Fitness LLC, Atlanta, Georgia, United States of America) for 3x 10 minutes in Zone 3 (Andy Coggan methodology) calculated from each individual subjects self reported Functional Threshold Power.; Device: Heart rate monitoring; Measuring heart rate using Wahoo TICKR chest strap (Wahoo Fitness LLC, Atlanta, Georgia, United States of America); Device: Velomotrik smart cover BT; Saddle pressure measurement, mean and max saddle pressure, saddle pressure distribution. (Velometrik GmbH, Neukieritzsch, Germany).
Active Comparator: Group 4; Order of saddle testing: Specialized Power saddle - Joyseat saddle - Fizik Tundra M5 saddle	Device: Biothesiometry; Biothesiometry using Biothesiometer (Bio Medical Instrument Co, Ohio, United States of America), placed on glans penis and second finger of nondominant hand.; Other Names: Neurothesiometer; Device: Bike Fitting; Setting standardized posture of the rider on the bike using Retül technology (Retül, Specialized Bicycle Components Inc., Boulder, Colorado, United States of America); Device: Transcutaneous blood gas monitoring; Penile oxygen pressure using TCM5 Flex and tc84 electrode (Radiometer Medical ApS, Brønshøj, Denmark) placed on glans penis.; Device: Cycling on a home trainer; Riding a static bike Wahoo Bike (Wahoo Fitness LLC, Atlanta, Georgia, United States of America) for 3x 10 minutes in Zone 3 (Andy Coggan methodology) calculated from each individual subjects self reported Functional Threshold Power.; Device: Heart rate monitoring; Measuring heart rate using Wahoo TICKR chest strap (Wahoo Fitness LLC, Atlanta, Georgia, United States of America); Device: Velomotrik smart cover BT; Saddle pressure measurement, mean and max saddle pressure, saddle pressure distribution. (Velometrik GmbH, Neukieritzsch, Germany).
Active Comparator: Group 5; Order of saddle testing: Fizik Tundra M5 saddle - Joyseat saddle - Specialized Power saddle	Device: Biothesiometry; Biothesiometry using Biothesiometer (Bio Medical Instrument Co, Ohio, United States of America), placed on glans penis and second finger of nondominant hand.; Other Names: Neurothesiometer; Device: Bike Fitting; Setting standardized posture of the rider on the bike using Retül technology (Retül, Specialized Bicycle Components Inc., Boulder, Colorado, United States of America); Device: Transcutaneous blood gas monitoring; Penile oxygen pressure using TCM5 Flex and tc84 electrode (Radiometer Medical ApS, Brønshøj, Denmark) placed on glans penis.; Device: Cycling on a home trainer; Riding a static bike Wahoo Bike (Wahoo Fitness LLC, Atlanta, Georgia, United States of America) for 3x 10 minutes in Zone 3 (Andy Coggan methodology) calculated from each individual subjects self reported Functional Threshold Power.; Device: Heart rate monitoring; Measuring heart rate using Wahoo TICKR chest strap (Wahoo Fitness LLC, Atlanta, Georgia, United States of America); Device: Velomotrik smart cover BT; Saddle pressure measurement, mean and max saddle pressure, saddle pressure distribution. (Velometrik GmbH, Neukieritzsch, Germany).
Active Comparator: Group 6; Order of saddle testing: Fizik Tundra M5 saddle - Specialized Power saddle - Joyseat saddle	Device: Biothesiometry; Biothesiometry using Biothesiometer (Bio Medical Instrument Co, Ohio, United States of America), placed on glans penis and second finger of nondominant hand.; Other Names: Neurothesiometer; Device: Bike Fitting; Setting standardized posture of the rider on the bike using Retül technology (Retül, Specialized Bicycle Components Inc., Boulder, Colorado, United States of America); Device: Transcutaneous blood gas monitoring; Penile oxygen pressure using TCM5 Flex and tc84 electrode (Radiometer Medical ApS, Brønshøj, Denmark) placed on glans penis.; Device: Cycling on a home trainer; Riding a static bike Wahoo Bike (Wahoo Fitness LLC, Atlanta, Georgia, United States of America) for 3x 10 minutes in Zone 3 (Andy Coggan methodology) calculated from each individual subjects self reported Functional Threshold Power.; Device: Heart rate monitoring; Measuring heart rate using Wahoo TICKR chest strap (Wahoo Fitness LLC, Atlanta, Georgia, United States of America); Device: Velomotrik smart cover BT; Saddle pressure measurement, mean and max saddle pressure, saddle pressure distribution. (Velometrik GmbH, Neukieritzsch, Germany).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pO2_change_point	Parameter pO2_change_point is the time from start of TcPO₂ measurement to the identified change point, determined within the 50-400 s interval as the transition between the fitted initial linear trend and the subsequent linear trend in TcPO₂	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_change_point	Parameter pCO2_change_point is the time from start of TcPCO₂ measurement to the identified change point, determined within the 200-550 s interval as the transition between the fitted initial linear trend and the subsequent linear trend in TcPCO₂	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pO2_start	The value of the fitted trend at time 0 in TcPO₂ measurement.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_decline	The slope of the fitted trend of decline in TcPO₂ after initial 20s.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_end	The slope of the second fitted trend after pO2_change_point in TcPO₂ measurement.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_part1	The average value of TcPO₂ measurements in the first 20 s segment.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_part2	The average value of TcPO₂ measurements for the second segment, from 21 s to the trend pO2_change_point.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_part3	The average value of TcPO₂ measurements for the third segment after pO2_change_point.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_mean	The average of all TcPO₂ measurements in one interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_median	The median of all TcPO₂ measurements in one interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_start	The value of the fitted trend at time 0 in TcPCO₂ measurement.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_incline	The slope of the fitted trend of increase in TcPCO₂ in the first segment before pCO2_change_point	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_end	The slope of the fitted trend in TcPCO₂ in the second segment after pCO2_change_point.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_part1	The average value of TcPCO₂ measurements in the first segment before pCO2_change_point.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_part2	The average value of TcPCO₂ measurements in the second segment after pCO2_change_point.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_mean	The average of all TcPCO₂ measurements in one interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_median	The median of all TcPCO₂ measurements in one interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
logratio_11_8	The logarithmic value of the ratio of the load on the front and rear parts of the saddle, where the saddle is divided in a ratio of 11:8 longitudinally.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
PERI	Pressure value in the predefined perineal area with an area of 44 cm² in front of the ischial tuberosity maxima.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
modPSRG/F	Vibrotactile thresholds were measured at the volar distal phalanx of the non-dominant hand and midline of the glans penis. The probe was placed perpendicular without additional pressure. Voltage was gradually increased until the first sensation was reported, then increased further and slowly decreased until sensation was lost. Upper and lower thresholds were recorded three times per site, averaged, and used to calculate the modified Penile Sensitivity Ratio Glans/Finger via the following formula. Average of the three glans upper+lower threshold values divided by the average of the three finger upper+lower threshold values.	A baseline testing at the beginning of the testing protocol lasting around 5 minutes.
CVdrift	The percentage of cardiovascular drift calculated as a ratio between average Power and average Heart Rate between the first and second part of the 10-minute interval. ((P1/HR1) - (P2/HR2))/(P1/HR1) * 100 where: P1 - Average Power from first half part of the workout P2 - Average Power from second half part of the workout HR1 - Average Heart Rate from first half part of the workout HR2 - Average Heart Rate from second half part of the workout	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
Bike Fit parameters	Bike Fit values as recorded by Retül V7 System. KOPS - Knee Over Pedal Spindle - The fore/aft offset of the knee marker relative to the pedal spindle at 3 o'clock in the pedal stroke (90° in the downstroke) MKF - Maximum Knee Flexion - Maximum flexion of the knee joint at any point in the pedal stroke defined by the line connecting hip and knee markers and the line connecting knee and ankle markers MKE - Maximum Knee Extension - Maximum extension of the knee joint at any point in the pedal stroke defined by the line connecting hip and knee markers and the line connecting knee and ankle markers SAW - Shoulder Angle to Wrist - The angle of the shoulder joint defined as the angle at intersection of the line connecting hip and shoulder markers, and the line connecting wrist and shoulder markers BA - Back Angle - The angle of the back relative to the horizon defined by the hip and shoulder marker	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_start	Mean of first 12s of TcPO₂ measurements in each 10 minute interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pO2_end	Mean of last 12s of TcPO₂ measurements in each 10 minute interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_start	Mean of first 12s of TcPCO₂ measurements in each 10 minute interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).
pCO2_end	Mean of last 12s of TcPCO₂ measurements in each 10 minute interval.	During a single laboratory visit consisting of three 10-minute cycling intervals with three 5-minute pause time in between cycling intervals (total assessment time approximately 45 minutes).

Collaborators and Investigators

• Sponsor: Milan Martínek
• Investigators: Principal Investigator: Milan Martínek, Mgr., Ph.D., Charles University, Czech Republic

Study record dates

Study Major Dates

• Study Start (Actual): April 21, 2023
• Primary Completion (Actual): May 14, 2023
• Study Completion (Actual): May 14, 2023

Study Registration Dates

• First Submitted: April 21, 2023
• First Submitted That Met QC Criteria: May 31, 2023
• First Posted (Actual): June 2, 2023

Study Record Updates

• Last Update Posted (Actual): December 30, 2025
• Last Update Submitted That Met QC Criteria: December 24, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: pressure; erectile dysfunction; hypesthesia; bicycling; saddle; transcutaneous blood gas monitoring; bike fit; biothesiometry
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Genital Diseases, Male; Male Urogenital Diseases; Sensation Disorders; Sexual Dysfunction, Physiological; Sexual Dysfunctions, Psychological; Somatosensory Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Erectile Dysfunction; Hypesthesia; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Respiratory System; Diagnostic Techniques, Cardiovascular; Physical Examination; Heart Function Tests; Respiratory Function Tests; Blood Chemical Analysis; Clinical Chemistry Tests; Blood Gas Analysis; Oximetry; Blood Gas Monitoring, Transcutaneous; Heart Rate Determination
• Other Study ID Numbers: CharlesUCR - EC-SADDLE; UK FTVS 002/2023 (Other Identifier: aculty of Physical Education and Sport, Charles University, Ethics Committee)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No