Zourdos, Michael C.

The purpose of this research was to investigate how accurate trained lifters were
at gauging intra-set rating of Perceived Exertion (RPE) in the squat, bench press, and
deadlift. Ten resistance-trained males completed four sets to failure with 80% of their
one-repetition maximum (1RM) and verbally indicated when they believed they were at a
“6” and “9” RPE. Across all sets and all lifts, the called 9 RPE was more accurate than
the called 6 RPE. Additionally, RPE calls were more accurate during set four vs. set one
on the squat and deadlift at both the called 6 and 9 RPEs. Further bench press RPE calls
were more accurate than squat and deadlift RPE at the called 6, while both bench and
deadlift RPE calls were more accurate than squat RPEs at the called 9. Importantly across
all sets all RPE calls assessed repetitions in reserve within one repetition of precision.

This research examined the time-course of muscle damage in the squat, bench
press, and deadlift. Ten resistance-trained males performed four sets to failure with 80%
of one-repetition maximum (1RM) for each exercise on three separate weeks. Swelling,
range of motion (ROM), delayed onset muscle soreness (DOMS), lactate dehydrogenase
(LDH), creatine kinase (CK), and average concentric velocity (ACV) were assessed pretraining
and at five timepoints post-training: -0, 24, 48, 72, and 96 hours. Swelling
(p<0.01) increased immediately post-training, and DOMS (p<0.01) increased at 24 hours
post-training in the bench press condition. Additionally, DOMS increased at 48 hours in
both squat and deadlift conditions (p<0.01). Squat and deadlift elevated CK immediately
post-training (p<0.01), but LDH only increased in the squat post-training. Immediately
post in the bench press ACV was decreased (p<0.01) along with in the squat for up to 72
hours (p<0.01), however, ACV did not change following the deadlift (p>0.05).

The purpose of the present study was to investigate if any relationship exists
between anthropometric measurements with average concentric velocity (ACV) at
various intensities in the back squat and the number of repetitions able to be
performed during a set to volitional fatigue at 70% of one-repetition maximum
(1RM). It was hypothesised that short femurs and total height would be related to
slower ACVs and lower total number of repetitions performed. 58 resistance trained
subjects were recruited and attended one day of data collection. Subjects performed
1RM testing of the back squat followed by two single repetition sets at 30-90% of
1RM and a 70% of 1RM set to fatigue. There was no significant correlation between
femur length and height with ACV at any intensity (p>0.05). A significant negative
correlation existed between both height (r=-0.39, p=0.003) and femur length (r=-0.31,
p=0.018) with total number of repetitions performed.

The purpose of this research was to investigate if various psychological wellbeing
assessments can predict maximal strength performance and self-scored rating of
perceived exertion (RPE) in the back squat. Fifty-eight resistance-trained males and
females were recruited, and reported to the laboratory on one day. Subjects completed
eight different scales and questionnaires before completing one-repetition maximum
(1RM) testing of the squat, followed by two single-repetition sets at 30%, 40%, 50%,
60%, 70%, 80%, and 90% of 1RM, and a set to volitional fatigue at 70% of 1RM.
Cognitive anxiety and hypersomnia were found to be positive and negative predictors
(p<0.05), respectively, of 1RM performance. Further, self-confidence, grit, and perceived
recovery status were significant negative predictors of RPE (p<0.05). Finally, PRS was
discovered to be a positive predictor of subject-reported 1RM self-efficacy (b=0.39,
t=3.14, p<0.01, R2=0.15).

The purpose of this study was to investigate the validity of linear position
transducers (LPTs), The Open Barbell System (OBS) and Tendo Weightlifting Analyzer
System (TWAS), in comparison to criterion measure Optotrak Certus (OC3D). Further,
we aimed to compare LPTs against each other. Twenty-five resistance-trained males were
recruited, and reported to the laboratory for one day of data collection. Subjects
performed one-repetition maximum (1 RM) testing of the squat, then had a standardized
rest before completing one set to failure with 70% 1 RM. There was no significant
difference in average velocity (AV) between either LPT vs. OC3D. T-tests revealed
significant differences between LPTs and OC3D peak velocity (PV) (OBS: p=0.02080;
TWAS: p<0.01). A significant difference was detected between OBS and TWAS PV
(p<0.01). OBS and TWAS demonstrated concurrent validity compared to OC3D for AV
(OBS: p=0.2014; TWAS: p=0.5466). Neither LPT was a valid measure ofPV (OBS:
p=0.0208; TWAS: p<0.01).

The purpose of this study was to examine the acute and temporal response of CK- MM and FGF-21 to 3-day/wk. different repetition-range, volume-equated resistance training programs over 8-weeks in previously trained males. Sixteen trained, college- aged males were counterbalanced into high (DUP-HR) or low (DUP-LR) repetition groups. Subjects performed the squat and bench press 3x/wk. for 8 weeks. Blood samples were collected at various intervals throughout the study. Trained individuals did not elicit significant acute or chronic changes in CK-MM or FGF-21 following training and the lack of change was present in both groups. Additionally, neither biomarker correlated with changes in 1RM strength. There was a very strong correlation between acute mean (r=0.95) and acute percentage change (r=0.97) increase from pre training to post training in week #1. Additionally, a moderate correlation in percentage change was observed (r=0.59) of both biomarkers from pre training to 48 hours post training in week #2.

The purpose of this study was to determine if barbell circuit training (RTC) as a model for concurrent training is superior to high intensity interval (CTHI) or moderate intensity continuous (CTMI) cycling for changes in muscular strength, hypertrophy, and body composition. Eleven trained males were recruited and counterbalanced into three groups. Each program featured three alternating days of resistance training per week, with one of the above time-equated (30-minute) concurrent training modalities between sessions. All groups increased muscular strength (p<0.05, RTC=7.48%, CTHI=10.32%, CTMI=15.74%) with no group differences (p>0.05). Increases in upper body muscle hypertrophy were similar in RTC and CTMI (p<0.01, RTC=20.18%, CTMI=20.97%), increases in lower body muscle hypertrophy only occurred in CTMI (VM: p=0.01, 38.59%, VLP: p=0.07, 13.33%), while no hypertrophy changes were detected in CTHI (p>0.05), no group experienced changes in body composition (p>0.05). These findings suggest similar muscle performance benefits from barbell circuit or cycling concurrent training.

The purpose of this study was to determine if resistance exercise altered
peripheral BDNF concentration. Eighteen trained male subjects were split into two
groups performing varied repetition ranges. DUP-HR and DUP-LR groups trained
3x/week for 8 weeks, and were equated for total volume (repetitions X sets X intensity).
Plasma BDNF and interleukin-6 (IL-6) levels were measured prior to and immediately
following the first exercise session of weeks 1, 2, 4 and 6. Pre-exercise levels were also
assessed prior to the second and third sessions of week 1 and 6. Lastly, resting levels
were measured before and after training intervention. No group differences (p>0.05) were detected for either biomarker. An acute BDNF elevation (p=0.018) was detected only in the final week of training. IL-6 elevations were detected at all acute measurements (p<0.01). BDNF and IL-6 percentage change correlated significantly (p<0.05) in week-1. No chronic alterations were observed (p>0.05).

Periodized training programs seem to augment muscle performance (i.e.,
hypertrophy, strength and muscle endurance), however, optimal repetition ranges to
achieve these adaptations are unclear. Thus, the purpose was to compare high and low
repetition daily undulating periodization (DUP) models, with equal volume on
performance. Eleven trained, college-aged males were counterbalanced into high (DUPHR) or low (DUP-LR) repetition groups. Subjects performed the squat and bench press 3X/wk. for 8wks. Outcome measures included one-repetition maximum (1RM) bench press, squat, and total strength (TS=squat+bench press), and muscle thickness (MT). 1RM strength increased with no difference between groups. Both groups increased total chest and total body MT (p<0.05); but only DUP-HR increased thigh MT (p<0.05). Effect sizes showed meaningful differences in strength favoring DUP-LR for bench press-1.48 and TS-0.89. Our findings indicate with equal volume, there may be meaningful differences in strength that are repetition-dependent, and varying responses to MT across different muscle groups.