Article

Number of repetitions performed before and after reaching velocity loss thresholds: first repetition vs. fastest repetition - mean velocity vs. peak velocity

Abstract and Figures

Purpose: To explore the effect of several methodological factors on the number of repetitions performed before and after reaching certain velocity loss thresholds (VLTs). Method: Fifteen resistance-trained men (bench press 1-repetition maximum = 1.25 [0.16] kg·kg-1) performed with maximum intent a total of 182 sets (77 short sets [≤12 repetitions] and 105 long sets [>12 repetitions]) leading to failure during the Smith machine bench press exercise. Fifteen percent, 30%, and 45% VLTs were calculated, considering 2 reference repetitions (first and fastest repetitions) and 2 velocity variables (mean velocity [MV] and peak velocity [PV]). Results: The number of repetitions performed before reaching all VLTs were affected by the reference repetition and velocity variable (P ≤ .001). The fastest MV and PV during the short sets (75.3%) and PV during the long sets (72.4%) were predominantly observed during the first repetition, while the fastest MV during long sets was almost equally distributed between the first (37.1%) and second repetition (40.0%). Failure occurred before reaching the VLTs more frequently using PV (4, 8, and 33 occasions for 15%, 30%, and 45% VLTs, respectively) than MV (only 1 occasion for the 45% VLT). The participants rarely produced a velocity output above a VLT once this threshold was exceeded for the first time (≈10% and 30% of occasions during the short and long sets, respectively). Conclusions: The reference repetition and velocity variable are important factors to consider when implementing VLTs during resistance training. The fastest repetition (instead of the first repetition) and MV (instead of PV) are recommended.
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Number of Repetitions Performed Before and After Reaching
Velocity Loss Thresholds: First Repetition Versus Fastest
RepetitionMean Velocity Versus Peak Velocity
Amador García-Ramos, Jonathon Weakley, Danica Janicijevic, and Ivan Jukic
Purpose:To explore the effect of several methodological factors on the number of repetitions performed before and after
reaching certain velocity loss thresholds (VLTs). Method:Fifteen resistance-trained men (bench press 1-repetition maximum =
1.25 [0.16] kg·kg
1
) performed with maximum intent a total of 182 sets (77 short sets [12 repetitions] and 105 long sets [>12
repetitions]) leading to failure during the Smith machine bench press exercise. Fifteen percent, 30%, and 45% VLTs were
calculated, considering 2 reference repetitions (rst and fastest repetitions) and 2 velocity variables (mean velocity [MV] and
peak velocity [PV]). Results:The number of repetitions performed before reaching all VLTs were affected by the reference
repetition and velocity variable (P.001). The fastest MV and PV during the short sets (75.3%) and PV during the long sets
(72.4%) were predominantly observed during the rst repetition, while the fastest MV during long sets was almost equally
distributed between the rst (37.1%) and second repetition (40.0%). Failure occurred before reaching the VLTs more frequently
using PV (4, 8, and 33 occasions for 15%, 30%, and 45% VLTs, respectively) than MV (only 1 occasion for the 45% VLT). The
participants rarely produced a velocity output above a VLT once this threshold was exceeded for the rst time (10% and 30% of
occasions during the short and long sets, respectively). Conclusions:The reference repetition and velocity variable are important
factors to consider when implementing VLTs during resistance training. The fastest repetition (instead of the rst repetition) and
MV (instead of PV) are recommended.
Keywords:bench press, fatigue, training prescription, velocity-based training
Resistance training (RT) is an effective method to induce
neuromuscular adaptations, which are benecial for both athletic
performance and health.
1,2
It is known that the neuromuscular
adaptations induced by RT strongly depend on the manipulation of
the RT program variables.
3
The intensity (i.e., load lifted), volume
(i.e., number of sets and repetitions performed), and lifting tempo
(i.e., maximal velocity or intentionally slower) are all critical
variables to consider when designing RT programs.
4,5
Therefore,
a recurring problem that practitioners must face is how to accu-
rately prescribe and monitor these variables. A viable solution that
is becoming increasingly popular among coaches and sport scien-
tists consists of the recording of movement velocity during RT
(i.e., velocity-based training).
6
Many studies have been conducted
to rene the procedure for establishing the relationship between
movement velocity and the relative load (i.e., percentage of the
1-repetition maximum [1RM]).
712
The available literature sug-
gests that individualized loadvelocity proles (instead of group-
averaged loadvelocity proles), mean velocity (MV) values
(instead of other velocity variables, such as peak velocity [PV]
or mean propulsive velocity [MPV]), and linear regressions (instead
of polynomial regression models) allow for a more accurate pre-
scription of relative loads during RT.
712
However, there is less
scientic evidence on how movement velocity should be used to
prescribe the training volume (i.e., number of sets and repetitions).
Before the emergence of velocity-based training, the most
common approach was to assign a xed predetermined number of
repetitions for all individuals during sets performed against the
same relative loads (%1RM).
13
However, given that the number of
repetitions that can be completed with a xed %1RM is both
subject- and exercise-dependent,
14
assigning a xed number of
repetitions can result in different levels of effort experienced by
individuals. Three different approaches have been proposed within
the velocity-based training literature to solve this problem: (1) stop-
ping the training set when a relative velocity loss threshold (VLT)
is reached (e.g., 20% reduction in repetition velocity),
1517
(2) stop-
ping the training set when an absolute velocity threshold is reached
(e.g., 0.35 m·s
1
),
18,19
and (3) determining the relationship between
the initial velocity of the set and the maximum number of repeti-
tions that can be completed before failure.
19
The vast majority of velocity-based training intervention
studies have used VLTs to prescribe the volume of training.
16,20,21
An important point to consider is that the number of repetitions
performed before reaching a given VLT could be affected by
methodological factors, such as the reference repetition (rst
and fastest repetition of the set) or the velocity variable of choice
(MV, MPV, and PV). Note that the initial repetition of the set might
not always be the fastest,
22,23
a reduction in the ability to apply
force at the beginning of the concentric phase should affect more
MV and MPV than PV, and the differences between MV and MPV
tend to increase as the movement velocity increases.
24
However,
García-Ramos is with the Dept of Physical Education and Sport, Faculty of Sport
Sciences, University of Granada, Granada, Spain; and the Dept of Sports Sciences
and Physical Conditioning, Faculty of Education, Universidad Cato´lica de la
Santísima Concepcio´n, Concepcio´n, Chile. Weakley is with the School of Beha-
vioural and Health Sciences, Australian Catholic University, Brisbane, QLD,
Australia; and Carnegie Applied Rugby Research (CARR) Centre, Inst for Sport,
Physical Activity and Leisure, Leeds Beckett University, Leeds, United Kingdom.
Janicijevic is with the Faculty of Sports Science, Ningbo University, Ningbo, China;
and the University of Belgrade, Faculty of Sport and Physical Education, The
Research Center, Belgrade, Serbia. Jukic is with the Sports Performance Research
Inst New Zealand (SPRINZ), Auckland University of Technology, Auckland, New
Zealand. García-Ramos (amagr@ugr.es) is corresponding author.
1
International Journal of Sports Physiology and Performance, (Ahead of Print)
https://doi.org/10.1123/ijspp.2020-0629
© 2021 Human Kinetics, Inc. ORIGINAL INVESTIGATION
to our knowledge, no study has examined whether the reference
repetition or the velocity variable has an effect on the number of
repetitions performed before exceeding a given VLT.
The use of VLTs is justied by the close relationship between the
relative loss of velocity in a set and the percentage of repetitions
performed with respect to the total number of repetitions that can be
completed before muscular failure.
17,25
In this regard, several equa-
tions have been proposed to predict the percentage of performed
repetitions from VLTs in exercises such as the bench press,
17
pull-
up,
25
andbacksquat.
26
However, an important point is that the
experimental sessions of these studies consisted of a single set of
repetitions to failure, which is not common in practice where multiple
sets of the same exercise are frequently performed. Although it is
known that performing successive sets of the same exercise may
decrease the number of repetitions performed before reaching mus-
cular failure regardless of the interset rest periods,
27
no study has
explored whether the number of repetitions performed before reach-
ing a given VLT could also be affected by the number of sets
performed. Furthermore, all the aforementioned studies have analyzed
MPV, and no study has established this relationship for MV or PV.
Therefore, given that MV and PV are extensively used in research and
practice,
6
it is important to elucidate whether the relationship between
the percentage of completed repetitions and the magnitude of velocity
loss remains stable when MV and PV are considered.
To address the research gaps outlined above, the velocity data
of 182 sets leading to failure were collected during the Smith
machine bench press exercise in a group of resistance-trained men.
The primary objective of this study was to elucidate whether the
number of repetitions performed before reaching a certain VLT is
affected by the reference repetition (rst vs fastest repetition of
the set) and the velocity variable (MV vs PV). The secondary
objectives were (1) to determine the repetition number in which
the fastest MV and PV were obtained, (2) to explore the number
of occasions in which the subjects reached failure before reaching
the 15%, 30%, and 45% VLTs, (3) to determine the individual
variability in the percentage of completed repetitions before
exceeding the 15%, 30%, and 45% VLTs with respect to the total
number of repetitions completed, and (4) to report the number of
times that the subjects were able to produce an MV or PV above a
VLT once this threshold was exceeded for the rst time.
Method
Subjects
Fifteen resistance-trained men (age = 23.5 [2.2] y, body mass =
74.6 [8.2] kg, body height = 1.76 [0.08] m, touch-and-go bench
press 1RM = 92.6 [12.7] kg, 1.25 [0.16] kg·kg
1
) participated in
this study. All subjects had at least 2 years of RT experience (4.9
[2.1] y) and reported to be experienced with both lifting at maximal
velocity and lifting to failure. The subjects did not report any injury
or discomfort that could affect bench press performance. All
subjects signed a written informed consent form before the com-
mencement of the study. The study protocol adhered to the tenets of
the Declaration of Helsinki and was approved by the University of
Granada review board.
Study Design
A descriptive study was conducted to explore the effect of several
methodological factors on the number of repetitions performed be-
fore and after reaching certain VLTs. All subjects were recreational
lifters of a local gym. Data collection took place during a 3-week
period in which the subjects followed their regular training. Only
the sets performed to failure and with maximal intent from the rst
to the last repetition during the Smith machine bench press exercise
were considered in the present study. Although all subjects re-
ported to have experience with sets to failure during the Smith
machine bench press exercise, the rst session for each subject only
served for familiarization purposes.
A total of 182 sets were recorded. The number of sets per-
formed by each subject ranged from 7 to 17. The subjects were
allowed to self-select the loads, and only the sets with a repetition
range between 6 and 30 were considered for statistical analyses.
For comparative purposes, the sets were divided into 2 groups:
short sets (12 repetitions; 77 sets) and long sets (>12 repetitions;
105 sets). The bench press has been a staple exercise for both
testing and training the upper body strength and power of ath-
letes in many professional sports.
28,29
Short sets (XRM <12 or
%1RM >70%1RM) are commonly used to increase maximal
strength and promote hypertrophy, while longer sets (XRM >12
or %1RM <70%1RM) can be useful to develop the ability to repeat
maximal power production when the successive repetitions of the
set are performed with maximal intent.
Procedures
The warm-up, external loads, number of sets, grip width, and
length of the interset rest periods were self-selected by the parti-
cipants as they commonly do in their usual training. The bench
press was the only exercise assessed in this study, and it was
performed in a Fttech Smith Machine (Fttech, Taiwan, China)
using the touch-and-go technique.
19
The subjects were allowed
to include the Smith machine bench press exercise at any time of
their training. The subjects were strongly encouraged to perform
all repetitions of the bench press exercise as fast as possible and
to complete the maximum possible number of repetitions before
reaching muscular failure. The subjects were forbidden to rest
between successive repetitions. A validated linear velocity trans-
ducer (T-Force System; Ergotech, Murcia, Spain) was attached to
the bar of the Smith machine and sampled the velocitytime data
at a frequency of 1000 Hz.
30
The MV and PV of all repetitions were
collected. The 15%, 30%, and 45% VLTs were computed consid-
ering the velocity of the rst repetition and fastest repetition of
the set. These VLTs (15%, 30%, and 45%) could be associated
with low, medium, and high levels of fatigue, respectively.
Statistical Analyses
The descriptive data are presented as means (SDs), while the CV
is indicated as the median value and range. The ShapiroWilk
test revealed a violation of the normal distribution assumption for
all variables (P>.05). Consequently, the Friedman test was used
to explore the differences among the conditions (fastest MV, rst
MV, fastest PV, and rst PV) on (1) the number of repetitions
performed (expressed in absolute values and as a percentage of the
total number of repetitions completed in the set) before reaching
the 15%, 30%, and 45% VLTs and (2) the number of times that
the subjects produced an MV or PV above the 15%, 30%, and
45% VLTs after these VLTs were reached for the rst time. The
Wilcoxon signed-rank test with Bonferroni post hoc corrections
was used for pairwise comparisons. Statistical analyses were per-
formed using the software package SPSS (version 25.0; IBM Corp,
Chicago, IL). Statistical signicance was set at P<.05.
(Ahead of Print)
2García-Ramos et al
Results
During the short sets (12 repetitions), the fastest MV and PV were
always observed among the rst 3 repetitions (rst repetition =
75.3%, second repetition = 22.1%, third repetition = 2.6%;
Table 1). During long sets (>12 repetitions), the fastest PV was
also predominantly observed at the rst repetition (72.4%), but the
fastest MV was almost equally distributed between the rst
(37.1%) and second repetition (40.0%).
Considering the MV values, the subjects never reached failure
before reaching the 15% and 30% VLTs, and only in one occasion
did they reach failure before reaching the 45% VLT (Table 2).
However, considering the PV of the rst repetition, the subjects
reached failure before the 15%, 30%, and 45% VLTs on 4, 8, and
33 occasions, respectively.
The Friedman tests revealed a signicant effect of the condi-
tion (fastest MV, rst MV, fastest PV, and rst PV) on the number
of repetitions performed before reaching all VLTs for both the
long and short sets (P.001; Table 3and Figure 1). The number
of repetitions performed before reaching the 15%, 30%, and
45% VLTs was higher for PV than for MV during the short sets,
but it was higher for MV than for PV during the long sets. The
use of the rst repetition as the reference repetition resulted in a
greater number of repetitions performed before reaching all VLTs
Table 1 Repetition Number at Which the Fastest Velocity Output Was Achieved
12 repetitions
(n = 77)
>12 repetitions
(n = 105)
All
(N = 182)
Repetition MV PV MV PV MV PV
1 58 (75.3%) 58 (75.3%) 39 (37.1%) 76 (72.4%) 97 (53.3%) 134 (73.6%)
2 17 (22.1%) 17 (22.1%) 42 (40.0%) 24 (22.9%) 59 (32.4%) 41 (22.5%)
3 2 (2.6%) 2 (2.6%) 13 (12.4%) 3 (2.9%) 15 (8.2%) 5 (2.7%)
4 0 (0.0%) 0 (0.0%) 6 (5.7%) 1 (1.0%) 6 (3.3%) 1 (0.5%)
5 0 (0.0%) 0 (0.0%) 4 (3.8%) 0 (0.0%) 4 (2.2%) 0 (0.0%)
6 0 (0.0%) 0 (0.0%) 1 (1.0%) 1 (1.0%) 1 (0.5%) 1 (0.5%)
Abbreviations: MV, mean velocity; PV, peak velocity.
Table 2 Number of Occasions in Which Participants Reached Failure Before Reaching the 15%, 30%, and 45%
Velocity Loss Thresholds
12 repetitions (n = 77) >12 repetitions (n = 105) All (N = 182)
Reference
repetition Variable 15% 30% 45% 15% 30% 45% 15% 30% 45%
First MV —— 1————— 1
PV 3 6 21 1 2 12 4 8 33
Fastest MV —— 1————— 1
PV 2 6 20 1 2 11 3 8 31
Abbreviations: MV, mean velocity; PV, peak velocity.
Table 3 Number of Repetitions Performed Before Reaching the 15%, 30%, and 45% Velocity Loss Thresholds
12 repetitions (n = 77) >12 repetitions (n = 105) All (N = 182)
Reference
repetition Variable 15% 30% 45% 15% 30% 45% 15% 30% 45%
First MV 4.1 (1.4)
[28]
33.7%
6.3 (1.4)
[39]
22.1%
8.0 (1.5)
[511]
18.5%
8.3 (3.1)
[219]
36.7%
12.8 (3.5)
[522]
27.2%
15.8 (3.3)
[925]
21.0%
6.5 (3.2)
[219]
49.8%
10.0 (4.3)
[322]
42.5%
12.5 (4.7)
[525]
37.7%
PV 4.5 (1.7)
[29]
38.5%
6.8 (1.9)
[212]
28.3%
8.1 (1.9)
[212]
23.0%
6.2 (2.3)
[214]
36.3%
11.0 (2.9)
[624]
26.4%
15.2 (3.5)
[727]
23.1%
5.5 (2.2)
[214]
40.3%
9.2 (3.3)
[224]
35.7%
12.2 (4.6)
[227]
37.5%
Fastest MV 4.0 (1.2)
[28]
31.0%
6.2 (1.3)
[39]
21.4%
8.0 (1.5)
[511]
18.6%
7.3 (2.4)
[214]
32.7%
12.1 (3.2)
[522]
26.4%
15.4 (3.2)
[925]
20.8%
5.9 (2.6)
[214]
43.7%
9.6 (3.9)
[322]
40.7%
12.3 (4.5)
[525]
36.8%
PV 4.2 (1.5)
[28]
34.9%
6.7 (1.9)
[212]
28.3%
8.1 (1.9)
[212]
23.1%
5.8 (1.9)
[213]
32.1%
10.7 (2.6)
[619]
24.5%
15.0 (3.4)
[727]
22.9%
5.1 (1.9)
[213]
36.6%
9.0 (3.1)
[219]
34.0%
12.1 (4.5)
[227]
37.2%
Abbreviations: MV, mean velocity; PV, peak velocity. Note: Values are presented as mean (SD), [range], and coefcient of variation.
(Ahead of Print)
Factors Affecting Velocity Loss Thresholds 3
compared with using the fastest repetition, with the differences
being accentuated for the short sets. Regardless of the reference
repetition, velocity variable, and length of the set, the variability in
the number of repetitions performed before reaching the VLTs was
always high (median coefcient of variance CV [range] = 26.4%
[18.5%38.5%]).
The Friedman tests revealed signicant differences between
the conditions (fastest MV, rst MV, fastest PV, and rst PV) on
the percentage of completed repetitions with respect to the maxi-
mum before exceeding the 15%, 30%, and 45% VLTs in both the
long and short sets (P.001; Table 4and Figure 2). The percentage
of completed repetitions before reaching all VLTs was higher for
PV than for MV during the short sets, but it was higher for MV than
for PV during the long sets. Using the rst repetition as the
reference, repetition resulted in a greater percentage of completed
repetitions for all VLTs than using the fastest repetition, with the
differences being accentuated for the short sets. The variability in
the percentage of repetitions performed with respect to the total
number of repetitions completed was high for all VLTs and
decreased for higher VLTs: 15% VLT (32.2% [26.2%41.1%]),
30% VLT (19.1% [14.9%23.6%], and 45% VLT (12.8%
[9.9%15.6%]).
The subjects rarely produced an MV or PV above a VLT once
this threshold was exceeded for the rst time (10% and 30% of
occasions during the short and long sets, respectively; Table 5and
Figure 3). However, the Friedman tests revealed signicant differ-
ences between the conditions during the short sets for the 15% VLT
(P= .002) and 30% VLT (P= .26) and during the long sets for the
45% VLT (P= .020). The signicant differences were caused by
the higher number of repetitions performed above the VLTs,
considering PV compared with MV. However, no signicant
differences were observed during the short sets for the 45%
VLT (P= 1.000) and during the long sets for the 15% VLT
(P= .965) and 30% VLT (P= .911).
Discussion
This study was designed to explore the effect of the reference
repetition (rst repetition vs fastest repetition) and the velocity
variable (MV vs PV) on the number of repetitions performed before
and after reaching 15%, 30%, and 45% VLTs. This study revealed
5 main ndings. First, the fastest MV and PV during the short sets
(12 repetitions) and PV during the long sets (>12 repetitions) were
predominantly observed at the rst repetition, while the fastest MV
during the long sets was almost equally distributed between the rst
Figure 1 Number of repetitions performed before reaching the 15%,
30%, and 45% velocity loss thresholds during (A) short sets (12
repetitions) and (B) long sets (>12 repetitions) (P<.05 with Bonferroni
correction). SDs are depicted in Table 3. MV indicates mean velocity; PV,
peak velocity.
a
Signicantly higher than fastest MV.
b
Signicantly higher
than rst MV.
c
Signicantly higher than fastest PV.
d
Signicantly higher
than rst PV.
Table 4 Percentage of Completed Repetitions Before Exceeding the 15%, 30%, and 45% Velocity Loss Thresholds
With Respect to the Total Number of Repetitions Completed in the Set
12 repetitions (n = 77) >12 repetitions (n = 105) All (N = 182)
Reference
repetition Variable 15% 30% 45% 15% 30% 45% 15% 30% 45%
First MV 45.6 (12.7)
[1880]
27.9%
70.1 (11.2)
[43100]
16.0%
89.6 (9.4)
[64100]
10.5%
44.0 (13.0)
[1373]
29.4%
67.1 (11.6)
[3886]
17.3%
83.7 (8.3)
[55100]
9.9%
44.7 (12.8)
[1380]
28.7%
68.4 (11.5)
[38100]
16.8%
86.2 (9.2)
[55100]
10.7%
PV 50.8 (18.8)
[18100]
37.0%
75.7 (17.6)
[22100]
23.3%
90.6 (14.0)
[22100]
15.4%
33.8 (13.9)
[12100]
41.1%
58.6 (12.7)
[33100]
21.7%
80.6 (11.8)
[54100]
14.6%
41.0 (18.2)
[12100]
44.3%
65.9 (17.2)
[22100]
26.1%
84.8 (13.7)
[22100]
16.1%
Fastest MV 44.4 (11.6)
[1867]
26.2%
69.0 (10.3)
[4389]
14.9%
89.5 (9.3)
[64100]
10.4%
39.0 (11.4)
[1362]
29.3%
63.9 (11.0)
[3886]
17.2%
81.9 (9.1)
[41100]
11.1%
41.3 (11.8)
[1367]
28.5%
66.1 (11.0)
[3889]
16.6%
85.1 (9.9)
[41100]
11.6%
PV 47.8 (16.8)
[18100]
35.1%
75.2 (17.7)
[22100]
23.6%
90.3 (14.1)
[22100]
15.6%
31.8 (12.8)
[12100]
40.2%
57.3 (12.0)
[33100]
21.0%
79.8 (11.7)
[54100]
14.6%
38.6 (16.6)
[12100]
42.9%
64.9 (17.1)
[22100]
26.4%
84.3 (13.7)
[22100]
16.3%
Abbreviations: MV, mean velocity; PV, peak velocity. Note: Values are presented as mean (SD), [range], and coefcient of variation.
(Ahead of Print)
4García-Ramos et al
and second repetition. Second, MV detects the progressive devel-
opment of fatigue during a set more precisely than PV. Third, the
number of repetitions performed (expressed in absolute values, as
well as a percentage of the completed repetitions) before reaching
the different VLTs was higher for PV than for MV during the short
sets, higher for MV than for PV during the long sets, and higher
using the rst repetition than using the fastest repetition as the
reference repetition during both the short and long sets. Fourth, the
interindividual variability in the percentage of repetitions performed
before exceeding the VLTs, with respect to the total number of
repetitions completed, was generally high and accentuated for lower
VLTs (15% >30% >45%). Fifth, the number of repetitions during
Figure 3 Percentage of completed repetitions before exceeding the
15%, 30%, and 45% velocity loss thresholds with respect to the total
number of repetitions completed during (A) short sets (12 repetitions) and
(B) long sets (>12 repetitions) (P<.05 with Bonferroni correction). SDs
are depicted in Table 4. MV indicates mean velocity; PV, peak velocity.
a
Signicantly higher than fastest MV.
b
Signicantly higher than rst MV.
c
Signicantly higher than fastest PV.
d
Signicantly higher than rst PV.
Figure 2 Number of repetitions performed above the 15%, 30%, and
45% velocity loss thresholds after reaching, for the rst time, this threshold
during (A) short sets (12 repetitions) and (B) long sets (>12 repetitions).
SDs are depicted in Table 5. Wilcoxon signed-rank test did not reveal
signicant differences (P>.05 with Bonferroni correction). MV indicates
mean velocity; PV, peak velocity.
Table 5 Additional Number of Repetitions Performed Above the Thresholds After Reaching, for the First Time,
the 15%, 30%, and 45% Velocity Loss Thresholds
12 repetitions (n = 77) >12 repetitions (n = 105) All (N = 182)
Reference
repetition Variable 15% 30% 45% 15% 30% 45% 15% 30% 45%
First MV 0.1 (0.3)
[02]
0.0 (0.2)
[01]
0.1 (0.3)
[02]
0.4 (1.0)
[04]
0.2 (0.6)
[04]
0.1 (0.4)
[02]
0.3 (0.8)
[04]
0.1 (0.5)
[04]
0.1 (0.4)
[02]
PV 0.3 (0.9)
[06]
0.1 (0.5)
[03]
0.1 (0.5)
[03]
0.5 (1.3)
[08]
0.3 (1.0)
[07]
0.4 (0.9)
[04]
0.4 (1.2)
[08]
0.2 (0.9)
[07]
0.3 (0.8)
[04]
Fastest MV 0.1 (0.3)
[02]
0.0 (0.2)
[01]
0.1 (0.3)
[02]
0.4 (0.9)
[04]
0.2 (0.6)
[04]
0.1 (0.4)
[02]
0.3 (0.7)
[04]
0.1 (0.5)
[04]
0.1 (0.4)
[02]
PV 0.3 (0.8)
[05]
0.1 (0.5)
[03]
0.1 (0.5)
[03]
0.4 (1.0)
[05]
0.2 (0.8)
[06]
0.4 (0.9)
[04]
0.4 (1.0)
[05]
0.2 (0.7)
[06]
0.3 (0.8)
[04]
Abbreviations: MV, mean velocity; PV, peak velocity. Note: Values are presented as mean (SD) and [range].
(Ahead of Print)
Factors Affecting Velocity Loss Thresholds 5
which the velocity output was above the VLT once this threshold
was exceeded for the rst time was low, but it was generally higher
for PV compared to MV.
The main nding of this study is that, when the volume of RT
sets is prescribed using VLTs, the actual number of repetitions
performed may differ depending on the reference repetition and the
velocity variable from which the VLT is calculated. For instance,
during sets in which more than 12 repetitions can be performed,
on average, the subjects performed 43% more repetitions before
reaching the 15% VLT when this threshold was computed, con-
sidering the rst repetition and MV (8.3 repetitions) compared
with considering the fastest repetition and PV (5.8 repetitions).
However, the differences in the number of repetitions performed
before reaching the VLTs is reduced during sets in which <12
repetitions can be performed before reaching muscular failure.
Several studies have recommended specic VLTs (e.g., 10%, 20%,
and 30%) to provoke specic acute perceptual, mechanical, and
metabolic responses and, consequently, selectively inuence the
long-term adaptations induced by RT.
15,31
While this method has
been found to induce reliable internal fatigue responses, the present
study expands upon the existing literature on VLTs and highlights
that a given VLT would be associated with a different number of
repetitions based on the reference repetition and velocity variable
of choice.
The subjects completed a lower number of repetitions before
reaching the different VLTs using the fastest repetition as a ref-
erence compared with using the rst repetition. This result was
expected because the rst repetition was not always the fastest
repetition, especially when the MV was recorded during long sets
in which, in less than 50% of the sets, the rst repetition was the
fastest. Garcia-Ramos et al
22
also showed that the highest PV in
the bench press throw exercise was not always observed during the
rst repetition, especially when light loads and interrepetition rest
periods were implemented. Similarly, Jukic and Tufano
23
found
that the fastest or most powerful repetition during clean pulls at
various loads generally occurred during repetitions 1 to 3, while
some of the subjects had their fth repetition as their best. The use
of light loads and intraset rest periods should alleviate fatigue, and
therefore, the chance of obtaining the fastest velocity after the rst
repetition is increased. The fastest repetition of the set should be
recommended for computing VLTs to avoid the accumulation of an
excessive number of repetitions caused by a low-velocity perfor-
mance during the rst repetition.
The number of repetitions performed before reaching the 15%,
30%, and 45% VLTs was higher for PV than for MV during the
short sets and higher for MV than for PV during the long sets.
Although these 2 velocity variables are the most commonly used in
practice and research,
32,33
the vast majority of studies using VLTs
have considered the MPV.
17,25,26
Our results clearly show that the
velocity variable is an important factor to consider when prescrib-
ing the training volume using VLTs. The ndings of our study
suggest that MV could be more appropriate than PV because
(1) subjects reached failure before reaching the 15%, 30%, and
45% VLTs in more occasions using PV than MV, (2) the number of
times that the subjects produced a velocity output above a VLT
once this threshold was exceeded for the rst time was higher for
PV compared with MV, and (3) the interindividual variability in the
percentage of completed repetitions with respect to the total num-
ber of repetitions when a VLT is reached was higher for PV
(CV = 28.7%) than for MV (CV = 18.8%). Finally, although it was
not analyzed in the present study, it should be noted that the num-
ber of repetitions that can be performed before reaching a given
VLT should be lower (or the same) when using MPV compared
with MV because the difference between MV and MPV are
accentuated at faster movement velocities.
24
The use of VLTs has been justied by the close relationship
between VLTs and the percentage of repetitions performed with
respect to the total number of repetitions that can be completed
before muscular failure.
17,25
Several equations have been pro-
posed to predict the percentage of completed repetitions from
VLTs in different exercises when using MPV.
17,25,26
It is impor-
tant to note that, considering the MV in our study, we observed a
higher percentage of completed repetitions with respect to the
total number of repetitions before exceeding all VLTs in compar-
ison with the results reported by González-Badillo et al
17
in the
bench press exercise considering MPV (15% VLT: 44.7% vs
31.2%; 30% VLT: 68.4% vs 52.8%; 45% VLT: 86.2% vs 70.7%).
These results suggest that MV and MPV should not be used
interchangeably when prescribing the RT volume through VLTs.
Furthermore, while González-Badillo et al
17
showed a low inter-
individual variability (average CV = 8.9%) in the percentage of
completed repetitions with respect to the maximum when a given
VLT is reached, the interindividual variability in our study was
more than twice as large (average CV for MV = 18.8%). The
discrepancies in the interindividual variability between the studies
are surprising, but they could be at least partially explained by the
use of different velocity variables (MPV vs MV) or testing
protocols (a single set vs multiple sets in a real training session).
In agreement with González-Badillo et al,
17
(CV = 11.0% for the
15% VLT, 8.8% for the 30% VLT, and 6.9% for the 45% VLT),
we also observed a greater interindividual variability for lower
VLTs (CV for MV = 28.6% for the 15% VLT, 16.7% for the 30%
VLT, and 11.2% for the 45% VLT). Future studies should expand
this line of research to obtain more robust information about the
interindividual variability in the number of completed repetitions
when a VLT is reached. Therefore, it could be important to
elucidate whether the VLTs prescribed should be subject specic
in order to induce specic adaptations.
An important characteristic of the present study is that the
subjects were allowed to self-select a number of factors, such as the
warm-up, external loads, number of sets, grip width, and length of
the interset rest periods. This was done to increase the ecological
validity of the study, as not all individuals perform the same warm-
up or use the same interset rest periods in real training environ-
ments. However, failing to standardize these factors could also
be seen as a limitation because they are known to inuence RT
performance, and we cannot rule out the possibility that this
affected the results of the present study. Therefore, it is important
that future studies examine the selective inuence of these factors
on the number of repetitions performed before reaching certain
VLTs, as well as the use of VLTs in other exercises and free-weight
variants of the bench press exercise. Finally, it is important to note
that our subjects were instructed to perform all repetitions within
a set as fast as possible, without any rest between successive
repetitions. Therefore, the ndings of the present study might not
be applicable in situations where other pacing strategies are used.
Practical Applications
The fastest repetition of the set (instead of the rst repetition) and
MV (instead of PV) should be recommended when implementing
VLT during RT. The procedure of selecting the fastest repetition
could be simplied, considering the fastest velocity of the rst 3
repetitions during sets performed against light loads (>12RM), the
(Ahead of Print)
6García-Ramos et al
fastest velocity of the rst 2 repetitions during sets performed
against moderate loads (612RM), and the rst repetition during
sets performed against heavy loads (5RM). This is justied be-
cause the higher the load (i.e, lower number of repetitions that can
be performed), the more difcult it is to achieve the fastest
repetition after the rst repetition.
Conclusions
The number of repetitions performed before reaching a specic
VLT is inuenced by the reference repetition and velocity variable.
The rst repetition is not always the fastest, especially during sets
performed against light loads (13RM) and when MV is used. MV
should be used instead of PV due to a higher precision in detect-
ing the progressive development of fatigue during a set. This is
evidenced by the participantsreaching failure before exceeding
the VLTs in more occasions using PV, participantsproducing a
velocity output above a VLT once this threshold was exceeded for
the rst time in more occasions using PV, and MV demonstrating
a lower interindividual variability in the percentage of completed
repetitions with respect to the total number of repetitions when a
VLT is reached. However, regardless of the reference repetition
and velocity variable, the interindividual variability in the percent-
age of completed repetitions with respect to the total number of
repetitions was high. This high interindividual variability in the
percentage of completed repetitions when a VLT is reached sug-
gests that subject-specic VLTs may be more appropriate to induce
specic long-term training adaptations.
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(Ahead of Print)
8García-Ramos et al
... In some cases, strength and conditioning practitioners may choose to use the first repetition of a set as the baseline measure to which all other repetitions are compared, but others may choose to use the fastest repetition, regardless of where it occurs during the set. 6,7,16 Although studies have used each of these independently, there is a lack of research that directly compares how each of these can affect real-life training decisions if velocity-loss thresholds are used. Furthermore, velocity-loss is often described as a decrease in performance (ie, velocity decline), which can be quite extreme in some cases when performance declines quickly near the end of an exercise set. ...
... These findings agree with a recent study that showed that, when using the first compared with the fastest repetition as the reference, more repetitions could be performed before exceeding a given velocity loss threshold. 7 In addition, previous studies have also shown that the first repetition was not always the fastest, 6,7,16 which was also confirmed in the present study. For instance, while examining deadlift condition × repetition interaction ( Figure 5), it can be seen that the second repetition was also the fastest, on average, across the conditions. ...
... These findings agree with a recent study that showed that, when using the first compared with the fastest repetition as the reference, more repetitions could be performed before exceeding a given velocity loss threshold. 7 In addition, previous studies have also shown that the first repetition was not always the fastest, 6,7,16 which was also confirmed in the present study. For instance, while examining deadlift condition × repetition interaction ( Figure 5), it can be seen that the second repetition was also the fastest, on average, across the conditions. ...
Article
Background Using lifting straps during pulling exercises (such as deadlift) may increase absolute velocity performance. However, it remains unclear whether lifting straps could also reduce the degree of relative fatigue measured by velocity decline and maintenance in a training set. Hypothesis There will be less mean velocity decline (MVD) and greater mean velocity maintenance (MVM) for deadlifts performed with (DLw) compared with without (DLn) lifting straps, and an underestimation of MVD and MVM when using the first compared with the fastest repetition as a reference repetition. Study Design Randomized cross over design. Level of Evidence Level 3. Methods A total of 16 resistance-trained men performed a familiarization session, 2 1-repetition maximum [1RM] sessions (1 with and 1 without lifting straps), and 3 randomly applied experimental sessions consisting of 4 sets of 4 repetitions: (1) DLw against the 80% of DLn 1RM (DLwn), (2) DLn against the 80% of the DLn 1RM (DLnn), and (3) DLw against the 80% of the DLw 1RM (DLww). MVD and MVM were calculated using the first and the fastest repetition as the reference repetition. Results MVD was significantly lower during DLwn and DLnn compared with DLww ( P < 0.01), whereas MVM was greater during DLwn and DLnn compared with DLwn ( P < 0.01) with no differences between DLwn and DLnn for both MVD and MVM ( P > 0.05). The second repetition of the set was generally the fastest (54.1%) and lower MVD and higher MVM were observed when the first repetition was used as the reference repetition ( P < 0.05). Conclusions Lifting straps were not effective at reducing MVD and increasing MVM when the same absolute loads were lifted. Furthermore, using the first repetition as the reference repetition underestimated MVD, and overestimated MVM. Clinical relevance The fastest repetition should be used as the reference repetition to avoid inducing excessive fatigue when the first repetition is not the fastest.
... [11]. However, more recently, García-Ramos et al. [30] reported a considerable amount of inter-individual variability for the percentage of completed repetitions with respect to the XRM before exceeding a predetermined VLT in the Smith machine BP exercise (CV = 18.8%). These conflicting findings highlight the need for further research on this topic. ...
... The current study aimed to examine: (I) the effects of the grip width on XRM and XVTL (15%, 30%, and 45%) as well as slowest (MVslowest) and fastest (MVfastest) repetition in the set; (II) the association between different grip widths for XRM and XVLT, as well as between XRM and XVLT separately for each grip width; (III) the effects of relative strength and anthropometric characteristics on XRM and XVLT; and (IV) the inter-individual variability in the percentage of completed repetitions with respect to the XRM when the number of repetitions is prescribed based on FNR and VLT. Based on the findings of previous studies [11,25,27,30], we hypothesized that: (I) the XRM, XVTL, as well as MVslowest and MVfastest in the set would not be affected by the grip width; (II) significant correlations would be detected between the different grip widths for XRM and XVLTs, as well as between XRM and XVLTs for each grip width; (III) neither the relative strength nor the anthropometric characteristics would be significantly correlated with the XRM or XVLT; and (IV) a lower inter-individual variability in the percentage of completed repetitions with respect to the XRM would be observed using VLTs compared to a FNR. ...
... Even more important is the fact that the equipment (machine-based vs. free-weight movement) used to perform the BP exercise does not appear to influence the reported findings, but caution should be taken due to the methodological differences between the studies. Furthermore, García-Ramos et al. [30] has recently shown that MVfastest was predominantly observed during the 1st repetition (53%) and 2nd repetition (32%) and that individuals sometimes produced a velocity output above a VLT once this threshold is exceeded for the first time (on 0 to 4 occasions for 15% and 30% VLTs, and on 0 to 2 occasions for 45% VLT). In the present study, and in agreement with the findings by García-Ramos et al. [30], MVfastest was also predominantly observed during the 1st repetition (63%) and 2nd repetition (28%). ...
Article
Full-text available
This study aimed (I) to compare the number of repetitions that can be completed to failure (XRM) and before reaching a 15%, 30%, or 45% velocity loss threshold (XVLT) in the bench press exercise performed using different grip widths, and (II) to examine the inter-individual variability in the percentage of completed repetitions with respect to the XRM when the set volume is prescribed based on a fixed number of repetitions (FNR) and several velocity loss thresholds (VLT). Nineteen men performed four separate sessions in a random order where there was a single set of repetitions completed to failure against 75% of the one-repetition maximum during the Smith machine bench press exercise using a narrow, medium, wide, or self-selected grip widths. The XRM (p = 0.545) and XVLTs (p ≥ 0.682) were not significantly affected by grip width. A high and comparable inter-individual variability in the percentage of completed repetitions with respect to the XRM was observed when using both an FNR (median CV = 24.3%) and VLTs (median CV = 23.5%). These results indicate that Smith machine bench press training volume is not influenced by the grip width and that VLTs do not allow a more homogeneous prescription of the set volume with respect to the XRM than the traditional FNR.
... Exercise velocity is an important consideration when programming resistance training (21). Specifically, mean and peak velocity during training is commonly used to guide exercise prescription (9,10), mitigate or accentuate fatigue responses (6,25), enhance motivation and competitiveness (27,31), and monitor changes in physical performance (30,32,33). By monitoring velocity during resistance training, practitioners can accurately reproduce fatigue responses (22), while also closely controlling the kinetic and kinematic outputs that are produced (16,24). ...
... This accuracy during the back squat and bench press is important; it is advised that mean velocity is used to monitor performance because this variable has improved reliability when developing load-velocity profiles and has lower between-athlete variability in the velocity attained at 1RM (8,21). This suggests that the Perch can be used across a range of diverse monitoring and prescriptive methods including velocity loss thresholds (10,16,22) and 1RM estimation (5,7,9). ...
Article
This study aimed to assess the criterion validity and between-day reliability (accounting for technological and biological variability) of mean and peak concentric velocity from the Perch measurement system. On 2 testing occasions, 16 subjects completed repetitions at 20, 40, 60, 80, 90, and 100% of 1-repetition maximum in the free-weight barbell back squat and bench press. To assess criterion validity, values from the Perch and a 3-dimensional motion capture system (criterion) were compared. Technological variability was assessed by determining whether the differences between the Perch and criterion for each load were comparable for both testing sessions, whereas between-day reliability with both technological and biological variability was calculated from Perch values across days. Generalized estimating equations were used to calculate R 2 and root mean square error, whereas Bland-Altman plots assessed magnitude of difference between measures. To support monitoring of athletes over time, standard error of measurement and minimum detectable changes (MDC) were calculated. There was excellent agreement between the Perch and criterion device, with mean velocity in both exercises demonstrating a mean bias ranging from 20.01 to 0.01 m·s 21. For peak velocity, Perch underestimated velocity compared with the criterion ranging from 20.08 to 20.12 m·s 21 for the back squat and 20.01 to 20.02 m·s 21 for the bench press. Technological variability between-days were all less than the MDC. These findings demonstrate that the Perch provides valid and reliable mean and peak concentric velocity outputs across a range of velocities. Therefore, practitioners can confidently implement this device for the monitoring and prescription of resistance training.
... exists for the number of repetitions that can be completed before reaching different velocity loss thresholds (VLTs), 28 and several methodological factors could also influence the actual number of repetitions performed when using VLTs for prescribing the repetitions volume: the reference repetition used for calculating the VLT (first vs fastest), the velocity variable considered (MV vs mean propulsive velocity vs PV), and the criterion used for terminating a set (after one or more repetitions exceeded the VLT). 29 In this regard, another approach for prescribing the repetitions volume was proposed by García-Ramos et al, 9 who confirmed that lifting velocity can be used to predict the RTF during the Smith machine bench press exercise. The confirmation of these results in other exercises would enable the training prescription based on the XRM (ie, selecting a load and then deciding the number of repetitions to perform depending on the desired proximity to failure) without the need to frequently perform sets to failure during a training cycle. ...
... 27 The decrease in the ability to produce force (ie, fatigue) can be manifested by a decrease in both the RTF against a given load and the fastest repetition velocity of a set. 29 Therefore, in case the fatigue induced by performing multiple sets has different effects on the RTF and the fastest velocity of a set, it is plausible that the precision of the RTF-velocity relationships could be compromised. This study explored this issue for the first time and revealed that the execution of consecutive sets to failure separated by 2 minutes affected the RTF more than the fastest velocity of the set. ...
Objective: To explore (1) the goodness of fit of generalized and individualized relationships between the maximum number of repetitions performed to failure (RTF) and the fastest mean velocity and peak velocity of the sets (RTF-velocity relationships), (2) the between-sessions reliability of mean velocity and peak velocity values associated with different RTFs, and (3) whether the errors in the prediction of the RTF under fatigued and nonfatigued conditions differ between generalized and individualized RTF-velocity relationships. Methods: Twenty-three sport-science students performed 4 testing sessions with the prone bench pull exercise in a Smith machine: a 1-repetition-maximum [1RM] session, 2 identical sessions consisting of singles sets of RTF against 4 randomized loads (60%-70%-80%-90%1RM), and 1 session consisting of 4 sets of RTF against the 75%1RM. Results: Individualized RTF-velocity relationships presented a higher goodness of fit (r2 = .96-.97 vs .67-.70) and accuracy (absolute errors = 2.1-2.9 repetitions vs 2.8-4.3 repetitions) in the prediction of the RTF than generalized RTF-velocity relationships. The reliability of the velocity values associated with different RTFs was generally high (average within-subject coefficient of variation = 4.01% for mean velocity and 3.98% for peak velocity). The error in the prediction of the RTF increased by ~1 repetition under fatigue (ie, set 1 vs sets 2-4). Conclusions: Individualized RTF-velocity relationships can be used with acceptable precision and reliability to prescribe the loads associated with a given RTF during the match a specific XRM during the prone bench pull exercise, but a lower accuracy is expected in a fatigued state.
... In each set, two repetitions were performed. Research has shown that the fastest movement velocity (peak and mean) is achieved in the first two repetitions (García-Ramos et al., 2021). Furthermore it was chosen two repetitions to avoid the cumulative fatigue in the last loads. ...
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Jukic, I, García-Ramos, A, Malecek, J, Omcirk, D, and Tufano, JJ. Validity of load-velocity relationship to predict 1 repetition maximum during deadlifts performed with and without lifting straps: the accuracy of six prediction models. J Strength Cond Res XX(X): 000-000, 2020-This study aimed to compare the accuracy of six 1 repetition maximum (1RM) prediction models during deadlifts performed with (DLw) and without (DLn) lifting straps. In a counterbalanced order, 18 resistance-trained men performed 2 sessions that consisted of an incremental loading test (20-40-60-80-90% of 1RM) followed by 1RM attempts during the DLn (1RM = 162.0 ± 26.9 kg) and DLw (1RM = 179.0 ± 29.9 kg). Predicted 1RMs were calculated by entering both group and individualized mean concentric velocity of the 1RM (V1RM) into an individualized linear and polynomial regression equations, which were derived from the load-velocity relationship of 5 ([20-40-60-80-90% of 1RM], i.e., multiple-point method) or 2 ([40 and 90% of 1RM] i.e., 2-point method) incremental warm-up sets. The predicted 1RMs were deemed highly valid if the following criteria were met: trivial to small effect size, practically perfect r, and low absolute errors (<5 kg). The main findings revealed that although prediction models were more accurate during the DLn than DLw, none of the models provided an accurate estimation of the 1RM during both DLn (r = 0.92-0.98; absolute errors: 6.6-8.1 kg) and DLw (r = 0.80-0.93; absolute errors: 12.4-16.3 kg) according to our criteria. Therefore, these results suggest that the 1RM for both DLn and DLw should not be estimated through the recording of movement velocity if sport professionals are not willing to accept more than 5 kg of absolute errors.