Accuracy of skindex machine and dunham testing

scotty2

Well-known member
Awards
1
  • Established
Had bf% measured today my a skindex caliper using the dunham scale. Wondering the acuracy of such tests. My bf was measured lower several weeks ago than it was today, I am somewaht leaner now than I was then.
 

YellowJacket

Banned
Awards
0
Sorry for missing this one.... I have an article that will interest you

EVALUATION OF POLICE HEART RATE IN STRESS TRAINING ENVIRONMENTS

By DeLois Ann Thomas, MBA and Les Knight, Ph.D., FACSM
(Article from Defensive Tactics Newsletter, October 2001, Volume XI, Number 1)

Introduction

The purpose of this study was to evaluate the heart rate of police in a stressful training environment. This study used ECG wireless heart rate monitors to obtain the data.

The study, in addition to providing data on heart rates of police in a stressful training environment, was to provide data to evaluate heart rate data used in the book Sharpening The Warrior's Edge The Psychology & Science of Training by Bruce Siddle. This book was published in 1995 and the data is used in the law enforcement community.

Review of Literature

The use of heart rate and stress data has been present in the literature for many years. The development of proven ECG-accurate wireless heart rate monitoring technology has produced many scientific studies and books on heart rate.

The first major book on heart rate and training was Training Lactate Pulse Rate in 1989 by Peter Janssen from Finland. Using ECG-accurate wireless heart rate monitoring technology he presented a wealth of data on the relationship between heart rate velocity of movement and the correlated levels of blood lactate. Dr. Janssen's book Lactate Threshold Training was published this year and presents some additional data.

Sally Edwards wrote The Heart Rate Monitor Book in 1992. This book indicated that heart rate monitors have brought high-tech biofeedback training into the reach of almost everyone. Note that this type of training was unheard of ten years ago. Sally Edwards's second book was Heart Zone Training in 1996 and introduced some new concepts on heart rate monitors.

The book Heart Monitor Training for the Complete Idiot by John Parker was available in 1993. This book was written primarily for runners but included how to use a heart rate monitor for general fitness.

The book Sharpening The Warrior's Edge The Psychology & Science of Training was written by Bruce Siddle in 1995. Siddle has written that the focal point of Sharpening the Warrior's Edge is controlling the heart rate. The book contains heart rate concepts on survival and combat performance.

Knight and Groppel wrote the book Basic Guide to Heart Rate Monitors in 1998 and is a book for the general public that explained the concepts of why and how to use a heart rate monitor. This book has been published in Arabic, Spanish and Chinese.

The book Precision Heart Rate Training was written by Ed Burke in 1998. This is a book with excellent exercise physiology concepts on heart rate.

The Book Heart Rate Based Exercises for Preventive Medicine was written by Knight in 1998 and provides guidelines for exercise programs with heart rate monitors. These exercises programs are designed for preventive medicine.

Some basic heart rate concepts are presented to help the reader understand the role of physiology with heart rate.

There is no normal resting heart rate. The heart rate does change as activities vary throughout the day. Most people's heart rate will fluctuate plus or minus a range of 40 bpm each day. Changes in postural position also affect heart rate.

One of the first things an individual needs to do when working with heart rate is to establish his or her maximum heart rate. There are errors inherent in estimating maximal heart rate with formulas. Individual values may vary plus or minus from this average value by approximately 15 beats per minute.

The Maximal Heart Rate is sport-specific. This means that an individual will have a different maximal heart rate for each sport. The heart rate number in running/walking would differ in bicycling or swimming. Part of this is explained by the position of the body during exercise as swimming is horizontal and running is vertical. Note that use of hand weights may raise the heart rate 10 to 15 beats per minute higher with running or cycling.

The variables that affect heart rate are altitude, clothing and air temperature. The heart rate will fluctuate if you are nervous or in an excited state, since adrenaline and other hormones will be released. The use of stimulants such as caffeine and ephedrine will affect heart rate response to activity. Remember that certain medications can also affect heart rate.

Heart rate zones are based on an individual's percentage of their Maximum Heart Rate. The term zone is used because heart rates should not be thought of as a specific number. Most books list 4 or 5 zones.

The Recovery Zone (50%) does not offer any training intensity, but plays a major role with exercising in the other 3 zones.

The Fat Burning Zone (50-65%) is the easiest intensity that you can work out and have improvement. Exercise in this zone is very relaxed and there is no sensation of being out of breath or pain from exercise.

Target Heart Rate Zone (65-85%) is the most popular zone for improving endurance and general fitness. The reason people can exercise for a long period of time is that there is not a build up of lactic acid in this zone.

Anaerobic Threshold Zone (85-100%) is when aerobic training becomes anaerobic training (lactate accumulation and oxygen debt). This zone produces pain, tired muscles, heavy breathing and fatigue. The body can only tolerate exercise in the zone for short periods of time.

Procedure

Heart rates, body fat calculations, waist measurements and Coopers 1-1/2 mile run test were administered to 12 police officers during August 17 and September 15, 2001. The sample group involved 8 males and 4 females with an age range of 22-45 years and an average age of 33.8 years. The time employed as a police officer was an average of 9.09 years with a range of 0.9-25.8 years. All tests were conducted in one controlled location.

The heart rates for each procedure were taken with ACUMEN TZ100 monitor. The ACUMEN heart rate monitor provided a heart rate measurement and not a pulse rate measurement. The resting heart rates were taken in (3) one-minute increments and averaged.

The body fat calculations were obtained with Skindex Caliper and all measurements were taken on the right side. The men's test sites were the chest, abdomen and thigh. The women's test sites were the triceps, suprailiac and thigh. The waist circumference measurement was taken with a cloth tape measure.

The type of stress training environment included officers having to simulate a 100-yard chase with a suspect. After catching the suspect the officer had to simulate a fight with suspect (baton strikes) for one minute until cover arrived.

Results

The male waist circumference had a range of 33-40 inches with average of 36 inches. The women had a range of 22-30 inches with average of 26 inches. There was one 36-year-old male officer with a waist measurement of 40 or above inches. Abdominal obesity is the issue with measurement of 40 inches or above in men. The women's measurement is 35 inches for abdominal obesity.

The percentage body fat included only 1 Poor classification. There were 2 officers with fair classification. Note that 3 officers were in excellent classification. Cooper classification was used with data.

The resting heart had a range of 38-71 bpm. The average resting heart rate was 58 bpm. The resting heart rates were all considered being within the normal range.

The formula for obtaining maximum heart rate was 220 - age. This maximum heart rate determination ranged from 175 to 195.

The maximum heart rate obtained at the finish of the Cooper's 1-1/2 mile run had 4 officers with higher than the predicated maximum heart rate values. There were 8 officers with lower than predicted maximum heart rate values. There were 7 officers in the Cooper 1-1/2 miles run test who were in the Excellent classification, 2 in Good classification, 1 in the Fair classification and 1 in the Very Poor classification.

The maximum heart rate recorded in the Law Enforcement Stress Training Environment ranged from 158 to 228 bpm. There were 3 officers with heart rates over 220 bpm. Also, there were a total of 9 officers with heart rates over 200 bpm. There were 11 officers with heart rates on the Stress Training Environment who was above their predicated maximum heart rate. Also, there were 9 officers with heart rates on the Stress Training Environment who were above the heart rate from the Cooper 1-1/2 mile run test.

The average heart rate recorded in the Stress Training Environment ranged from 119-188 bpm with the total average being 164 bpm. All of the individual average heart rates in the Stress Training Environment were below the Maximum Heart Rate recorded in the study.

The 5-minute Recovery Heart Rate after Stress Training Environment ranged from 85-116 bpm. All officers were under 120 bpm in the recovery time.

Summary

This study presents the law enforcement officer with data on the role of heart rate in a stressful training environment and defensive tactics. The stressful training environment produces a higher heart rate than the Cooper 1-1/2 mile run. The anaerobic situation and the use of the arms with the baton strikes can explain this higher heart rate.

The officer's heart rate will vary depending on the officer's duration and intensity during a stressful situation. Please note that officers in the same stress environment will produce different heart rates. These different heart rates also occur in defensive tactics training.

Heart rates used in law enforcement training need to be evaluated using heart rate zones. The heart rate will vary with individuals and different situations that can be constantly changing. Officers and instructors cannot use one heart rate number to determine the effects of stress in law enforcement work.

Defensive Tactics Instructors should be aware of the danger of training in the Anaerobic Threshold Zone. Also, Officers who are starting an exercise program should exercise in the Fat Burning Zone.
 

Similar threads


Top