Eleven Years' Monitoring of the World's Most Successful Male Biathlete of the Last Decade

Abstract

Purpose:
To report the changes in the training characteristics, performance, and heart-rate variability (HRV) of the world's most successful male biathlete of the last decade.

Method:
During the analyzed 11-year (2009-2019) period, the participant won 7 big crystal globes, corresponding to the winner of the International Biathlon Union World Cup. The training characteristics are reported as yearly volume (in hours) of low-intensity training (LIT), moderate- and high-intensity training, and speed and strength training. Performance was quantified by the number of World Cup top-3 positions per season. HRV was expressed as low- and high-frequency spectral power (in milliseconds squared), root-mean-square difference of successive R-R interval (in milliseconds), and heart rate (in beats per minute).

Results:
The training volume increased from 530 to ∼700 hours per year in 2009-2019, with a large polarization in training intensity distribution (ie, LIT 86.3% [2.9%]; moderate-intensity training 3.4% [1.5%]; high-intensity training 4.0% [0.7%]; strength 6.3% [1.6%]). The number of top-3 positions increased from 2 to 24-26 in 2009-2018 but decreased to 6 in 2019. The mean supine values in the root-mean-square difference of successive R-R interval and high-frequency spectral power divided by heart rate increased until 2015, which were stable over 2016-2018 but decreased in 2019. The number of top-3 positions was related to the total (r = .66, P = .02) and LIT (r = .92, P < .001) volume and to several markers of supine parasympathetic activity.

Conclusion:
The improvement in performance of the participant was mainly determined by the progressive increase in training volume, especially performed at low intensity, and was correlated to parasympathetic activity markers. This case study confirms the effectiveness of the training method, with a large amount of LIT in an elite endurance athlete, and of regular HRV monitoring.

Full text

Eleven Years’Monitoring of the World’s Most Successful Male
Biathlete of the Last Decade
Laurent Schmitt, Stéphane Bouthiaux, and Grégoire P. Millet
Purpose:To report the changes in the training characteristics, performance, and heart-rate variability (HRV) of the world’s
most successful male biathlete of the last decade. Method:During the analyzed 11-year (2009–2019) period, the participant
won 7 big crystal globes, corresponding to the winner of the International Biathlon Union World Cup. The training
characteristics are reported as yearly volume (in hours) of low-intensity training (LIT), moderate- and high-intensity
training, and speed and strength training. Performance was quantified by the number of World Cup top-3 positions per
season. HRV was expressed as low- and high-frequency spectral power (in milliseconds squared), root-mean-square
difference of successive R–R interval (in milliseconds), and heart rate (in beats per minute). Results:The training volume
increased from 530 to ∼700 hours per year in 2009–2019, with a large polarization in training intensity distribution (ie, LIT
86.3% [2.9%]; moderate-intensity training 3.4% [1.5%]; high-intensity training 4.0% [0.7%]; strength 6.3% [1.6%]). The
number of top-3 positions increased from 2 to 24–26 in 2009–2018 but decreased to 6 in 2019. The mean supine values in the
root-mean-square difference of successive R–R interval and high-frequency spectral power divided by heart rate increased
until 2015, which were stable over 2016–2018 but decreased in 2019. The number of top-3 positions was related to the total
(r= .66, P= .02) and LIT (r= .92, P<.001) volume and to several markers of supine parasympathetic activity. Conclusion:
The improvement in performance of the participant was mainly determined by the progressive increase in training volume,
especially performed at low intensity, and was correlated to parasympathetic activity markers. This case study confirms the
effectiveness of the training method, with a large amount of LIT in an elite endurance athlete, and of regular HRV
monitoring.
Keywords:biathlon, endurance performance, heart-rate variability, training intensity, training volume
For many years, the French Nordic-ski national teams period-
ized their training loads with the “polarized”principle.
1
This
method emphasizes the major influence of high training volume
performed at low intensity.
2–5
The “polarized”principle,
1
with a
“75-5-20”training intensity distribution across 3 intensity zones
(low-intensity training [LIT], moderate-intensity training [MIT],
and high-intensity training [HIT]), separated by the first and the
second lactate thresholds (LT1 and LT2), respectively, is preco-
nized in endurance disciplines.
6
For many years, the French
Nordic-ski national teams periodized their training loads with
even more than 75% of LIT. This method is in line with recent
studies that emphasized the major influence of high training
volume performed at low intensity.
2–5
Such distribution has
been observed in many endurance sports and is commonly used
by elite cross-country skiers.
1,5,7,8
Biathlon combines cross-country skiing and rifle shooting,
and requires considerable physiological demands, similar to those
associated with competitive cross-country skiing,
9,10
while also
requiring precise fine motor control for fast and accurate shooting
under mental pressure. World-class male biathletes demonstrate a
high maximal oxygen uptake of >80 mL·kg
−1
·min
−1
9
and perform
700 to 900 hours of physical training annually, including ∼80%
at LIT, 4% to 5% at MIT, 5% to 6% at HIT, and ∼10% of
strength and speed training.
10
This volume is slightly lower than
in cross-country skiers
8,11
due to the training time for shooting
(150–200 h).
8
It is known that the training components (intensity and
volume) influence heart-rate variability (HRV) responses, owing
to a modulation in autonomic nervous system activity.
12,13
Endur-
ance training stimulates the parasympathetic activity, represented
by the high-frequency spectral power (HF) and the root mean
square differences of successive R–R intervals (RMSSD) in
frequency and time domains, respectively. HIT stimulates the
sympathetic activity, mainly represented by the low-frequency
spectral power (LF). Training at LIT is therefore generally
believed to enhance parasympathetic autonomic activity
14,15
and
generally associated to a good state of health and fitness in
athletes. Moreover, our research group has previously reported
that HRV was related to training volume at LIT in elite Nordic-
skiers
1
and that the analysis of combined supine and standing
HRV spectral parameters led to the definition of 4 different
patterns of fatigue.
16
Case studies in world-class athletes are of high interest in
exercise physiology and provide unique data on their physiologi-
cal development and their training content.
7
However, to our
knowledge, there is no study reporting training characteristics and
HRV data over a long period (>10 y) in athletes of this perfor-
mance level. So, the aim of this study was to describe the overall
training, as well as the relationship between the development of
key load factors (volume and intensity distribution) in the training
and how these affect the heart variability and performance devel-
opment report of the world’s most successful male biathlete of the
last decade.
Schmitt is with the National Ski-Nordic Center, Premanon, France. Bouthiaux is
with the French Ski Federation, Annecy, France. Schmitt and Millet are with the Inst
of Sport Sciences, University of Lausanne, Lausanne, Switzerland. Schmitt (laurent.
schmitt@ensm.sports.gouv.fr) is corresponding author.
1
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Methods
Participant
The participant (born in 1988; aged 21–31 y; height 184 cm; weight
80 kg; VO
2
max 83 mL·mn
−1
·kg
−1
) is the most successful male
biathlete of the last decade. VO
2
max tests were performed in roller
ski at 1200 m of altitude in the French national training center of
Prémanon. He is the all-time biathlon record holder of overall
World Cup (WC) titles, with 7 big crystal globes in a row (2012–
2018), corresponding to the winner of the International Biathlon
Union WC. Over an 11-year period (2009–2019), he won 76 WC
events and 140 top-3 WC positions. He is a 5-time Olympic
champion (Sochi 2014, PyeongChang 2018).
Overall Design
The period studied was from the 2009 to 2019 season.
Training and Performance Characteristics
The training characteristics were extracted from his training log and
are reported as yearly volume (in hours) of LIT, MIT, HIT, and
speed and strength training. These intensity zones were defined
regularly from incremental tests performed by the French team
under the supervision of the same physiologist (L.S.) and are
separated by the LT1 and LT2. The LT1 corresponds to the first
increase in lactate above resting value and LT2 to the first break-
point of the lactate curve during an incremental test. Roller-ski tests
to measure VO
2
max and LTs were performed every year on road or
treadmill at 1200 m of altitude in June and October at the French
national training center of Prémanon.
The performance level was quantified by the number of WC
top-3 positions per season.
Moreover, the shooting performance was quantified as the
percentage of targets hit, extracted from the International Biathlon
Union database. We decided not to extract and analyze the skiing
performance per se, since it is affected by too many factors (snow
quality, altitude, equipment, waxing, tactical concerns, etc).
Heart-Rate Variability
The HRV tests were scheduled regularly during each year to record
HRV data at least twice during each 4-week mesocycle: 1 test during
the first 2 weeks and 1 at the end of the fourth week during the
recovery microcycle. No training session at an intensity equal to or
above the LT2 was performed 2 days preceding the HRV tests.
During the competition period, the tests were performed after 2 full
days of recovery (aerobic training), following the last competition.
The protocol has been previously described
1,16
: it was performed in
the same conditions at wake-up before breakfast, at rest in both the
supine and standing positions, and expressed as LF and HF (in
millisecond squared), RMSSD (in milliseconds), and heart rate (HR,
in beats per minute). During the competition period, the tests were
performed after 2 full days of recovery (aerobic training), following
the last competition. The head physiologist of the French national
Nordic ski teams (L.S.) was the sole investigator to analyze the data.
Statistical Analysis
All data from the 2009 to 2019 period are presented as mean (SD)
of each year. A 1-way analysis of variance was used to test the
statistical difference in the HR and HRV parameters between the
11 seasons. The Spearman rank-order correlation coefficient (r)
was used to analyze the relationship between season values
in performances, training characteristics, and HRV data. All
analyses were completed using SigmaStat (version 3.5; Systat
Software
®
, San Jose, CA). Statistical significance was accepted at
P<.05.
Results
Performance
For the entire studied period, the number of top-3 positions in WC
events increased from 2 to 24–26 in 2009–2018 but decreased to 6
in 2019 (Figure 1A).
Training volume increased from 530 to ∼700 hours per year in
2009–2019, with a large polarization in training intensity distribu-
tion (ie, LIT: 86.3% [2.9%]; MIT: 3.4% [1.5%]; HIT: 4.0% [0.7%];
strength: 6.3% [1.6%]; Figure 1B). MIT that ranged between 1.6%
and 3.6% from 2009 to 2018 was increased (7.4%) in 2019.
Figure 1C describes the training volume performed in the
different forms of training used year by year.
Two altitude training camps of 15 days at 1700 to 1850 m with
the living high-training high method were regularly performed in
August and November every year.
The shooting sessions were not quantified by their duration but
by the number of cartridges (ie, between 12,000 and 15,000) fired
every year. The specific shooting-only sessions were estimated at
∼30% of the number of cartridges fired per year.
The percentage of targets hit ranged between 85% in 2009 and
90.7% in 2017. The shooting performance was stabilized over the
last 3 seasons (90.7%, 90.2%, and 89.3% in 2017, 2018, and 2019,
respectively).
The shooting performance was correlated to the following
HRV parameters: HR in the supine (r=−.83, P<.001) and stand-
ing (r=−.79, P<.01) positions, as well as RMSSD (r= .72,
P<.01), LF (r= .73, P<.01), HF (r= .68, P<.05), and HF·HR
−1
(r=−0.73, P<.01) in the standing position.
The mean (SD) values of the HR and HRV parameters are
presented in Table 1.
The mean supine values in RMSSD (from 31 [12] to 114
[14] ms) and HF (from 817 [284] to 2910 [342] ms
2
) increased until
2015 and were stable over 2016–2018 but decreased in 2019 (94
[28] ms; 1815 [821] ms
2
). Similarly, the supine HR decreased from
44.4 [3.4] to 33.5 [1.7] bpm in 2018 but increased in 2019 (35.9
[1.8] bpm). The ratio of HF·HR
−1
measured in the supine position is
shown in Figure 1D. Over the period, the HRV parameters measured
in the standing position increased continuously (Table 1).
Three different periods were characterized in the 11 years
studied, as follows:
•From 2009 to 2013, the number of top-3 positions in WC events
increased gradually from 2 to 24. The annual training volume
increased regularly from 530 to ∼637 hours per year, with a
large polarization in training intensity distribution during this
period (ie, LIT: 88.5% [1.2%]; MIT: 2.5% [0.7%]; HIT: 3.9%
[0.4%]; strength: 5.1% [0.3%]). The mean supine values in
RMSSD (31 [12] to 90 [13] ms) and HF (817 [284] to 2234
[217] ms
2
) increased. Similarly, the supine HR decreased from
44.4 (3.4) to 37.3 (3.3) beats per minute.
•From 2014 to 2018, the number of top-3 positions in WC events
decreased in 2014 and 2015 (16 and 15) and increased again in
2016, 2017, and 2018 (19, 26, and 24, respectively). The annual
training volume was stabilized from 680 to 711 hours per year,
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with a polarization in training intensity distribution over the
period (ie, LIT: 85.5% [0.6%]; MIT: 3.5% [0.6%]; HIT: 4.2%
[1.0%]; strength: 6.8% [0.6%]). The mean supine values in
RMSSD increased from 91 [14] to 108 [16] milliseconds. The
HF decreased moderately from 2649 (297) to 2187 (588) milli-
seconds squared. Similarly, the supine HR decreased from 36.5
(3.3) to 33.5 (1.7) beats per minute.
•In 2019, performance showed an important decrease, with only
6 top-3 positions in WC events. The annual training volume
was similar to the 2 preceding seasons, with 691 hours per
year, but some changes were observed in the training intensity
distribution, with a decrease in LIT and increases in MIT and
strength training (ie, LIT: 79.1%; MIT: 7.4%; HIT: 3.4%;
strength: 10%). When compared with the previous season, the
Figure 1 —From season 2009 to 2019: (A) number of top-3 positions in International Biathlon Union World Cup events (first, second, and third
positions). (B) Training volume and intensity distribution: I, LIT (below first lactate threshold); II, MIT (between first and second lactate thresholds);
III, HIT (above second lactate threshold); and IV, speed and strength training. (C) Training volume in the different forms of activity (roller-ski, ski,
running, cycling, strength, and various). (D) HF (in milliseconds squared) divided by HR (in beats per minute); HF·HR
−1
(in normalized units [n.u.]).
HF indicates high-frequency spectral power; HIT, high-intensity training; HR, heart rate; LIT, low-intensity training; MIT, moderate-intensity
training.
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mean supine values in RMSSD and HF decreased, while the
supine HR increased.
Relationships Between Performances, Training
Characteristics, and HRV Parameters
The number of top-3 positions per season was related to the yearly
total (r= .73, P= .009) and LIT (r= .92, P<.001; Figure 2A)
volume and to several markers of supine parasympathetic activity
as HF·HR
−1
(r= .57, P= .05; Figure 2B), HR (r=−.66, P= .02;
Figure 2C), and RMSSD (r= .58, P= .05; Figure 2D).
Shooting performance was correlated to the following HRV
parameters of the studied period: HR in the supine (r=−.83,
P<.001) and standing (r=−.79, P<.01) positions, as well as
RMSSD (r= .72, P<.01), LF (r= .73, P<.01), HF (r= .68, P<.05),
and HF·HR
−1
(r=−.73, P<.01) in the standing position.
Discussion
This study reports the changes in training volume in the most
successful male biathlete of the last decade, with a progressive
increase from 530 to ∼700 hours between 2009 and 2016 and a
plateau over the last 3 years. This training volume is lower than that
for a world-class cross-country skier (750–900 h).
5
The total
training volume analyzed in this case study does not take into
account the specific shooting sessions, which represent ∼30% of
the number of cartridges fired per year. From 2009 to 2018, the
intensity distribution remained quite similar across the seasons,
Figure 2 —Correlations between the number of top-3 positions per season over the 11-year period (2009–2019). (A) The volume at LIT below first
lactate threshold, (B) resting supine mean yearly values in HF·HR
−1
(in normalized units [n.u.]), (C) resting supine mean yearly values in HR (in beats per
minute), and (D) resting supine mean yearly values in RMSSD (in milliseconds). HF·HR
−1
indicates high-frequency spectral power divided by heart rate;
HR, heart rate; LIT, low-intensity training; RMSSD, root-mean-square differences of successive R–R intervals.
Table 1 Yearly Mean Values of HR-Variability Parameters Measured at Rest in Supine and Standing Positions
Supine Standing
Season HR, bpm RMSSD, ms LF, ms
2
HF, ms
2
HR, bpm RMSSD, ms LF, ms
2
HF, ms
2
2009 44.4 (3.4) 31 (12) 1118 (275) 817 (284) 59.4 (4.6) 30 (11) 2439 (763) 281 (148)
2010 44.0 (3.1) 44 (13) 1083 (276) 1279 (298) 58.5 (4.1) 31 (11) 2611 (849) 297 (143)
2011 40.3 (3.3)** 51 (13) 2189 (417) 1485 (312) 57.7 (3.0) 34 (13) 2824 (1004) 356 (186)
2012 39.0 (3.3) 95 (13)** 2472 (391) 2412 (260) 58.1 (3.3) 34 (13) 2634 (1124) 335 (200)
2013 37.3 (3.3) 89 (13) 3421 (334) 2234 (217) 58.7 (2.3)*** 31 (11)* 2559 (1069) 307 (170)*
2014 36.5 (3.3) 91 (14) 3337 (326) 2649 (297) 59.0 (1.9)** 32 (11) 2741 (1265) 330 (175)
2015 34.6 (3.3)* 114 (14) 3653 (367) 2910 (342) 58.6 (2.0) 34 (11) 3011 (1274) 337 (177)
2016 34.9 (2.2) 99 (15)* 1841 (495)*** 2007 (418)** 58.8 (1.9) 35 (10) 3177 (1212)* 352 (172)**
2017 34.2 (1.6) 99 (17) 2211 (495) 2137 (455) 58.1 (2.1) 39 (11) 3670 (1237) 394 (155)
2018 33.5 (1.7) 108 (19) 1992 (497) 2187 (588) 58.4 (2.6) 40 (10) 3603 (1293) 398 (152)
2019 35.9 (1.8)** 94 (28) 1961 (489) 1815 (821)* 59.5 (3.8) 39 (11) 3346 (1496) 385 (164)
ANOVA,P *** *** ** ** *** *** ***
Abbreviations: ANOVA, analysis of variance; bpm, beats·min
–1
; HF, high-frequency spectral power; HR, heart rate; LF, low-frequency spectral power; RMSSD, root-
mean-square differences of successive R–R interval.
*P<.05, **P<.01, ***P<.001 for difference with previous season.
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with 87.0% (1.8%) at LIT. This large amount of LIT is higher than
the 75% usually associated to the “polarized training”paradigm
6
but is in line with previous reports in cross-country skiers.
5,7,8
The
correlation between his performance level and the total training
volume, as well as the LIT volume, emphasizes the need for a large
amount of aerobic training, not only during the early phase of the
career in an endurance athlete but also even when he has achieved
the highest level.
The improvement in shooting performance over the studied
period was related to a decrease in HR in both the supine and
standing positions, as well as an increase in the HRV parameters. It
may come from either direct (ie, improved HR recovery and larger
tachycardia facilitating the shooting when HF is higher) or indirect
(ie, lower fatigue and/or higher confidence in shooting when his
physical fitness was high, as associated with the HRV parameters)
mechanisms.
Of high interest is the change observed in 2019, when the
participant modified the training distribution by increasing the
volume in MIT and decreasing the volume carried out in LIT.
These changes in his intensity distribution were concomitant with a
clear decrease in performance, although the training volume re-
mained similar to the 3 previous years.
The HRV data also followed several phases over the period:
from 2009 to 2015, the markers of the temporal (RMSSD) and
spectral (LF, HF, LF + HF, and LF·HR
−1
) parasympathetic activi-
ties when measured in the supine position were regularly increas-
ing. Then, there was a plateau, followed by a regression in the 2019
season, when these supine HRV parameters went back to the values
measured in 2011–2014.
The standing HRV parameters did not display a similar trend
and increased nonlinearly but continuously over the 11-year period.
Overall, the respective changes in the supine (mainly HF and
RMSSD, parasympathetic activity) andstanding (LF, predominantly
sympathetic activity) positions support the assumptions that (1) both
the supine and standing measurements of HRV are valuable and
(2) elite endurance performance requires a high level of both
parasympathetic and sympathetic activities. However, the relation-
ship between performance and HRV (especially HF, HF·HR
−1
,and
RMSSD) appears to be stronger with markers of parasympathetic
activity that is enhanced mainly by LIT.
Practical Applications
One important contribution of this study is that the annual perfor-
mance development appears to be closely related to the training
being “polarized,”with an annual increase in the load in the form of
an increased number of hours at low intensity.
Most of the supine and standing HRV parameters increased or
remained very high over the period, except in 2019, which
corresponded to a training “less polarized”and a decreased per-
formance level. Overall, this case study confirms the effectiveness
of a training method with a large amount of LIT in an elite
endurance athlete. Moreover, it demonstrates the benefits of regular
HRV monitoring.
Conclusion
The improvement in performance in the most successful male
biathlete over the last decade is obviously the consequence of many
factors. One of the most important factors appears to be the
progressive increase in training volume, especially performed at
low intensity. Since HRV and HR are correlated to the variation in
performance, regular monitoring including these parameters ap-
pears to be effective. This case study confirms the effectiveness of a
training method with a large amount of LIT in an elite endurance
athlete and HRV monitoring in both the supine and standing
positions.
Acknowledgment
The authors warmly acknowledge Martin Fourcade for openly sharing his
training and HRV data.
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