half-time in team sports: an opportunity to influence subsequent performance?
TRANSCRIPT
Half-time in team sports: An opportunity to influence subsequent performance?
@drmarkru55ell
[email protected]/profile/Mark_Russell4
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Dr Mark RussellProgramme Leader MSc Strength and Conditioning, Northumbria University
National Lead for Applied Exercise Physiology, UK Deaf Sport
The primary purpose of half-time: A practitioners perspective
Red: Recovery after first half
Yellow: Preparation before second half
Blue: Transitional period between the two halves
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Towlson et al. (2013, JSS, 31, 1393-1401)
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Mohr et al. (2005; JSS, 23, 593-599)
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?
Mohr et al. (2005; JSS, 23, 593-599)
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Hawkins and Fuller (1996, BJSM, 30, 165-170)
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Lovell et al. (2013, SJMSS, 23, 105-113)
Temp 1°C
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Mohr et al. (2004, SJMSS, 14, 156-162)
1.1°C core temperature over half-time
correlated to a
2.4% in sprint performance
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Resting for the entire 15 min half-time interval in soccer is not an optimal preparation for the second half (Mohr et al., 2005)
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Half-time may provide an additional opportunity on the day of competition to benefit subsequent performance (Russell et al., 2014)
How can we improve body temperature
before the second half?
Barriers to rewarm-ups
Alternative methods of preserving body temperature may therefore be desirable
Towlson et al. (2013, JSS, 31, 1393-1401)
Passive heat maintenance seeks to maintain muscle and body temperature by attenuation of temperature losses typically by
specialised garments or heating methods.
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A passive heat maintenance strategy implemented during a simulated half-time improves lower body power output and repeated sprint ability in professional Rugby Union players
Russell et al. (2015, PLOS One)
Investigate the effects of wearing a survival jacket during a simulated half-time period in
professional Rugby Union players
Sta
rt/finis
h
20 m
Active timing gate Inactive timing gate
X2X1
X test administrator
A passive heat maintenance strategy implemented during a simulated half-time improves lower body power output and repeated sprint ability in professional Rugby Union players
Russell et al. (2015, PLOS One)
Repeated sprint test 1DowntimeWarm-up
First half
Half-time intervention Repeated sprint test 2
Seated in normal kit + survival jacket
Seated in normal kit
ControlPassive
Second half25 min 15 min
Russell et al. (2015, PLOS One)
A passive heat maintenance strategy implemented during a simulated half-time improves lower body power output and repeated sprint ability in professional Rugby Union players
Half-timeWarm-upWarm
-up Downtime First half Second half
-0.7%
-1.5%
-80%temp gained in warm-up
A passive heat maintenance strategy implemented during a simulated half-time improves lower body power output and repeated sprint ability in professional Rugby Union players
Russell et al. (2015, PLOS One)
Intervention
1.5%
A passive heat maintenance strategy implemented during a simulated half-time improves lower body power output and repeated sprint ability in professional Rugby Union players
Russell et al. (2015, PLOS One)
Start of second simulated half
End of first simulated half
Intervention
3.2%
Passive heat maintenance may be able to protect against losses of body temperature
typically observed over a half-time period and protect subsequent exercise performance.
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Hydro-nutritional strategies
• Between 6 and 10% carbohydrate containing drinks recommended before and during intermittent exercise
• Improve performance by delaying fatigue– Improving hydration status– Maintaining muscle glycogen stores– Increasing blood glucose concentrations
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Russell et al. (2012, JSAMS, 15, 348-354)
-30%
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6.0% CHO drink (CHO):
Kingsley et al. (2014, JSAMS, 17, 239-243)
-39%
-30%
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9.6% CHO–caffeine drink (H-CHO):
5.6% CHO drink (CHO):
57% of participants returned hypoglycaemic values (<3.80 mmol/L) at 60 min
*-40%
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6.0% CHO drink (CHO):
High vs. low glycaemic index carbohydrate?
Start End
First half W Second half
Soccer match simulation
+
X
Rest
X
ET1 ET2
PT PT
+++
PT PT PT
+
Warm-up
Cool down
Blood sample
Fluid-electrolyte consumption
X Mass measurement
Standardised meal PT Performance test Passive recovery
+ Treatment consumption
8 % PalatinoseTM (Low GI) vs. maltodextrin (High GI) electrolyte-containing beverages consumed before each half (~20 g h∙ -1
CHO)
Low glycaemic index carbohydrates, when consumed before each half of soccer-specific exercise may offer
an alternative strategy to high glycaemic index carbohydrate consumption due to more favourable
physiological responses and potential benefits to skilled performance
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Prof. Liam KilduffDr Mike Kingsley Prof. David Benton Prof. Christian Cook Tony Pennock
Liam Harper Dr Emma Stevenson Dr Anthony Watson Dr Dan West Gary Richards
Acknowledgements
Thanks for listening