James L. Nuzzo

• PhD
• Writer at The Nuzzo Letter

Today, the historical representation of women as participants in exercise science research is frequently discussed. Often omitted from these discussions is women’s participation in early research in fields that are historically linked to exercise science (e.g., physical education, physical therapy). Because much interest in women’s health was expre...

On average, adult men are physically stronger than adult women. The magnitude of this difference depends on the muscle tested, with larger sex differences observed in upper‐ than lower‐limb muscles. Whether body region‐specific sex differences in strength exist in children is unclear. The purpose of the current meta‐analysis was to determine whethe...

In 1985, Thomas and French published results of a meta‐analysis that examined sex differences in grip strength in children 5 years of age and older. Their analysis included results from only four studies, and no update has been published. The purpose of the current study was to use meta‐analysis to examine sex differences in grip strength from birt...

The history of exercise science research has undergone relatively little examination, and exercise science students receive little education about the field's history. Photographs are tools that lecturers and writers can use to educate audiences about history. Yet, no resource exists that tells educators where they can find photographs of individua...

The number of degrees conferred by postsecondary institutions in an academic field reflects institutional priorities, public interest in a domain of human knowledge, and overall societal and economic demand for certain skills and abilities. Public postsecon-dary institutions, which are obligated to serve the public interest, and professional organi...

During sustained or repeated maximal voluntary efforts, muscle fatigue (acute strength loss) is not linear. After a large initial decrease, muscle strength plateaus at approximately 40% of baseline. This plateau, which likely reflects muscle strength preservation, has been observed in sustained maximal isometric and repeated maximal isokinetic cont...

Many individuals do not participate in resistance exercise, with perceived lack of time being a key barrier. Minimal dose strategies, which generally reduce weekly exercise volumes to less than recommended guidelines, might improve muscle strength with minimal time investment. However, minimal dose strategies and their effects on muscle strength ar...

An eccentric muscle action (or contraction) is defined as active muscle lengthening against resistance, which occurs when the force generated by the muscle is smaller than the resistance placed upon it. Eccentric resistance exercise, which involves multiple sessions of repeated eccentric muscle actions, improves muscle strength and other health out...

The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) [REPS ~ %1RM relationship] is foundational knowledge in resistance exercise programming. The current REPS ~ %1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-indivi...

The actual capacity to perform tasks, and actual fatigue, are concepts that have been thought of as inherently linked. These considerations also extend to their phenomenology, meaning the perception(s) of capacity or fatigue. The phenomenology of capacity or fatigue thus may be capturing the same underlying latent construct. Further, it is speculat...

Biopsies have been acquired from living men and women to determine proportions of Type I (slow‐twitch) and II (fast‐twitch) skeletal muscle fibers since the 1970s. Sex differences have been assumed but the literature has not been submitted to meta‐analysis. Here, the aim was to generate effect sizes of sex differences in muscle fiber cross‐sectiona...

Since the 1970s, researchers have studied a potential difference in muscle fatigue (acute strength loss) between maximal eccentric (ECCmax) and concentric (CONmax) resistance exercise. However, a clear answer to whether such a difference exists has not been established. Therefore, the aim of our paper was to overview methods and results of studies...

Key points Editorials are typically brief comments by a journal's chief editor or associate editors on journal news, study findings, or trends in science or practice. Anonymous editorials, which account for 1%–3% of editorials indexed in PubMed, are those in which the author's name is absent or replaced by the journal's name. Chief editors cannot b...

Unequal proportions of male and female participants in exercise research might be attributed, in part, to differences in interest and willingness to participate. We tested if men and women are equally interested and willing to undergo exercise research procedures and if they consider different factors when deciding to participate. Two samples compl...

The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) (REPS~%1RM relationship) is foundational knowledge in resistance exercise programming. The current REPS~%1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-individual...

For decades, researchers have observed that eccentric (ECC) muscle strength is greater than concentric (CON) muscle strength. However, knowledge of the ECC:CON strength ratio is incomplete and might inform resistance exercise prescriptions. Our purposes were to determine the magnitude of the ECC:CON ratio of human skeletal muscle in vivo and explor...

Eccentric resistance exercise emphasizes active muscle lengthening against resistance. In the past 15 years, researchers and practitioners have expressed considerable interest in accentuated eccentric (i.e., eccentric overload) and eccentric-only resistance exercise as strategies for enhancing performance and preventing and rehabilitating injuries....

Cutting of boys’ and girls’ genitalia is a debated human rights topic. Here, the first aim was to summarise why parents choose to have these procedures performed on their children. Results from 22 survey studies on ‘male circumcision’ and 27 studies on ‘female genital mutilation’ revealed that non-medical reasons, such as tradition, are prominent i...

Letters to the editor are an important part of democratic societies. In academic journals, letters serve as a form of post-publication review and thus permit the continued discussion and debate of scientific ideas. However, letters and their importance are rarely taught to university students. Therefore, the aim of the current paper is to propose a...

Purpose Connected adaptive resistance exercise (CARE) machines are new equipment purported to adjust resistances within and between repetitions to make eccentric (ECC) overload and drop sets more feasible. Here, we examined muscle strength, endurance, electromyographic activity (EMG), and perceptions of fatigue during unilateral bicep curl exercise...

Connected adaptive resistance exercise (CARE) machines are new technology purported to adjust resistance exercise loads in response to muscle fatigue. The present study examined muscle fatigue (strength loss, fatigue perceptions) during maximal eccentric-only (ECCmax -only), concentric-only (CONmax -only), and coupled ECC-CON (ECCmax -CONmax ) bice...

The actual capacity to perform tasks, and actual fatigue, are concepts that have been thought of as inherently linked. These considerations also extend to their phenomenology, meaning the perception(s) of capacity or fatigue. The phenomenology of capacity or fatigue thus may be capturing the same underlying latent construct. Further, it is speculat...

Nuzzo, JL. Narrative review of sex differences in muscle strength, endurance, activation, size, fiber type, and strength training participation rates, preferences, motivations, injuries, and neuromuscular adaptations. J Strength Cond Res 37(2): 494-536, 2023-Biological sex and its relation with exercise participation and sports performance continue...

Nuzzo, JL. Content analysis of patent applications for strength training equipment filed in the United States before 1980. J Strength Cond Res XX(X): 000-000, 2021-Strength training history is an emerging academic area. The aim of the current study was to describe quantitively the history of inventions for strength training equipment. Content analy...

Letters to the editor are often critiques of published research papers. Journal editors acknowledge the importance of letters in post-publication review, yet the themes of letters remain unclear. Incidentally, letters can also be used to examine “authorship inflation” in academic publishing, as confounders (e.g., research complexity) are naturally...

Nuzzo, JL. Inconsistent use of resistance exercise names in research articles: a brief note. J Strength Cond Res XX(X): 000-000, 2021-Academic fields require standard nomenclature to communicate concepts effectively. Previous research has documented resistance training exercises are named inconsistently. This inconsistent use has been observed amon...

Nuzzo, JL. History of strength training research in man: an inventory and quantitative overview of studies published in English between 1894 and 1979. J Strength Cond Res XX(X): 000-000, 2020-Limited scholarship exists on the history of strength training research. The current review advances existing qualitative and biographical work by inventoryin...

For a fatigued hand muscle, group III/IV afferent firing maintains intracortical facilitation (ICF) without influencing corticospinal excitability. Exercise of larger muscles produces greater afferent firing. Thus, this study investigated if fatigue-related firing of group III/IV afferents from a large muscle group (quadriceps) modulates intracorti...

In 1973, Harriet Williams published in Quest on volunteer bias (self-selection bias) in kinesiology research. Williams’ evidence-based commentary included a discussion on sex differences in volunteerism. More recently, some exercise and sports scientists (ESS) have suggested investigator bias explains the lower proportion of female than male partic...

We examined if transcranial magnetic stimulation (TMS) is a valid tool for assessment of voluntary activation of the knee extensors in healthy individuals. Maximal M-waves (M max ) of vastus lateralis (VL) were evoked with electrical stimulation of femoral nerve (FNS); M max of medial hamstrings (HS) was evoked with electrical stimulation of sciati...

Males fare worse than females on many health outcomes, but more attention, particularly at a national level, is given to women’s issues. This apparent paradox might be explained by gamma bias or a similar gender bias construct. Such potential biases require exploration. The purpose of the current paper is to present six streams of evidence that ill...

Key points Letters to the editor are important to science because they are a form of post‐publication review. Examination of 3,203 letters published in exercise science and physical therapy journals revealed letters are indexed inconsistently. Issues exist with letter titles, letter authorship, and letter digital object identifiers (DOIs) and PubMe...

Background: Previous data from the United States Centers for Disease Control and Prevention indicate men are more likely than women to participate in muscle-strengthening activities (e.g., resistance training). However, a recent review by Rhodes et al. concluded there is no reliable sex difference in participation. The purpose of the current paper...

An influential journal in the history of kinesiology is Research Quarterly for Exercise and Sport (RQES). In 2005, RQES published a historical review in which the authors claimed the first training study in RQES to focus on women was by Wallace in 1975. In the current paper, the author corrects this historical inaccuracy. The electronic archives of...

Flexibility refers to the intrinsic properties of body tissues that determine maximal joint range of motion without causing injury. For many years, flexibility has been classified by the American College of Sports Medicine as a major component of physical fitness. The notion flexibility is important for fitness has also led to the idea static stret...

The “feet on the floor” guideline for the bench press is a historical byproduct of old bench designs. The “psoas-relaxed position,” where the hips and knees are flexed and the feet rest on adjustable plates at the end of the bench, should be considered to replace existing guidelines. The psoas-relaxed position accommodates lifters of all body heigh...

Letters to editors of journals are a hallmark of scientific debate and communication. Incidentally, letters also serve as a relatively unconfounded model to test for a potential sex difference in scientific engagement because opportunity to write letters is equal. When studied in exercise science and physical therapy journals, the model is strength...

Anecdotally, exercise science has experienced substantial growth in the past 20 years. Limited descriptions of this growth exist. In the current report, the author describes the number of exercise science bachelor’s, master’s, and doctoral degrees awarded in the United States from 2002–03 to 2016–17. Data were retrieved from the National Center for...

A health paradox exists in the United States. Men have worse health outcomes than women, but national offices exist for promoting women's but not men's health. Two factors that might contribute to this paradox are: underappreciation for the number of health issues that affect men more than women and unawareness that men’s health receives less atten...

Resistance training increases muscle size (i.e., causes hypertrophy) and muscle strength, particularly in untrained individuals. Hypertrophy is widely believed to be one of the mechanisms (i.e., a mediator) by which resistance training increases strength. However, some researchers have questioned whether training-induced hypertrophy causes increase...

Rates of participation in physical activity are often not the same between groups in a given demographic category. These differences have been termed ‘inequities,’ and major health organizations are advocating large-scale initiatives to create ‘equity’ in physical activity. The aim of this paper is to explain why equity in physical activity is a mi...

New findings: What is the central question of this study? Corticospinal excitability to biceps brachii is known to modulate according to upper-limb posture. Here, cervicomedullary stimulation was used to investigate potential spinal contributions to elbow angle-dependent changes in corticospinal excitability at rest. What is the main finding and i...

Objectives The hypoalgesic effects of exercise are well described, but there are conflicting findings for different modalities of pain; in particular for mechanical vs thermal noxious stimuli, which are the most commonly used in studies of exercise-induced hypoalgesia. The aims of this study were 1) to investigate the effect of aerobic exercise on...

Muscle strength - the maximal force generating capacity of a muscle or group of muscles - is regularly assessed in physiological experiments and clinical trials. An understanding of the expected variation in strength and the factors that contribute to this variation is important when designing experiments, describing methodologies, interpreting res...

Cervicomedullary motor evoked potentials (CMEPs) in relaxed biceps brachii have been reported to facilitate after acute isometric exercise of the elbow flexors. This facilitation, which reflects either enhanced corticospinal transmission or increased motoneurone excitability, has only been documented in the limb posture used during exercise. In Exp...

Purpose: Neural adaptations to strength training have long been recognized, but knowledge of mechanisms remains incomplete. Using novel techniques and a design which limited experimental bias, this study examined if 4 weeks of strength training alters voluntary activation and corticospinal transmission. Methods: Twenty-one subjects were randomiz...

Introduction: The maximal compound muscle action potential (Mmax ) of biceps brachii is altered by 1 session of strength training. We examined whether the number of training sets in a session plays a role in this effect. Methods: Ten subjects completed 1 session of isometric strength training of the elbow flexors (2 sets, 75% maximal force with...

Biceps brachii motor evoked potentials (MEP) from cortical stimulation are influenced by arm posture. We used subcortical stimulation of corticospinal axons to determine whether this postural effect is spinal in origin. While seated at rest, 12 subjects assumed several static arm postures, which varied in upper-arm (shoulder flexed, shoulder abduct...

Acute strength training of forearm muscles increases resting twitch forces from motor cortex stimulation. It is unclear if such effects are spinal in origin and if they also occur with training of larger muscles. Using subcortical stimulation of corticospinal axons, the current study examined if one session of strength training of the elbow flexor...

Limited research exists on the language associated with resistance training. The purpose of this study was to identify the ways in which resistance training exercises are named. Names of 57 exercises were obtained from the National Strength and Conditioning Association's Exercise Technique Manual for Resistance Training. The analysis consisted of c...

The primary purpose of this study was to identify the most appropriate method for normalizing physical performance measures to body mass in American football players. Data were obtained from the population of players (n = 4,603) that completed the vertical jump, broad jump, 40-yd sprint, 20-yd shuttle, 3-cone drill, and bench press at the National...

AS THE STRENGTH AND CONDITIONING FIELD CONTINUES TO GROW, DISCUSSIONS WITHIN THE FIELD SHOULD ENCOMPASS TOPICS OUTSIDE OF THE HUMAN MOVEMENT SCIENCES, SUCH AS BUSINESS. IN THIS ARTICLE, IT IS PROPOSED THAT THE FIELD OF STRENGTH AND CONDITIONING NOW CONSISTS OF 2 GENERALLY DIFFERENT TYPES OF PRACTICES: COMMERCIAL AND NONCOMMERCIAL. DEFINITIONS AND C...

Firefighters have a high incidence of low back pain and injury. To describe lumbar multifidus and abdominal muscle size characteristics in firefighters and to compare these characteristics to normative reference ranges. In career firefighters without current low back pain (62 males, 7 females), ultrasonography was used to assess: L4 and L5 lumbar m...

Firefighting is a dangerous occupation with a high incidence of low back pain and injury. Abnormal back muscle function and morphology has been linked to low back pain and poor physical performance. The effect of exercise training on back muscle size and symmetry has not been investigated in firefighters. The purpose of this study was to assess the...

Nuzzo, JL and McBride, JM. The effect of loading and unloading on muscle activity during the jump squat. J Strength Cond Res 27(7): 1758-1764, 2013-The purpose of this study was to explore the effect of loading and unloading on lower-body muscle activity during the jump squat (JS). Thirteen strength-power trained male subjects completed JS with loa...

The purpose of this preliminary study was to assess lumbar multifidus, erector spinae, and quadratus lumborum muscle activity during lifts as measured by changes in transverse relaxation time (T2) from magnetic resonance imaging (MRI). Thirteen healthy adults performed dynamic squat, stoop, and asymmetric stoop lifts at a standard load, with each l...

A consensus has not been reached among strength and conditioning specialists regarding what physical fitness exercises are most effective to stimulate activity of the core muscles. Thus, the purpose of this paper was to systematically review the literature on the electromyographic (EMG) activity of three core muscles (lumbar multifidus, transverse...

Firefighters are at increased risk for back injuries, which may be mitigated through exercise therapy to increase trunk muscle endurance. However, long-term adherence to exercise therapy is generally poor, limiting its potential benefits. Focus groups can be used to identify key barriers and facilitators to exercise adherence among study participan...

The purpose of this study was to assess the relationships between obesity and measures of back and core muscular endurance in firefighters. Methods. A cross-sectional study was conducted in career firefighters without low back pain. Obesity measures included body mass index (BMI) and body fat percentage assessed with air displacement plethysmograph...

The purpose of this study was to determine if ratio scaling or allometric scaling is the more appropriate method for normalising ultrasound measurements of lumbar multifidus and abdominal muscle size to body mass. In a convenience sample of 62 male career firefighters, cross-sectional area and thickness of the lumbar multifidus, as well as, thickne...

The primary purpose of this study was to derive allometric parameters for normalizing Biering-Sorensen and Plank Test scores (measures of isometric back and abdominal muscle endurance, respectively) to body mass. The secondary purpose was to determine if allometric scaling with derived allometric parameters or the theoretical allometric parameter (...

The purpose of this investigation was to assess the intrasession and intersession reliability of the Vertec, Just Jump System, and Myotest for measuring countermovement vertical jump (CMJ) height. Forty male and 39 female university students completed 3 maximal-effort CMJs during 2 testing sessions, which were separated by 24-48 hours. The height o...

The load that maximizes power output in the jump squat (JS) in college-aged athletic males has been reported to be 0% of 1 repetition maximum [1RM] squat strength) or in other words body mass. No data exist concerning adolescent athletic males. In addition, strength levels have been theorized to possibly affect the load that maximizes power output...

The maximal dynamic output (MDO) hypothesis is a newly proposed concept, which suggests that the muscular system of the lower limbs is designed to produce maximal power output when performing countermovement vertical jumping (CMJ) at body mass as opposed to other loading conditions. However, it is unclear if the MDO concept can be applied to indivi...

Previous investigations have examined power output in the jump squat in college-age subjects and it has been determined that the load at which jump squat peak power is maximized in this population is body mass. No data exists in the adolescent population. Additionally, few studies have examined the possible relationship between one repetition maxim...

The purpose of the current investigation was to assess the effect of an acute bout of whole body vibration (WBV) exercise on muscle force output and motor neuron excitability. Nineteen recreationally trained college-aged males were randomly assigned to a WBV (n = 10) or a sham (S, n = 9) group. The WBV group completed a series of static, body weigh...

The purpose of this investigation was to compare kinetic and kinematic variables between squats performed with and without elastic bands equalized for total work. Ten recreationally weight trained males completed 1 set of 5 squats without (Wht) and with (Band) elastic bands as resistance. Squats were completed while standing on a force platform wit...

The purpose of the current study was to determine the acute neuroendocrine response to hypertrophy (H), strength (S), and power (P) type resistance exercise (RE) equated for total volume. Ten male subjects completed three RE protocols and a rest day (R) using a randomized cross-over design. The protocols included (1) H: 4 sets of 10 repetitions in...

The primary purpose of this investigation was to provide a descriptive analysis of lower-body strength and vertical jump performance in overweight male (n = 8) and female (n = 13) adolescents. Maximal strength was tested in the leg press and isometric squat. Kinetic and kinematic variables were assessed in vertical jumps at various loads. When comp...

The purpose of this investigation was to compare 4 different methods of calculating volume when comparing resistance exercise protocols of varying intensities. Ten Appalachian State University students experienced in resistance exercise completed 3 different resistance exercise protocols on different days using a randomized, crossover design, with...

The ability of an athlete to generate high power outputs appears to be related to athletic performance and success in athletics. Additionally, improvements in poweroutput as a result of resistance training have been found to coincide with improvements inmeasures of athletic performance. Thus, determining the optimal way to train forincreased power...

The purpose of this investigation was to determine the relationship between countermovement vertical jump (CMJ) performance and various methods used to assess isometric and dynamic multijoint strength. Twelve NCAA Division I-AA male football and track and field athletes (age, 19.83 +/- 1.40 years; height, 179.10 +/- 4.56 cm; mass, 90.08 +/- 14.81 k...

The purpose of this investigation was to compare trunk muscle activity during stability ball and free weight exercises. Nine resistance-trained men participated in one testing session in which squats (SQ) and deadlifts (DL) were completed with loads of approximately 50, 70, 90, and 100% of one-repetition maximum (1RM). Isometric contractions during...

The purpose of this study was to compare mechanical efficiency between repeated static jumps (SJ), countermovement jumps (CMJ), drop jumps from 75% of maximum CMJ jump height (75DJ) and drop jumps from 125% of maximum CMJ height (125DJ). Subjects included eight jump-trained males. All subjects completed 30 continuous repetitions in the SJ, CMJ, 75D...