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Prediction of one repetition maximum (1-RM) strength from a 4-6 RM and a 7-10 RM submaximal strength test in healthy young adult males

September 2002

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2002;5(3):54-59. The purpose of this investigation was to determine if 1-RM strength could be predicted from a 4-6 RM submaximal strength test with a greater accuracy than the commonly used 7-10 submaximal strength test. Thirty-four healthy males between the ages of 19 and 32 participated in this study. Subjects completed 1-RM, 4-6 RM, and 7-10 RM strength assessments in random order with a minimum of 48 hours between each strength assessment. During each session, subjects performed strength assessments for the bench press, incline press, triceps extension, biceps curl, and leg extension. Multiple regression analysis was used to produce equations for predicting 1-RM strength from 4 to 6 or 7 to 10 repetition maximum tests. The 4-6 RM prediction equations improved the predictive accuracy of 1-RM strength compared to the 7-10 RM prediction equations based on the adjusted R 2 and standard error of estimate. Since no injuries or symptoms of delayed onset of muscle soreness were reported during either the 7-10 RM or the 4-6 RM submaximal strength assessments, the results of this study indicate that when attempting to predict 1-RM strength in healthy, young, males, a 4-6 RM submaximal strength assessment appears to be the more accurate test.

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1 RM Strength Prediction 54

JEPonline

Journal of Exercise Physiologyonline

Official Journal of The American

Society of Exercise Physiologists (ASEP)

ISSN 1097-9751

An International Electronic Journal

Volume 5 Number 3 August 2002

Exercise Testing

PREDICTION OF ONE REPETITION MAXIMUM (1-RM) STRENGTH FROM A 4-6 RM

AND A 7-10 RM SUBMAXIMAL STRENGTH TEST IN HEALTHY YOUNG ADULT

MALES

PAULA DOHONEY, JOSEPH A. CHROMIAK, DEREK LEMIRE, BEN R. ABADIE AND CHRISTOPHER

KOVACS

Department of Health, Physical Education, Recreation, and Sport, Mississippi State University

ABSTRACT

PREDICTION OF ONE REPETITION MAXIMUM (1-RM) STRENGTH FROM A 4-6 RM AND A 7-10

RM SUBMAXIMAL STRENGTH TEST IN HEALTHY YOUNG ADULT MALES. Paula Dohoney, Joseph

A. Chromiak, Derek Lemire, Ben R. Abadie AND Christopher Kovacs. JEPonline. 2002;5(3):54-59. The

purpose of this investigation was to determine if 1-RM strength could be predicted from a 4-6 RM submaximal

strength test with a greater accuracy than the commonly used 7-10 submaximal strength test. Thirty-four healthy

males between the ages of 19 and 32 participated in this study. Subjects completed 1-RM, 4-6 RM, and 7-10 RM

strength assessments in random order with a minimum of 48 hours between each strength assessment. During

each session, subjects performed strength assessments for the bench press, incline press, triceps extension, biceps

curl, and leg extension. Multiple regression analysis was used to produce equations for predicting 1-RM strength

from 4 to 6 or 7 to 10 repetition maximum tests. The 4-6 RM prediction equations improved the predictive

accuracy of 1-RM strength compared to the 7-10 RM prediction equations based on the adjusted R2 and

standard error of estimate. Since no injuries or symptoms of delayed onset of muscle soreness were reported

during either the 7-10 RM or the 4-6 RM submaximal strength assessments, the results of this study indicate that

when attempting to predict 1-RM strength in healthy, young, males, a 4-6 RM submaximal strength assessment

appears to be the more accurate test.

Key Words: One repetition maximum (1-RM), Strength prediction, Submaximal strength.

INTRODUCTION

Weight training is recommended by allied health professionals to enhance physical fitness and overall health (1).

However, the methods for testing strength have become increasingly more sophisticated (2). Many studies have

been conducted to produce regression equations for predicting 1-RM strength, while other studies have been

undertaken to determine the accuracy of such equations. Several studies have extended research in this area by

further investigating such aspects as: (a) the predictive accuracy of regression equations with untrained and

1 RM Strength Prediction 55

technique-trained subjects (3,4,5,6), (b) differences in various groups of male subjects (7), (c) differences in male

and female performance (8,9,10), (d) the relationship between performances using different types of resistance

training equipment and types of strength exercises (11,12), and (e) the validity of repetitions -to-fatigue

equations for older adults (13,14,15).

In order to prescribe weight-training programs for a novice weight lifters, an exercise specialist typically

determines an individual's maximum lifting capacity. This weight is the maximal amount of weight that can be

lifted only one time, and is referred to as the one-repetition maximum (1-RM). Since muscular strength varies

depending on the muscle groups involved and the type of lift employed (e.g., bench press, biceps curl), maximal

lifting capacity must be assessed for each prescribed exercise. It has been suggested that novice lifters not

perform a 1-RM strength assessment, because lifting maximal weight by individuals not accustomed to weight

training may induce muscle soreness and increase the risk of more serious muscular injury (6).

In order to minimize the risk of strength assessment, regression equations have been developed to predict 1-RM

strength for larger muscle mass exercises for male subjects (16). Prediction of 1-RM strength allows an exercise

specialist to assess an individual's maximal lifting capacity without subjecting the novice lifter to the increased

risk associated with a 1-RM lift. The majority of studies that have reported prediction equations for 1-RM

strength used a 7-10 RM submaximal strength test (4,6,13). The purpose of this investigation was to determine

whether 1-RM strength could be predicted from 4-6 RM submaximal strength tests for both large and small

muscle mass exercises with greater accuracy than the commonly used 7-10 RM submaximal strength test.

METHODS

Subjects

Thirty-four healthy males between the ages of 19 and 32 years, who had not participated in strength training

within the last year, volunteered to participate in this study. Methods and procedures for the study were

approved by the institution and informed consent was obtained from participants. Subjects were instructed to

refrain from participating in strenuous activity for 24 hours prior to each testing session and to avoid alcohol,

caffeine, smoking and the consumption of large meals for at least three hours prior to testing.

Study Design

Body composition analysis included calculating percentage of body fat from the sum of three skinfold measures

(16). The sum of three skinfold measures was used to calculate body density, which was used to calculate

percent body fat using the Siri equation (17).

Subjects completed 1-RM, 4-6 RM, and 7-10 RM strength assessments in random order with a minimum of 48

hours between strength assessments. During each session, subjects performed strength assessments for the bench

press, incline press (28° incline), leg extension, biceps curl, and triceps extension in random order. While being

assessed for bench press and incline press strength, subjects lifted a free weight Olympic bar with weighted

plates. During the bench press and incline press assessments, subjects laid with their back flat on the bench and

their feet in full contact with the floor throughout the lift. Subjects grasped the bar with a thumb-lock grip at a

position slightly greater than shoulder width. Trained spotters assisted the subjects in lifting the bar from the

support rack, and the subject lowered the bar to the chest and returned the bar to full arm extension.

Strength of the leg extensors was assessed using a Cybex® leg extension machine. Subjects were seated with the

resistance bar positioned on a plane with the superior surface of the medial malleolus. Subjects lifted the weight

to near full extension of the knee. Biceps curl strength was assessed on a Paramount® preacher biceps curl

machine. Subjects sat in the preacher curl machine with the seat adjusted in order to position the upper arm to a

28° angle of elbow flexion. The triceps were flat on the curling pad and subjects' feet maintained full contact with

the floor throughout the lifts. Subjects lifted a 22.5 kg free weight bar with additional weight plates using a

1 RM Strength Prediction 56

supine grip at shoulder width. Spotters assisted the subjects in lifting the bar to the proper starting position.

Subjects curled the bar to 90° of elbow flexion. Triceps extension strength was assessed on a Body Master®

triceps extension press machine. Subjects stood against a backrest. A spotter moved the bar in order to position

the resistance bar at 90° of elbow flexion. Subjects used an overhand grip and attempted to extend their arms

until near full extension of the elbow was achieved. During all submaximal strength assessments, if subjects

could lift the weight greater than the desired number of repetitions indicated by the test protocol, subjects rested

for 5 to10 minutes and repeated the lift with additional weight.

Forty-eight hours following the completion of each strength test, subjects were asked the following questions:

(1) Did the strength assessment limit your ability to exercise within the last 48 hours?, and (2) Did you

experience noticeable muscle soreness within 48 hours of the strength assessment? These questions were asked in

order to determine the extent of any muscle injury and the onset of any delayed muscle soreness resulting from

the strength assessment.

Statistical Analyses

Stepwise multiple regression analysis was used to generate ten regression equations for predicting 1-RM strength

from the 4-6 RM and 7-10 RM submaximal strength tests. Four variables (weight lifted during the submaximal

strength test, the number of repetitions completed, the subject’s body weight, and the subject’s body

composition) were initially entered into the stepwise regression equation. The variables selected to predict 1-RM

for the exercises from both the 4-6 RM and 7-10 RM submaximal strength tests were the weight lifted during the

submaximal strength test and the number of repetitions completed. The degree of relationship between each

regression equation for predicting 1-RM strength from either 4-6 RM or 7-10 RM submaximal strength tests and

the actual 1-RM was determined using the correlation coefficient (r) and adjusted R2. The adjusted R2 value

equals the explained variance between the correlated values. The standard error of estimate (SEE), between the

measured and predicted 1-RM for each exercise, was used as a measurement of accuracy of the prediction

equation. The SEE was calculated as Sy/1-R2, where Sy is the standard deviation of the measured value.

RESULTS

The anthropometric characteristics of the subject population are presented in

Table 1. The regression equations for predicting 1-RM from 4-6 and 7-10-

RM tests are presented in Table 2. The corresponding correlation

coefficients (r) between predicted and measured 1-RM strength, the

adjusted R2, standard error of estimate (SEE), and SEE as a percentage of

the actual 1-RM are also reported in Table 2.

For each exercise, the prediction equation based on a 4-6 RM set was a better predictor of 1-RM strength than

the prediction equation based on a 7-10 RM set. For each exercise, the correlation between the predicted and

actual 1-RM, the standard error of estimate, and the adjusted R2 were improved when predicting 1-RM from a 4-

6 RM set compared with a 7-10 RM set.

No subjects reported that either the 4-6 RM submaximal strength assessment or the 7-10 RM submaximal

strength assessment limited their ability to exercise or caused noticeable muscle soreness. Six (17.5%) subjects

reported that the 1-RM strength assessment limited their ability to exercise. Twenty-one (61.2%) subjects

indicated that the 1-RM strength assessment created noticeable muscle soreness. If a subject reported that their

ability to exercise was limited, or they experienced noticeable muscle soreness, the next strength test was

postponed for an additional 48 hours. All of the subjects were able to participate in the strength assessment after

the 48 hour postponement.

Table 1. Anthropometric

measurements for the sample

population (n=34).

Variable Mean±±SD

Age (yr) 23.2±3.2

Height (cm) 181.5±5.7

Weight (kg) 84.1±11.5

Body Fat (%) 15.2

1.7

1 RM Strength Prediction 57

Table 2. Regression equations for predicting 1-RM from 4-6 and 7-10-RM tests.

Resistance Exercise Prediction Equations for

4-6 RM tests rAdjusted R2SEE SEE/1-RM (%)

Bench Press -24.62 + (1.12 x Wt) + (5.09 x reps) 0.97 0.93 11.0 5.6

Inclined Press -9.85 + (1.02 x Wt) + (5.70 x reps) 0.96 0.90 11.9 6.9

Triceps Extension 6.74 + (0.99 x Wt) + (1.61 x reps) 0.93 0.86 6.4 6.0

Biceps Curl 19.97 + (0.81 x Wt) + (2.31 x reps) 0.89 0.78 6.4 6.3

Leg Extension 82.07 + (0.76 x Wt) + (5.66 x reps) 0.82 0.66 26.3 8.4

Resistance Exercise Prediction Equations for

7-10 RM tests rAdjusted R2SEE SEE/1-RM (%)

Bench Press -1.89 + (1.16 x Wt) + (1.68 x reps) 0.95 0.91 13.5 6.9

Inclined Press 12.14 + (1.16 x Wt) + (0.10 x reps) 0.93 0.86 14.3 8.3

Triceps Extension -9.76 + (1.02 x Wt) + (3.56 x reps) 0.91 0.82 7.2 6.9

Biceps Curl 23.90 + (0.77 x Wt) + (2.16 x reps) 0.84 0.68 7.7 7.6

Leg Extension 95.00 + (0.65 x Wt) + (8.52 x reps) 0.76 0.56 30.1 9.7

DISCUSSION

Many strength prediction equations have been published including generalized equations and exercise specific

equations (4,7,12). This paper presents strength prediction equations for five strength training exercises with two

different repetition ranges.

For each strength-training exercise, the prediction equation based on a 4-6 RM set was a better predictor of 1-

RM strength than the prediction equation based on a 7-10 RM set. The results of this study suggest that the

predictive accuracy of the prediction equations is greatest for the upper body exercises, such as the bench press

and incline press, compared to lower body exercises, such as the leg extension. Because this study utilized only

one lower body test, this outcome may not be true of all lower body exercises. The correlation coefficients were

lowest and standard error of estimate greatest for the leg extension strength prediction equations compared with

the other four prediction equations in both the 4-6 RM and 7-10 RM sets.

These prediction equations were developed for use on non-strength trained individuals. Studies have revealed

that prediction equations are not applicable to strength-trained individuals (6,18) and that proper lifting technique

does not necessarily alter maximal and submaximal lifting performance (4). Prediction equations are specific to

the training status of the individuals and resistance training has been found to alter the relationship between

maximal and submaximal strength (6). However, prediction equations will tend to be most accurate for those

individuals who are closest to the mean for the group. For individuals who are capable of lifting heavy weights,

the prediction equations will tend to under-predict their 1-RM strength. Typically, a strength-trained individual

can complete more repetitions with any given percentage of their 1-RM than an individual who is not strength-

trained (19).

Conclusion

This study sought to determine whether 1-RM strength could be predicted from 4-6 RM submaximal strength

tests for large and small muscle mass exercises with greater accuracy than the commonly used 7-10 RM

1 RM Strength Prediction 58

submaximal strength test. The 4-6 RM submaximal strength test improved the predictive accuracy of 1-RM

strength compared to the 7-10 RM submaximal strength assessment in each of the five assessments of 1-RM

strength. Since no injuries or symptoms of delayed onset of muscle soreness were reported during either the 7-

10 RM or the 4-6 RM submaximal strength assessment, the results of this study indicate that when attempting to

predict 1-RM strength in untrained male subjects with similar characteristics, a 4-6 RM submaximal strength

assessment appears to be a more valid and effective test.

Further research could determine the validity of such prediction equations for male subjects with different

characteristic means (age, height, weight, % body fat), female subjects, adolescents, the elderly, and other subject

groups. The use of such prediction equations to determine 1-RM has practical value for allied health

professionals in assessing and prescribing strength training programs.

Address for correspondence: Paula Dohoney, Department of Health, Physical Education, Recreation, and

Sport, Mississippi State University, P.O. Box 6186, Mississippi State, MS 39762-6186; Phone: (662) 325-7234;

FAX: (662) 325-4525; Email: pdohoney@colled.msstate.edu

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Chapter

Feb 2025

Creatine (Cr) supplementation has been widely used by athletes and resistance exercise practitioners to improve physical performance and muscle recovery. Despite this, not all of its effects are fully understood, especially in the context of the load protective effect (WPE). This study investigated whether Cr supplementation can enhance WPE and reduce markers of muscle damage in 20 healthy men who had been weight training for more than six months (age: 26 ± 7 years; body mass: 81.3 ± 9.2 kg; height: 177 ± 0.07 cm). Participants were randomly divided into two groups: creatine supplementation (CRE) and placebo (PLA). The CRE group received 20 g of creatine monohydrate per day (4 doses of 5 g), while the PLA group received maltodextrin at the same dosage. The experimental protocol was conducted over 25 days and included strength testing (1RM in the Scott bench biceps curl exercise), blood collection for creatine kinase (CK) analysis and evaluation of delayed onset muscle soreness (DOMS). The results showed that Cr supplementation significantly reduced the perception of pain after the first and second exercise sessions, in addition to promoting a more attenuated response in CK levels compared to the PLA group. The CRE group also showed a significant increase in total body mass (TBM), which was not observed in the PLA group. These findings indicate that Cr supplementation can enhance EPC, reducing exercise-induced muscle damage and aiding in the continuity of strength training programs. Future studies are needed to investigate the mechanisms associated with these effects.

SUPLEMENTAÇÃO DE CREATINA POTENCIALIZA O EFEITO PROTETOR DA CARGA E REDUZ DANOS MUSCULARES EM PRATICANTES DE TREINAMENTO DE FORÇA

Article

Full-text available

Feb 2025

A suplementação de creatina (Cr) tem sido amplamente utilizada por atletas e praticantes de exercícios resistidos para melhora no desempenho físico e recuperação muscular. Apesar disso, nem todos os seus efeitos são completamente conhecidos, especialmente no contexto do efeito protetor da carga (EPC). Este estudo investigou se a suplementação de Cr pode potencializar o EPC e reduzir marcadores de dano muscular em 20 homens saudáveis, praticantes de musculação há mais de seis meses (idade: 26 ± 7 anos; massa corporal: 81,3 ± 9,2 kg; estatura: 177 ± 0,07 cm). Os participantes foram divididos aleatoriamente em dois grupos: suplementação de creatina (CRE) e placebo (PLA). O grupo CRE recebeu 20 g de creatina monoidratada por dia (4 doses de 5 g), enquanto o grupo PLA recebeu maltodextrina na mesma dosagem. O protocolo experimental foi conduzido ao longo de 25 dias e incluiu testes de força (1RM no exercício rosca bíceps no banco Scott), coleta sanguínea para análise da creatina quinase (CK) e avaliação da percepção de dor muscular tardia (DMT). Os resultados mostraram que a suplementação de Cr reduziu significativamente a percepção de dor após a primeira e a segunda sessões de exercício, além de promover uma resposta mais atenuada dos níveis de CK em comparação ao grupo PLA. O grupo CRE também apresentou um aumento significativo na massa corporal total (MCT), o que não foi observado no grupo PLA. Esses achados indicam que a suplementação de Cr pode potencializar o EPC, reduzindo o dano muscular induzido pelo exercício e auxiliando na continuidade de programas de treinamento de força. Estudos futuros são necessários para investigar os mecanismos associados a esses efeitos.

Impact of Different Low-Volume Concurrent Training Regimens on Cardiometabolic Health, Inflammation, and Fitness in Obese Metabolic Syndrome Patients

Article

Full-text available

Jan 2025

Background/Objectives: Evidence supports the benefits of concurrent training (CT), which combines endurance and resistance exercises, for enhancing health and physical fitness. Recently, low-volume, time-efficient exercise approaches such as low-volume high-intensity interval training (LOW-HIIT), whole-body electromyostimulation (WB-EMS), and single-set resistance training (1-RT) have gained popularity for their feasibility and efficacy in improving various health outcomes. This study investigated the effects of low-volume CT, focusing on (1) whether exercise order affects cardiometabolic health, inflammation, and fitness adaptations and (2) which combination, LOW-HIIT plus WB-EMS or LOW-HIIT plus 1-RT, yields better results. Methods: Ninety-three obese metabolic syndrome (MetS) patients undergoing caloric restriction were randomly assigned to four groups performing the different low-volume CT protocols over 12 weeks. Outcomes included cardiometabolic, inflammatory, and fitness parameters. Results: In both combinations, no significant differences were found regarding exercise order. However, the pooled LOW-HIIT and 1-RT group achieved superior improvements in blood pressure, blood lipids, inflammation markers (CRP, hsCRP), the MetS severity score, and overall fitness compared to the LOW-HIIT and WB-EMS combination. Compared to previous studies using these modalities individually, LOW-HIIT plus 1-RT appeared to further reduce inflammation, whereas LOW-HIIT combined with WB-EMS was less effective for cardiometabolic health, potentially due to interference effects between modalities. Conclusions: While LOW-HIIT plus WB-EMS appears to be a viable option for individuals unable to perform traditional resistance training, the findings suggest prioritizing LOW-HIIT plus 1-RT to maximize health outcomes. These findings highlight the importance of tailored exercise prescriptions and the need for further research into optimizing CT protocols for diverse populations.

Protein Supplementation Increases Adaptations to Low-Volume, Intra-Session Concurrent Training in Untrained Healthy Adults: A Double-Blind, Placebo-Controlled, Randomized Trial

Article

Full-text available

Aug 2024

Combined endurance and resistance training, also known as “concurrent training”, is a common practice in exercise routines. While concurrent training offers the benefit of targeting both cardiovascular and muscular fitness, it imposes greater physiological demands on the body compared to performing each modality in isolation. Increased protein consumption has been suggested to support adaptations to concurrent training. However, the impact of protein supplementation on responses to low-volume concurrent training is still unclear. Forty-four untrained, healthy individuals (27 ± 6 years) performed two sessions/week of low-volume high-intensity interval training on cycle ergometers followed by five machine-based resistance training exercises for 8 weeks. Volunteers randomly received (double-blinded) 40 g of whey-based protein (PRO group) or an isocaloric placebo (maltodextrin, PLA group) after each session. Maximal oxygen consumption (VO2max) and overall fitness scores (computed from volunteers’ VO2max and one-repetition maximum scores, 1-RM) significantly increased in both groups. The PRO group showed significantly improved 1-RM in all major muscle groups, while the PLA group only improved 1-RM in chest and upper back muscles. Improvements in 1-RM in leg muscles were significantly greater in the PRO group versus the PLA group. In conclusion, our results indicate that adaptations to low-volume concurrent training, particularly leg muscle strength, can be improved with targeted post-exercise protein supplementation in untrained healthy individuals.

Strength Testing—Predicting a One-Rep Max from Reps-to-Fatigue

Article

Full-text available

Jan 1993

Matthew Brzycki

VALIDITY OF PREDICTING 1RM AND %1RM IN WEIGHTTRAINED AND UNTRAINED MALES.

Article

May 1995

Does a Regression Equation to Predict Maximal Strength in Untrained Lifters Remain Valid When the Subjects Are Technique Trained?

Article

Aug 1999

This study was implemented to determine if predicting 1 repetition maximum (1RM) bench press strength in untrained lifters from a 7-10RM strength test remains valid when subjects practiced the proper bench press technique. Thirty men 18-26 years of age participated in 2 testing sessions to assess 1RM and 7-10RM bench press strength. The sessions were separated by a minimum of 48 hours. Regression analysis indicated the following equation to predict 1RM strength from weight lifted during the 7-10RM strength test: 1RM = 8.841 + (1.1828*7-10RM). Analysis of predictive accuracy of the regression equation indicated correlation of r = 0.969 (SEE = 4.2 kg or 5.56% of the measured [M] 1RM). Subjects were randomly assigned to an experimental group or a control group. The experimental group practiced proper lifting technique during 4 training sessions during a 2-week period. The control group did not lift weights during this period. Following training, all subjects were reassessed for 1RM and 7-10RM bench press strength. Using the regression equation developed before training, the experimental group demonstrated a correlation of r = 0.983 (SEE = 3.1 kg or 4.2% of M 1RM). The control group demonstrated a correlation of r = 0.989 (SEE = 2.5 kg or 8.8% of the M 1RM). An independent t-test comparing the differences between posttraining bench press scores indicated no significant difference in bench press lifting ability between the experimental group (82.96 kg) following technique training and the control group (75.69 kg). Although the experimental group demonstrated a trend for increased lifting ability following instruction, results suggest that lifting technique does not affect the accuracy of the regression equation to predict 1RM strength.

Prediction of bench press lifting ability from submaximal repetitions before and after training

Article

Jun 1992
Sports Med Train Rehabil

The purpose of this study was to determine the accuracy of predicting maximal bench press lifting strength from submaximal bench press repetitions before and after a training program. College students (70 men; 101 women) were tested to determine their one repetition maximum (1‐RM) bench press lifting strength before and after 14 weeks of training. Several days after an initial maximum lift determination, each subject was randomly assigned a submaximal load corresponding to 55 to 95% of the 1‐RM and required to perform as many bench press repetitions as possible in 1 minute. The same percent 1‐RM was used following training, as was used before training, to test lifting capacity at a defined percent of the initial 1‐RM for a given individual. Men had a significantly greater 1‐RM bench press strength and absolute integrated submaximal weightlifting ability than women but were not significantly different in percent 1‐RM and repetitions. The exponential relationship between percent 1‐RM and repetitions before and after training did not differ significantly between men and women. Using this relationship, 1‐RM bench press lifting strength could be estimated with a validity coefficient of r >0.90 and a standard error of 2.9 to 3.5 kg for women and 5.7 to 6.6 kg for men regardless of the training state of each group. It was concluded that the number of repetitions completed in 1 minute of lifting a submaximal load can provide an accurate estimate of maximal bench press lifting strength regardless of training status.

The Accuracy of Prediction Equations for Estimating 1-RM Performance in the Bench Press, Squat, and Deadlift

Article

Nov 1997

This study was done to determine the accuracy of 7 equations for predicting a 1-RM from repetitions to fatigue for the bench press, squat, and deadlift. Subjects, 67 untrained college students (40 M, 27 F) who were enrolled in weight training classes, participated in four 45-min practice sessions to learn proper lifting technique and determine the amount of weight to lift for the 1-RM test. All correlation coefficients between predicted and achieved 1-RM lifts were high (r > 0.95). For the bench press, however, the average differences between achieved and predicted weights were significantly different from zero in all but 2 equations. For the squat, the average difference was significantly different from zero in all but 1 equation. All equations significantly underestimated the deadlift despite high correlations. (C) 1997 National Strength and Conditioning Association

Relative Muscular Endurance Performance as a Predictor of Bench Press Strength in College Men and Women

Article

Nov 1992

The purpose of this study was to determine the accuracy of using relative muscular endurance performance to estimate 1 RM bench press strength. College students (184 men and 251 women) were tested for 1 RM strength following 14 weeks of resistance training. Each subject was then randomly assigned a relative endurance load (rep weight) corresponding to 55-95 percent of the 1 RM and required to perform as many bench press repetitions (reps) as possible in one minute. Men had significantly greater 1 RM strength, rep weight, percent 1 RM, and reps than women. Since the regression of percent 1 RM on reps was not significantly different between the men and women, the data were combined to produce the following exponential equation: percent 1 RM = 52.2 + 41.9e -0.055 reps (r = 0.80, p < 0.001). Bench press strength could be estimated from the equation 1 RM = rep weight/predicted percent 1 RM/l00 with an accuracy of r = 0.98 and a standard error of estimate of +/- 4.8 kg. Applications of these equations to a comparable cross-validation group (70 men and 101 women) indicated acceptable validity (r = 0.98, p < 0.001) with an error of only +/- 5.4 kg. Applying the same equations to high school male athletes (n = 25), high school male nonathletes (n = 74) and college football players (n = 45) also produced good cross validation (r > 0.95, p < 0.001) with relatively small standard errors (+/- 3.1 to +/- 5.6 kg). It appears that relative muscular endurance performance can be used to accurately estimate 1 RM bench press strength in a wide variety of individuals. (C) 1992 National Strength and Conditioning Association

Validity of 1RM Prediction Equations for Older Adults

Article

Aug 1999

This study examined the validity of 6 1-repetition maximum (1RM) repetitions-to-fatigue prediction equations on 11 machine lifts for 51 older adults (70.7 +/- 6.1 years). In the first session, subjects selected a weight that they could lift for 7-10 repetitions on each machine exercise, and a 1RM was predicted using 6 different equations. In session 2, subjects completed an actual 1RM by selecting the maximum load that they could safely lift once (1-3 reps). Correlations between the actual and the 6 predicted 1RM scores demonstrated a moderate to strong relationship for all exercises (upper extremity: r = 0.77-0.90; lower extremity: r = 0.60-0.80). The average predicted 1RM value was lower than the actual 1RM for all exercises and all prediction equations (p <= 0.001). The use of a prediction equation for older adults appears to be a valid measure of 1RM within a range of 1-10 kg, depending on the machine lift. In all cases, the prediction equation underestimated the actual 1RM. (C) 1999 National Strength and Conditioning Association

Relationship between Repetitions and Selected percentages of One Repetition Maximum: A Comparison between Untrained and Trained Males and Females

Article

May 1990

Ninety-one subjects were tested to determine the number of repetitions they could perform at 40, 60, and 80 percent of one repetition maximum (percent 1 RM) for each of seven specified weight training lifts. Thirty-eight subjects from a previous study (18) were also included in the data analysis. The subjects represented four categories: untrained males (n = 38), untrained females (n = 40), trained males (n = 25) and trained females (n = 26). The results indicated that there was a significant difference (p < 0.05) in the number of repetitions that males and females can perform at the selected percent 1 RM among the seven weight training lifts, as well as in the number of repetitions performed at these percentages across lifts. When comparing untrained and trained males, a significant difference (p < 0.05) was found in the number of repetitions performed at all selected percent 1 RM for the arm curl, knee extension and sit-ups. Significant differences (p < 0.05) were also found at 60 percent 1 RM for the leg curl and at 60 and 80 percent 1 RM for the lateral pulldown. No significant differences (p > 0.05) were found for any percent 1 RM for the bench press and the leg press. When comparing untrained and trained females, a significant difference in performance (p < 0.05) was found among all seven lifts at 40 percent 1 RM. Significant differences (p < 0.05) were found at 60 percent 1 RM for the knee extension, bench press, sit-ups, leg curl and leg press; and at 80 percent 1 RM for the bench press, sit-ups and leg press. The findings of this study indicate that a given percent of 1 RM will not always elicit the same number of repetitions when performing dafferent lifts. (C) 1990 National Strength and Conditioning Association

Does A Regression Equation to Predict Maximal Strength in Novice Lifters, Remain Valid When the Subjects Are Technique Trained? 48

Article

May 1997

A Field Test for Predicting Maximum Bench Press Lift of College Women

Article

May 1992

The purpose of this study was to determine the relationship between absolute muscular endurance and the maximum weight that could be lifted in a bench-press exercise. Subjects were 84 untrained, healthy women ranging from 18 to 25 years of age. Within 72 hours, each subject performed a maximal (1 RM) bench press with free weights, the YMCA bench press test using 15.9 kg (35 pounds) and a modified YMCA bench press test using 20.4 kg (45 pounds). Care was taken to maintain proper form and technique for each exercise. Results of a multiple regression analysis revealed that bench press absolute endurance, plus body weight, was more effective for predicting bench press 1 RM (variance accounted for 66 percent; standard error of estimate = 3.27 kg, using 15.9 kg; and 72 percent of the variance accounted for SEE = 2.95 kg, using 20.4 kg) than absolute muscular endurance alone (62 percent and 67 percent; SEE = 3.34 and 3.14 kg for 15.9 and 20.4 kgs, respectively). Cross-validation (n = 19) of the prediction equations using the bench press absolute muscular endurance tests of 15.9 and 20.4 kg accounted for 67 and 66 percent of the variance between the measured and predicted bench press 1 RM (SEE = 2.91 and 2.99 kg). The results of this study suggest that bench press absolute muscular endurance, combined with body weight, can be used to predict maximal bench press lift in untrained to moderately weight-trained women, and may be used as a safe, time-efficient alternative to the one-repetition maximum bench press test in the assessment of upper body strength. (C) 1992 National Strength and Conditioning Association

Prediction of one repetition maximum (1-RM) strength from a 4-6 RM and a 7-10 RM submaximal strength test in healthy young adult males

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