Biomechanics and Medicine in Swimming XI

BiomechanicsandmedicineinswimmingXi
Training at Real and Simulated Altitude in
Swimming: Too High Expectations?
rodríguez, F.A.
Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona,
Spain
Altitude/hypoxic training is a common practice among swimmers although
scientific evidence is scarce and its benefits remain controversial.
While acute hypoxia deteriorates swimming performance, chronic hypoxia
may induce acclimatization effects which could improve aerobic
capacity and therewith performance upon return to sea level. Other potential
benefits such as improved exercise economy, enhanced muscle
buffer capacity and pH regulation, and improved mitochondrial function
have also been postulated. This paper aims to review current methods
of altitude/hypoxic training and to discuss the available scientific
evidence on the effects and potential benefits on sea-level swimming
performance.
Table 1. A summary of studies of altitude/hypoxic training with
swimmers
Table 1. A summary of studies of altitude/hypoxic training with swimmers
30
of controlled studies on AT in swimming and the evidence supporting
most approaches in athletes (Wilber, 2004), particularly in swimmers
(Truijens & Rodríguez, 2010), remains inconclusive. Moreover, field observations
and also research studies (Chapman et al., 1998) show that
AT may work for some athletes and not for others.
It has been estimated that an Olympic swimmer should improve
his or her performance by about 1% within the year leading up to the
Olympics to stay in contention for a medal (Pyne et al., 2004). A recent
meta-analysis concluded that the expectable performance benefit from
AT for elite athletes can be as high as 1.6% (Bonetti & Hopkins, 2009).
Perhaps a worthy strategy if a medal is just some tenths of a second away.
This paper aims to provide a brief, critical overview of peer-reviewed
scientific literature on AT for the improvement of swimming performance
at sea-level.
Is AltItude/hYPoXIc trAInInG Better thAn
trAInInG At seA leVel?
Table 1 presents a summary of AT studies from the international scientific
literature, with swimmers. In view of this table, the answer to the question
should likely be negative. However, the heterogeneity of research
designs, testing methods, performance level of subjects and performance
Key words: Altitude training, hypoxia, hypoxic training, intermittent
indicators make it difficult to derive sound conclusions based on the
hypoxia
limited evidence available. Most of our knowledge derives from studies
conducted in other sports such as long distance running, cycling, Nordic
IntroductIon
skiing and orienteering.
Altitude/hypoxic training (AT) plays an important role in preparing
swimmers Biomechanics all over and the Medicine world. Unfortunately, in Swimming XI there /Chapter is a 1 remarkable Invited Lectures lack
Page 46
Mode of hypoxia /
Strategy
Natural altitude
LH-TH
Natural altitude
LH-TH
Natural altitude
LH-TH
IHE hypobaric
Hi-Lo
IHE normobaric
Hi-Lo
IHE hypobaric
Hi-Lo
IHT normobaric
Lo-Hi
IHT hypobaric
Lo-Hi
Level /
Gender
College
M
Elite junior
M+F
Elite
M
Elite and
subelite
M+F
Elite
M+F
Trained
M+F
Trained
M+F
Trained
M
Control /
Design
No
Pre-post
No
Pre-post
No
Pre-post, same
group at two
altitudes
Yes
Pre-post,
matchedpaired
Yes
Pre-post, two
groups living
at 1200 m
Yes
Matchedpaired,
randomized,
double blind
Yes
Matchedpaired,
randomized,
double blind
Yes
Matchedpaired,
randomized
n
VO2max Altitude Duration Effect on
performance §
15 4.2 L/min 2300 m 2 wks ↔
at 200 and 500 yd TT
16 ? 2100-2300 m 3 wks ↑
Vmax and V4 (+2-3%*)
at incremental 5x100
or 5x400 m test
9 59 1850 vs 1200 m 13 d ↔
Vmax at 4x200 & 2000
m TT in 1850-m group
8/8 59 Rest at
≈4000-5500 m
9/9 58
at 1200 m
Sleep/rest 5 d at
≈2500 m and 8 d
at ≈3000 m vs
controls at 1200 m
6/7 55 Rest at
≈4000-5500 m
8/8 48-50 Training at
≈2500 m
6/6 56 Training at
≈1600-2400 m
3 h/d over 2
wks
13 d,
16 h/d
3 h/d,
5 d/wk over 4
wks
12.5 min of
high intensity
bouts added,
3x/wk over 5
wks
2 daily HT
sessions,
5 d/wk over 3
wks
↑
Vmax at 200 m TT
(0.9%*)
↔
Vmax at 5x200 m
and 2000 m TT
conducted at 1200 m
Only controls improved
↔
Vmax at 100 & 400 m
and incremental
swimming flume test in
both groups
↔
at 100 and 400 m TT
Both groups equally
improved
↔
at 100 and 200 m TT
Both groups equally
improved
Effect on VO2max § Other outcomes § References
↔ Faulkner et al.
(1967)
?
Not measured
↔
No changes in either
group
↑
VO2peak at 200-m TT
(+9.3%*) and at 400-m
TT (+5.4%*)
after 1-wk taper
↔
n.s.
(+4.5% in H group)
Both groups equally
improved
↑
at incremental
swimming flume test
(+7.5%*) after 2-wks
taper
↔
Both groups equally
improved
↔
Both groups equally
improved
↑ tHb-mass (+6.3%*) Friedmann et al.
(2005)
↑ Vmax at 2000 m TT
at 1200-m group only
↑ MCV and retics in
1850-m group only
↑ in [Hb], Htc, retics*
tHb-mass not measured
↑ tHb mass (+8.5%*)
↑ Vmax and TT 2000 m
in controls only* after
1-2 d, not after 15 d
↑ Ventilatory threshold
(+12.1%*)
↔ tHB-mass
↔ MAOD in both
groups
↑ MAOD in IHT group
(+29%) vs control
group (+14%)*
Roels et al.
(2006)
Rodríguez et al.
(2003)
Robach et al.
(2006)
Rodríguez et al.
(2007)
Truijens et al.
(2003)
Ogita & Tabata
(2003)
LH-TH: Living high-training high; LH-TL: Living high-training low; IHE: Intermittent hypoxic exposure at rest and/or sleep; IHT: Intermittent hypoxic training; M/F: male/female; TT: Time trial; MAOD: Maximal
accumulated oxygen deficit; H: hypoxia/altitude group; N: normoxia group; Vmax: maximal speed; V4: speed at 4 mmol/L lactate. § Added effect in the experimental group (controlled studies); ↑: Increase; ↔: No change;
*Significantly different from values measured before altitude/hypoxic training or compared to control group (p≤0.05); n.s.: non-significant difference (p>0.05).