RESEARCH ARTICLE
Partial-body cryostimulation procured
performance and perceptual improvements
in amateur middle-distance runners
Massimo De Nardi1,2☯, Luca FilipasID3,4☯, Carlo Facheris1,3, Stefano RighettiID5,6,
Marco Tengattini5, Emanuela Faelli2,7, Ambra BisioID2,7, Gabriele Gallo2,7, Antonio La
Torre3,5,8, Piero Ruggeri2,7‡, Roberto CodellaID3,4‡*
1 Krioplanet Ltd, Treviglio, Bergamo, Italy, 2 Department of Experimental Medicine, Università degli Studi di
Genova, Genoa, Italy, 3 Department of Biomedical Sciences for Health, Università degli Studi di Milano,
Milan, Italy, 4 Department of Endocrinology, Nutrition and Metabolic Diseases, IRCCS MultiMedica, Milano,
Italy, 5 Italian Athletics Federation, Rome, Italy, 6 Interventional Cardiology Department, San Gerardo
Hospital, Monza, Italy, 7 Centro Polifunzionale di Scienze Motorie, Università degli Studi di Genova, Genoa,
Italy, 8 IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
☯ These authors contributed equally to this work.
‡ PR and RC also contributed equally to this work.
* roberto.codella@unimi.it
Abstract
The purpose of this study was to investigate the effects of partial-body cryostimulation on
middle-distance runners before two 3000-m tests at the speed of the first and second venti-
latory threshold, and before a time to exhaustion test at 110% of the maximal aerobic speed.
Twelve amateur runners (age: 46 ± 9 years; VO2max: 51.7 ± 4.9 mlkg-1min-1) completed six
running testing sessions in a randomized counterbalanced cross-over fashion: three of
them were preceded by a partial-body cryostimulation and the other three by a control condi-
tion. The testing sessions consisted of: 1) a 3000-m continuous running test at the speed of
the first ventilatory threshold; 2) a 3000-m continuous running test at the speed of the sec-
ond ventilatory threshold; 3) a time to exhaustion test at 110% of the maximal aerobic
speed. Heart rate, ratings of perceived exertion and visual analogue scale relative to muscle
pain were recorded throughout the tests. Total quality recovery was evaluated 24–48 h after
the end of each test. Distance to exhaustion was higher after partial-body cryostimulation
than control condition (p = 0.018; partial-body cryostimulation: 988 ± 332 m, control: 893 ±
311 m). There were differences in the ratings of perceived exertion during each split of the
3000-m continuous running test at the speed of the second ventilatory threshold (p = 0.001).
Partial-body cryostimulation can be positively considered to enhance middle-distance run-
ning performance and reduce perception of effort in amateur runners.
Introduction
In high-performance sport, coaches and sports scientists strive to identify novel interventions
to enhance performance maximizing the physical, psychological and behavioral state before a
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OPEN ACCESS
Citation: De Nardi M, Filipas L, Facheris C, Righetti
S, Tengattini M, Faelli E, et al. (2023) Partial-body
cryostimulation procured performance and
perceptual improvements in amateur middle-
distance runners. PLoS ONE 18(11): e0288700.
https://doi.org/10.1371/journal.pone.0288700
Editor: Nejka Potocnik, University of Ljubljana,
Medical faculty, SLOVENIA
Received: December 10, 2021
Accepted: July 3, 2023
Published: November 22, 2023
Copyright: © 2023 De Nardi et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Funding: The authors received no specific funding
for this work.
Competing interests: The authors have declared
that no competing interests exist.
competition [1, 2]. Prior to performance, several routines have been pursued with the aim of
enhancing oxygen uptake, cardiac output, blood flow to skeletal muscle, neuromuscular activa-
tion and mental readiness [3]. Running economy is certainly another typical target.
Pre-training typically involves a combination of passive and active elements which can
enhance exercise performance [4]. Active warm-ups are used to increase body temperature
leading to a higher muscle metabolism, enhanced oxygen uptake and subsequent cardiac out-
put [5], while passive warm up has the same goal but is mainly focused on various psychologi-
cal techniques or cooling/heating interventions [6]. Preparation through passive modalities is
becoming increasingly common for athlete management and performance enhancement [7].
Although every team, staff, strength and conditioning coach, have individualized methods and
preferences for their athletes/players, cutting-edge methodologies and techniques are evolving
and being available at large scale [8].
Cryotherapy is a relatively new clinical intervention used in different medical treatments to
alleviate pain derived from inflammatory conditions [9]. Given the extremely cold air temper-
atures of –110˚C or below, reached in short (1–4 min) exposures, cryostimulation can elicit
strong physiological responses in users [10], ranging from muscular soreness relief up to a
modest immunomodulatory effect [11].
The utilization of cryostimulation techniques before physical efforts is also known as pre-
cooling [12]. Usually, precooling aims to a rapid removal of heat of the body prior to exercising
in warm environments and to prevent the side effects of heat-stress-induced fatigue [13].
Reducing body temperature before commencing an effort has been found to be successful in
improving endurance performance both in hot and thermoneutral environments [14, 15].
Higher precooling effects were also observed in prolonged efforts [16], ambient temperature
and for aerobic capacity [17]. Improvements in endurance performance following precooling
interventions were achieved both with external (cold air exposure, water immersion, exposure
to ice, iced garments, iced towels, etc.), internal modalities (beverage ingestion, ice ingestion)
or combining two or more practical precooling methods [12, 17]. Cooling strategies are logisti-
cally challenging, therefore it is important to analyze the effectiveness of practical precooling
in competition or field setting [12].
In particular, the new transportable models of cryo-saunas have increased the diffusion of
partial-body cryostimulation (PBC) treatments before races and training [18], which have
been demonstrated to lower core and skin temperature for several hours [19]. Exposures to
very-low temperatures (approximately at -120˚C) could have positive impacts on core body
temperature, cardiovascular and autonomic functions [20], and perception of effort [21]. Nev-
ertheless, the disparities in the literature among various precooling methods, exercise efforts
and thermometry protocols remain substantial. This breath of knowledge could be scoped by
athletes, coaches and their extended entourage to tailor the maximizing-performance routine.
In this study, the effects of PBC on running performance were evaluated with two 3000-m
tests at the speed of the first and second ventilatory threshold, and before a time to exhaustion
test at 110% of the maximal aerobic speed (MAS). We aimed to test if PBC could be applied as
a prior to competition performance enhancement methodology in middle-distance events.
Our hypothesis was that running performance would have been improved by cryo-exposures,
along with lower value of perceptual fatigue.
Materials & methods
Experimental approach to the problem
A randomized counterbalanced cross-over design was used for the experimental component
of the present study. The order of the experimental treatments (PBC; control) and testing
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sessions were randomly allocated based on balanced permutations generated by a computer
program (www.randomization.com). A flow-chart of the protocol is offered in Fig 1.
Subjects
To determine an a priori sample-size (software package, G * Power 3.1.9.2), the following
input parameters were selected as per an F test for ANOVA-repeated measures-within factors
analysis: a statistical power (1-β) of 0.8, a significance α level of 0.05, an effect size f of 0.38
(which corresponds to a η2
p = 0.13), 1 group, 6 measurements, 0.5 as correlation among
repeated measurements. As output parameters, an actual power of 0.83, a critical F of 2.45
Fig 1. Flow-chart of the study.
https://doi.org/10.1371/journal.pone.0288700.g001
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were obtained. Therefore, eight subjects would have been sufficient to assess the sought effects.
However, to face a possible drop-out of one third of the subjects, thirteen male amateur run-
ners were recruited for this study. Participants were evaluated by a medical doctor who ascer-
tained their competitive suitability and excluded any contraindication to systemic
cryostimulation. Eligibility criteria were as follows: being free from any known medical dis-
eases, medication, injuries, color vision deficiencies. The study design and procedures were
approved by the local Ethics Committee and followed the ethical principles for medical
research involving human subjects set by the World Medical Association Declaration of Hel-
sinki. After ethical approval, written informed consent and medical declaration were obtained
from the participants in line with the procedures set by the local Institution’s Research Ethics
Committee. Subjects were informed of the procedures and potential risks involved, although
these were minimal as already described [22]. Participants were also informed that they could
withdraw from the study at any time, for any reason.
Procedures
Participants performed eight testing sessions on eight different occasions, in a period no lon-
ger than three weeks between the first and last visit (with at least 48 h between two visits). Vis-
its were carried in a private laboratory. All the experimental procedures were performed in an
isolated and air-conditioned room, at the constant temperature of 21 ± 1˚C and at a relative
humidity of 40–50%. Before each visit, participants were instructed to sleep for at least 8 h,
refrain from the consumption of alcohol and caffeine, and avoid any vigorous exercise for the
24-h preceding the testing sessions. Each participant carried out the visits individually and at
the same time of day (within 1 h period, between 7:30 and 10:30).
During visit 1, participants’ body weight and height were measured. Afterwards, they familiar-
ized with the procedures employed for the testing sessions, i.e. running on the treadmill used for
the study (Excite Treadmill, Technogym, Cesena, Italy) for at least 20 min wearing a portable gas
exchange system in breath-by-breath mode (Cosmed K5, Cosmed, Rome, Italy). Treadmill speed
was validated for each stage using an odometer (Stanley, Milano, Italy) to confirm that it was the
one declared by the manufacturer. During visit 2, participants completed an incremental exercise
test to determine their maximal oxygen uptake (VO2max). The test started with a standardized
warm-up consisting in 10 min of running at a constant speed of 10 kmh-1, followed by 5 min of
mobility drills. At the end of the mobility exercises, participants completed 10 min of passive
recovery and, after wearing the mask, 3 min in a standing position on the treadmill for the acquisi-
tion of basal values. After the warm-up, the incremental test started at a speed equal to 10 kmh-1,
with an increase of 0.1 kmh-1 every 12 s until exhaustion. Alveolar gas exchanges were measured
breath by breath in the mouth, eliminating any values outside the pre-established range, using a
specific software (OMNIA, Cosmed, Rome, Italy). Maximum oxygen uptake was calculated as the
30 s mean oxygen uptake once the plateau was reached. Runner’s VO2max was reached when at
least three of the following criteria were fulfilled: i) a steady state of VO2 (change in VO2 at
VO2max  150 mLmin-1), ii) final respiratory-exchange ratio (RER) exceeded 1.1, iii) visible
exhaustion, iv) a HR at the end of exercise within the 10 bpm of the predicted maximum, and v) a
lactate concentration at the end of exercise higher than 8 mmolL-1 [23]. Blood samples were
obtained immediately after exhaustion, in a single measurement, through the ear lobe, and were
analyzed for whole blood lactate using a portable lactate analyzer (Lactate Pro, Arcray Inc, Kyoto,
Japan), reported to have good reliability and accuracy [24]. First and second ventilatory thresholds
were detected through the ventilatory equivalents method [25] and the speeds associated were cal-
culated. In addition, researchers calculated the maximal aerobic speed (MAS) as the lowest run-
ning speed at which VO2max occurred.
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After the first two preliminary visits, participants carried out randomly the three testing ses-
sions, preceded either by a PBC or a control condition (six sessions in total, all randomized,
Fig 1). The testing sessions consisted of a 3000-m continuous running test at the speed of the
first ventilatory threshold, a 3000-m continuous running test at the speed of the second venti-
latory threshold and a time to exhaustion test at 110% of the MAS. The order of the tests and
the interventions were randomly counterbalanced. The tests were preceded by the same
warm-up routine described for the incremental ramp test. The warm-up started within two
minutes by the end of the PBC or control condition. The tests at the first and second ventila-
tory thresholds were performed over a distance of 3000 m to give enough time to the physio-
logical parameters to reach a steady-state.
Experimental treatments
Before each testing session, participants underwent either a PBC session or a control session.
During the PBC duty, participants completed the cryo-session (150 s) in a cryo-cabin (Space
Cabin, Criomed Ltd, Kherson, Ukraine). Temperature was set between -130 and -170˚C as
recommended [26]. Participants were instructed to turn around continuously (standing rota-
tions) in the cabin for the 150-second session. The control condition required to perform simi-
lar movement (standing rotations) for the same duration in a thermo neutral environment
(21 ± 1˚C). Immediately after the cryo-exposure or control task, the running tests were per-
formed. Due to the nature of the cryostimulation, participants were not blinded to their treat-
ments. However, the research team was blinded to the treatment because specific personnel
oversaw the treatments in a separated room.
Physiological and psychological measures
Heart rate (HR) was recorded, and averaged for the duration of the tests, using a HR monitor
fitted with a chest strap. VO2 was recorded using portable gas exchange system in breath-by-
breath mode (Cosmed K5, Cosmed, Rome, Italy) and data were averaged using the specific
software (OMNIA, Cosmed, Rome, Italy). During the 3000-m continuous running tests and
the 110% of the MAS test, VO2 were reported as the average of the last 30 s of the tests. Rating
of perceived exertion (RPE) was registered during the final 10 s of 1000- and 2000-m splits, at
the end of the 3000-m continuous running tests, and at the end of the time to exhaustion test.
RPE was measured with the 11-point CR10 scale developed by Borg [27]. Participants were
familiar with the scale as it had been employed during their daily training sessions for at least
six months ahead the tests. Participants recorded their subjective sensation of muscle pain by
using a visual analogue scale (VAS), before and after each test. Participants marked their
response on a 100-mm line anchored by 0 (no muscle pain at all) and 100 (maximum muscle
pain) [28]. The total quality recovery (TQR) scale [29] was used to monitor recovery. After 24
and 48 hours from the end of each test, participants answered the question “How do you feel
about your recovery?” using the TQR scale, in which answers are rated from 6 to 20.
Statistical analyses
All data are presented as mean ± standard deviation. Assumptions of statistical tests such as
normal distribution (Shapiro-Wilk test with visual inspection) and sphericity of data
(Mauchly’s test) were checked as appropriate. Greenhouse-Geisser correction to the degrees of
freedom was applied when violation to sphericity was present. Two-way repeated measured
ANOVA was used to determine the treatment factor (2 levels, PBC and Control), time factor
(3 levels, at 1000 m, 2000 m, 3000 m splits), and interaction on RPE during the 3000-m tests.
Significant main effects and interactions were interpreted through pairwise comparisons with
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Bonferroni correction. Paired sample t tests were used to compare the other variables between
the PBC and control conditions. Significance was set at 0.05 (two-tailed) for all analyses. Effect
sizes for repeated measure ANOVA are reported as partial eta squared (η2
p), using the small
(< 0.13), medium (0.13–0.25) and large (> 0.25) interpretation for effect size [30], while effect
sizes for pairwise comparison were calculated using Cohen’s d and considered to be either triv-
ial (effect size: < 0.20), small (0.21–0.60), moderate (0.61–1.20), large (1.21–2.00), or very large
(> 2.00) [31]. Data analysis was conducted using the Statistical Package for the Social Sciences,
version 25 (SPSS Inc., Chicago, IL, USA).
Results
Participants’ baseline characteristics and data derived from the incremental ramp test are
reported in Table 1. One participant was classified as outlier based on his maximum oxygen
uptake (VO2max) (more than two standard deviation from the mean of the sample) and
excluded from the analysis. Therefore, twelve subjects were included in the study procedures
(age: 46 ± 9 years; height: 1.75 ± 0.05 m; mass: 72 ± 8 kg).
Performance outcomes
Table 2 shows the performance outcomes derived from the 3000-m continuous running test at
the speed of the first and second ventilatory threshold and the time to exhaustion test at 110%
of the MAS. Running distance (p = 0.018, d = 0.30) and time (p = 0.020, d = 0.31) during the
time to exhaustion test were higher after PBC than control condition. No differences were
found among the other parameters.
Psychological outcomes
Table 3 shows the pairwise comparison of the psychological outcomes derived during the
3000-m continuous running test at the speed of the first and second ventilatory threshold and
the time to exhaustion test at 110% of the MAS. There was a significant condition x time inter-
action in the RPE during the 3000-m continuous running test at the speed of the second venti-
latory threshold (F (2,18) = 15.716, p = 0.001, η2
p = 0.43). Pairwise comparison revealed
significant differences for RPE in 1000-m (p = 0.010, d = 0.54), 2000-m (p = 0.030, d = 0.65)
Table 1. Participants’ characteristics at baseline (mean ± SD).
VO2max (mLkg-1min-1)
51.7 ± 4.9
HRmax, incremental test (bpm)
181 ± 16
vVT1 (kmh-1)
11.8 ± 0.9
vVT2 (kmh-1)
13.4 ± 0.9
MAS (kmh-1)
14.7 ± 1.1
VO2VT1 (mLkg-1min-1)
45.2 ± 5.3
VO2VT2 (mLkg-1min-1)
49.8 ± 5.3
HRVT1 (bpm)
156 ± 18
HRVT2 (bpm)
167 ± 17
VO2max: maximum oxygen uptake; HRmax: maximum heart rate; vVT1: velocity at first ventilatory threshold; vVT2:
velocity at second ventilatory threshold; MAS: maximum aerobic speed; VO2VT1: oxygen uptake at first ventilatory
threshold; VO2VT2: oxygen uptake at second ventilatory threshold; HRVT1: heart rate at first ventilatory threshold;
HRVT2: heart rate at second ventilatory threshold.
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Table 2. Performance outcomes from the three running tests in partial-body cryotherapy (PBC) and control conditions (mean ± SD).
3000-m test at VT1
PBC
Control
p
Cohen’s d
Time (s)
910 ± 77
919 ± 70
0.237
0.13
VO2 (mLkg-1min-1)
46.4 ± 5.5
47.1 ± 6.0
0.731
0.12
HR (bpm)
159 ± 17
159 ± 18
0.478
0.04
RER (VCO2VO2
-1)
0.84 ± 0.06
0.85 ± 0.05
0.750
0.13
3000-m test at VT2
Time (s)
693 ± 217
711 ± 152
0.491
0.09
VO2 (mLkg-1min-1)
48.8 ± 5.8
48.1 ± 5.2
0.502
0.13
HR (bpm)
168 ± 15
167 ± 17
0.625
0.05
RER (VCO2VO2
-1)
0.92 ± 0.08
0.92 ± 0.09
0.817
0.06
TTE at 110% of MAS
Distance (m)
988 ± 332
893 ± 311
0.018 *
0.30
Time (s)
222 ± 73
201 ± 67
0.020 *
0.31
VO2 (mLkg-1min-1)
49.8 ± 6.1
46.7 ± 6.2
0.233
0.49
HR (bpm)
170 ± 13
167 ± 13
0.227
0.21
RER (VCO2VO2
-1)
1.13 ± 0.11
1.13 ± 0.12
0.781
0.07
VT1: first ventilatory threshold; VT2: second ventilatory threshold; TTE: time to exhaustion; MAS: maximum aerobic speed; VO2: oxygen uptake; HR: heart rate; RER:
respiratory exchange ratio.
* Significant difference between the conditions (p < 0.05).
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Table 3. Psychological outcomes from the three running tests in partial-body cryotherapy (PBC) and control conditions (mean ± SD).
3000-m test at VT1
PBC
Control
p
Cohen’s d
VAS pre (mm)
11 ± 14
18 ± 16
0.151
0.44
VAS post (mm)
15 ± 18
17 ± 17
0.638
0.10
1000-m RPE
2.6 ± 1.2
2.3 ± 0.9
0.410
0.24
2000-m RPE
3.2 ± 1.5
3.0 ± 1.2
0.305
0.13
3000-m RPE
3.3 ± 1.9
3.3 ± 1.9
1.000
0.00
24-h TQR
17.5 ± 2.3
17.5 ± 2.6
0.915
0.02
48-h TQR
18.6 ± 2.1
18.1 ± 2.3
0.053
0.35
3000-m test at VT2
VAS pre (mm)
13 ± 11
11 ± 12
0.504
0.15
VAS post (mm)
13 ± 11
18 ± 17
0.141
0.41
1000-m RPE
3.2 ± 1.3
3.9 ± 1.5
0.010 *
0.54
2000-m RPE
4.3 ± 1.7
5.5 ± 2.1
0.030 *
0.65
3000-m RPE
5.3 ± 1.8
6.6 ± 2.7
0.008 *
0.56
24-h TQR
17.9 ± 2.1
16.3 ± 3.3
0.091
0.57
48-h TQR
18.2 ± 2.4
17.2 ± 2.4
0.090
0.44
TTE at 110% of MAS
VAS pre (mm)
8 ± 11
10 ± 14
0.748
0.14
VAS post (mm)
15 ± 14
23 ± 28
0.279
0.36
RPE at exhaustion
8.2 ± 2.0
8.3 ± 2.0
0.928
0.02
24-h TQR
17.2 ± 2.0
17.1 ± 2.1
0.903
0.04
48-h TQR
17.8 ± 1.8
17.3 ± 2.7
0.324
0.22
VT1: first ventilatory threshold; VT2: second ventilatory threshold; TTE: time to exhaustion; MAS: maximum aerobic speed; VAS: visual analogue scale; RPE: rating of
perceived exertion; TQR: total quality recovery.
* Significant difference between the conditions (p < 0.05).
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and 3000-m (p = 0.008, d = 0.56) splits. No differences were found among the other
parameters.
Discussion
The main finding of this study was that a PBC session increased running time to exhaustion,
showing an improved performance at 110% of MAS after a single PBC session compared to a
control condition. Further, RPE was significantly reduced after the PBC in each split of the
3000-m continuous running test at the second ventilatory threshold, suggesting that both cen-
tral and peripheral mechanisms could be affected by PBC. Partially unexpected, no other dif-
ferences were found in the two different conditions for other performance or psychological
measures.
This study showed a potential implication in adopting this relatively new technique before
running performance in a moderate-temperature condition. To date, an abundance of evi-
dence demonstrated the favorable use of PBC as a recovery modality after high intensity exer-
cise for athletes. Researchers have identified how PBC can improve recovery post-exercise by
maximizing anti-inflammatory and decreasing pro-inflammatory actions [9]. Conversely, to
the best of our knowledge, the effects of PBC before an exercise are mostly uncertain. Prior
investigations have documented the effectiveness of precooling using PBC in ameliorating
flexibility without losing the trunk position sense proprioception [32]. In addition, numerous
studies showed the positive influence of several precooling strategies in hot environments on
endurance performance, while no studies have evaluated the effects of PBC in thermoneutral
conditions [14]. Our results indicated PBC as a method capable to induce improvements in
middle-distance running performance, probably mediated by a lower RPE for the same exter-
nal workload. This is only a hypothesis as in the present study the improvement in perfor-
mance and the reduction of RPE occurred not in combination but during different tests. This
result is possibly due to the timing of the RPE evaluation, i.e. at the end of the time to exhaus-
tion test, and at each 1000-m split in the 3000-m time trials. Therefore, the ceiling effect of the
RPE in an exercise-to-exhaustion probably determined the lack of significance in the TTE at
110% of the MAS [27]. This result is not an unicum in the body of literature as a similar one
was found in a submaximal exercise in elite synchronized swimmers [33]. Klimek and col-
leagues have also shown an improvement in anaerobic capacity after 10 whole-body cryosti-
mulation sessions, principally explained by metabolic changes (i.e. increased activity of
anaerobic glycolytic enzymes) and a greater tolerance to pain, highlighted by an increase in
blood lactate concentration [34].
Reduction in pain could be easily linked to a decrease in perception of effort, a master regu-
lator of performance in endurance exercises [35]. Of note, perception of effort is determinant
in a TTE test, as it has been shown that maximum values of perception of effort lead to an
early stop to exercise, despite athletes could continue both muscularly and metabolically [36].
Physiologically, the reduction of perception of effort could be explained by the modification
of peripheral afferent signals generated by PBC, that could play a crucial role in changing the
perception of effort during exercise at low- and high-intensity [37]. In fact, together with neu-
ral drive from the motor cortex area, previous studies showed that RPE also is influenced by
afferent feedback from the periphery for the prediction of the endpoint of the exercise bout
[37, 38].
No other changes were observed in the other physiological and psychological parameters.
Our results are in line with previous studies that have shown no change in performance, recov-
ery, soreness perception parameters [39, 40], and with strategies that altered the perception of
effort [41, 42]. Moreover, the reduction of RPE at the same timepoints in the 3000-m tests
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implies that the RPE:VO2 and RPE:HR ratios are reduced in both tests in the PBC condition
compared to the control one. This reduction denotes an indirect change in the VO2 and HR
parameters, that would have been higher for the same RPE. This influence of PBC on RPE
indicates a strong impact of cryostimulation on fatigue, also shown by the lack of significance
shown by the VAS relative to muscle pain.
We must certainly highlight how the great variability of the measures is a factor to consider
in the interpretation of the results. It is known that the coefficient of variation of the TTE is
large. Despite constant-work test has a much lower coefficient of variation, with amateur ath-
letes we must also consider the variability generated by pacing behavior. Hinckson and Hop-
kins [43], using the relationship between exercise duration and power output showed that the
reliability of the equivalent mean power calculated from the constant-power test (0.6%) is even
better than from the constant-work test (1.0%). In addition, Laursen and colleagues [44]
reported that a small random variation in performance results in large variation in time to
exhaustion, which causes large value of coefficient of variation. On the other hand, the small
change after an intervention also leads to a large change in the time to exhaustion, therefore
the signal-to-noise ratio of the constant-power test should be comparable to the constant-work
test. In addition, participants were familiar with the experimental procedures, but especially in
the TTE, the nature of the performance was far from the performance habits of the
participants.
An important limitation of the present study is the lack of cardiovascular and physiological
measures that compared the effects of the exposure to the PBC itself. Defining cardiovascular
changes will be crucial for the assessment of the efficiency of PBC in sport.
Since the implementation of cryostimulation prior to competition is relatively recent [45],
there is a lack of comparability among methodologies, in terms of cryostimulation modalities,
exposure parameters, and types of exercise. Besides, future investigations should evaluate
whether the exercise-induced inflammatory response is preserved in warmer conditions, and
whether precooling effects are likewise effective with higher temperatures. Moreover, since we
included amateur master athletes, future studies should aim to verify if the results of the pres-
ent study could be extended to other population of athletes (e.g. young, elite, etc.). In addition,
the 48-h TQR values could indicate an inadequate recovery for participants who underwent
the subsequent visit after 48 h. However, most of them completed each visit with at least 72 h
of recovery in between.
Practical applications
This study results advocate for the use of cryostimulation before anerobic activities. Beyond
the recovery benefits reported in the literature, cryostimulation may boost performance in the
pre-execution phase. However, it is essential to evaluate the best timeframe to maximize the
potential enhancing-performance effects. Cryostimulation may be also reducing the percep-
tion of effort and this effect could be crucial for coaches to modulate the training prescription
of their athletes. Considering this result, athletes could potentially increase their external train-
ing load given the lower internal/perceptual load for the same external load. In fact, reducing
RPE for the same external load could lead to a higher number of repetitions during an interval
training session or a higher external intensity for each repetition.
Conclusions
A single PBC session may represent a favorable set-up routine before running, improving mid-
dle-distance running performance and reducing RPE for the same external effort also in mod-
erate-temperature conditions. Future studies should investigate the optimal integration of
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PBC with the traditional elements of active of pre-exercise routines, so to maximize middle-
distance performance.
Supporting information
S1 Data.
(XLSX)
Acknowledgments
The authors acknowledge support from the University of Milan through the APC initiative.
Author Contributions
Conceptualization: Massimo De Nardi, Luca Filipas, Carlo Facheris, Stefano Righetti, Marco
Tengattini, Emanuela Faelli, Ambra Bisio, Antonio La Torre, Piero Ruggeri, Roberto
Codella.
Data curation: Massimo De Nardi, Carlo Facheris, Stefano Righetti, Marco Tengattini.
Formal analysis: Massimo De Nardi, Carlo Facheris, Marco Tengattini.
Investigation: Massimo De Nardi, Carlo Facheris, Stefano Righetti, Marco Tengattini.
Methodology: Massimo De Nardi, Luca Filipas, Ambra Bisio, Roberto Codella.
Project administration: Massimo De Nardi, Luca Filipas, Emanuela Faelli, Gabriele Gallo,
Piero Ruggeri, Roberto Codella.
Supervision: Luca Filipas, Emanuela Faelli, Ambra Bisio, Antonio La Torre, Piero Ruggeri,
Roberto Codella.
Validation: Massimo De Nardi, Luca Filipas, Stefano Righetti, Gabriele Gallo, Antonio La
Torre, Piero Ruggeri, Roberto Codella.
Visualization: Massimo De Nardi, Luca Filipas, Marco Tengattini, Ambra Bisio, Gabriele
Gallo.
Writing – original draft: Massimo De Nardi, Luca Filipas, Carlo Facheris, Roberto Codella.
Writing – review & editing: Luca Filipas, Stefano Righetti, Emanuela Faelli, Ambra Bisio,
Gabriele Gallo, Antonio La Torre, Piero Ruggeri, Roberto Codella.
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Partial-body cryostimulation procured performance and perceptual improvements in amateur middle-distance runners.
De Nardi, Massimo,Filipas, Luca,Facheris, Carlo,Righetti, Stefano,Tengattini, Marco,Faelli, Emanuela,Bisio, Ambra,Gallo, Gabriele,La Torre, Antonio,Ruggeri, Piero,Codella, Roberto