Role of aerobic metabolism in sprint swimming Enhancing performance Dr Jamie Pringle; Dr Mike Peyrebrune English Institute of Sport, Loughborough

Physiological description Disproportional high volume of training Sprint v endurance trained Differences between individuals Fitness status Aerobic/efficiency interactions Examples from other sports Optimising warm-up Examples from the research Potential to enhance it? Long v short course differences

Sprinting Definition Olympic events 50m Free & 100m events Long Course vs. Short Course Duration - 22 to 26 s - 48 to 70 s Further adjustments for juniors & sub-elite level

Physiological description

Energy Metabolism

Considerably larger aerobic component than previously understood Review of 30+ studies Considerably larger aerobic component than previously understood AEROBIC % 12 27 37 45 51 56 63 73 79 ANAEROBIC % 88 73 63 55 49 44 37 27 21 From Gastin (2001). Energy System Interaction and Relative Contribution During Maximal Exercise. Sports. Med. 31:725-741

Differences between individuals

FASTER VO2 KINETICS DECREASES O2 DEFICIT Cardiac patient or very unfit Sedentary Endurance trained

High type I fibres High type II fibres Pringle et al (2003). Oxygen uptake kinetics during moderate, heavy and severe intensity ‘submaximal’ exercise in humans: the influence of muscle fibre type and capillarisation. Eur. J. Appl. Physiol., Vol. 89, pp. 289-290

Potential for enhancement?

Anaerobic work capacity (AWC) and oxygen use – all-out 60 s race 55% anaerobic 45% aerobic

The speed at which VO2 rises VO2 kinetics The speed at which VO2 rises

aerobic 110% VO2 max 100% VO2 max ~95% VO2 max 2:20 ± 0:06 min:s O2 deficit O2 deficit O2 deficit aerobic 2:20 ± 0:06 min:s 5:13 ± 0:50 min:s 9:48 ± 0:47 min:s Total O2 used: 6 L Total O2 used: 15 L Total O2 used: 31 L Total O2 required: 20 L Total O2 required: 29 L Total O2 required: 36 L O2 deficit: 14 L O2 deficit: 14 L O2 deficit: 15 L Carter, Pringle, Barstow, Doust (2006). Int. J. Sports Med., Vol. 27, pp. 149-157

Raises blood lactate – to 3 to 6 mM region Prior heavy exercise Raises blood lactate – to 3 to 6 mM region Muscle ‘vasodilatates’ – blood flow and oxygen delivery improved Subsequent exercise VO2 response is effectively ‘speeded’ – faster adaptation Repeated sprint recovery improved Burnley et al. (2001). Exp Physiol ;86; 417-425;

10 min 20 min 30 min 40 min 50 min Prior heavy exercise Effect lasts for ~30 min Lactate elevated for up to an hour Balance between recovery/restoration of AWC and residual effects of vasodilatation 10 min 20 min 30 min 40 min 50 min Burnley et al (2006). J. Appl. Physiol., Vol. 101, pp. 1320-1327

Differing types of warm-up Blood Blood No warm-up Moderate: 80% LT Heavy: 6 min at 50% D Sprint: 30 s all-out Wingate Fixed Self-paced 10 min 2 min 5 min 70% D All-out Burnley et al. (2005). Medicine & Science in Sports & Exercise. 37(5):838-845

1.0 mM B[La] 330 W 1.0 mM B[La] 338 W (+3%) 3.0 mM B[La] 339 W (+3%) No warm up 6 min easy paced 3.0 mM B[La] 339 W (+3%) 5.9 mM B[La] 324 W (-2%) 6 min ‘heavy’ 30 s all-out effort Burnley et al. (2005). Medicine & Science in Sports & Exercise. 37(5):838-845

Hunt J ,Brickley G, Dekerle J, Pringle J. Effect of prior heavy and severe intensity exercise on swimming performance in relation to critical speed and anaerobic distance capacity Hunt J ,Brickley G, Dekerle J, Pringle J. Hunt et al, (2009) (submitted)

MARKERS OR EXERCISE INTENSITY % VO2 Max 0 10 20 30 40 50 60 70 80 90 100 CP LT VO2 Max Moderate Heavy Severe Pi MUSCLE METABOLIC RESPONSES TO EXERCISE ABOVE AND BELOW THE ‘CRITICAL POWER’ 10% <CP 10% >CP [Pi] % Time (min) [PCr] % PCr Time (min) Time (min) pH pH Jones, Wilkerson, DiMenna, Fulford, Poole (2007). Am J Physiol Regulatory Integrative Comp Physiol, 294:585-593

EFFECT OF PRIOR EXERCISE Prior heavy intensity exercise enhances exercise tolerance (Carter et al, 2005) Residual acidemia (<5mM; Burnley et el, 2005)= Vasodilation Bohr shift in Oxyhaemoglobin dissociation curve = O2 delivery Elevated baseline VO2 (short recovery only) O2 Deficit VO2 slow component Prior Severe intensity exercise reduces exercise tolerance (Jones et al, 2003; Carter et al, 2005) Depletes anaerobic work capacity (Ferguson et a, 2007; Jones et al, 2007) Accumulation of fatigue related metabolites (H+, Pi, K+) (Jones at al, 2007) Ha = Prior heavy intensity exercise would improve performance whilst severe exercise would decrease performance in proportion to the (known) depletion of the anaerobic work (distance) capacity incurred in the prior exercise bout

PRIOR EXERCISE CONDITION PERFORMANCE TEST- SWIM TRIALS Methods Nine trained swimmers (4 female; age, 24 ± 2 years; mass 70 ± 4 kg) participated STAGE 1 STAGE 2 PRIOR EXERCISE CONDITION PERFORMANCE TEST- SWIM TRIALS PRE-TEST/ CONTOL 100m Free HEAVY 198 s at 95% of critical speed NO PRIOR EXERCISE 100m Free 400m Free 800m Free 800m Free 100m Free SEVERE 180 s at 105% of critical speed 800m Free Measures: Performance time without prior exercise-Derivation of the d v t relationship and estimation of CSS & ADC. Performance time for maximal effort swim trials –used to recalculate the CSS & ADC under prior exercise conditions Differences between conditions were tested using repeated measures ANOVA Relationships between data assessed using Pearson’s Product Moment Correlation

% worsening of performance time Results Measure  (Significantly different to control P < 0.05) Prior exercise Time (s) CSS (m.s-1) ADC (m) SR (cycles.min -1) SL (m.cycle-1)   100m 800m CONTOL 69.0 ± 3.1 672.2 ± 20.5 1.17 ± 0.03 20.1 ± 1.8 45.8 ± 1.5 33.2 ± 1.0 1.34 ± 0.04 1.82 ±0.05 HEAVY 70.0 ± 3.5 666.2 ± 22.0 1.18 ± 0.04 18.1 ± 1.8 42.1 ± 1.3 32.4 ± 0.8 1.46 ± 0.04 1.86 ±0.04 SEVERE 74.6 ± 3.5 670.1 ± 21.2 1.18 ± 0.03 12.7 ± 1.8 39.9 ± 1.6 32.9 ± 09 1.55 ± 0.06 1.83 ±0.05 Depletion of ADC (%) % worsening of performance time No ergogenic effect after HEAVY warm-up Uniqueness of performance protocol Anaerobic distance capacity was reduced by ~40% after SEVERE exercise The worsening in 100m trial performance after SEVERE prior exercise was significantly related to the reduction in ADC incurred (r = 0.72; P <0.05) 800 m performance requiring a large aerobic contribution was less affected by reduced anaerobic reserve Aerobic ~ 90%; Anaerobic ~10% i.e. 40% reduction in 10% 4% reduction in total work is not detectable in this protocol

Pringle and Defever (2008, in press) Pringle and Defever (2008, in press). Pre-exercise vasodilatation enhances total work production by increasing the aerobic contribution to ‘all-out’ cycle exercise and elevating the critical power Power ~7 to 10 % higher ~10 to 13% more O2 used ~7 to 10% more work achieved Significant beyond ~45 s

Pringle and Defever (2008, in press) Pringle and Defever (2008, in press). Pre-exercise vasodilatation enhances total work production by increasing the aerobic contribution to ‘all-out’ cycle exercise and elevating the critical power

Long v. short course

Short Course Total Time = 55 seconds The issue of SC (25 m) versus LC (50 m) in swimming training and preparation is a crucial one. The main issue involved is the pattern of energy metabolism between the 2 configurations. Swimming requires not only muscular contraction in the stroke movements themselves, but also starts and turns. The preparation for, execution of and the underwater phase after take up significant parts of the race. This can be used to the swimmer's benefit in that phases of starting and turning require different muscles to contract and therefore whilst the turning segment is performed, the stroke muscles are able to relax and recover.   Total Time = 55 seconds

Long Course Total Time = 56 seconds This obviously over-simplifies the complex interaction of muscle contraction, but generally, the strokes involve a high degree of upper body muscular contraction during the course of the length, whilst the turning phase requires more muscular contraction from the muscles of the lower body. Total Time = 56 seconds

Long Course vs. Short Course Total swim time increases from 33 s to 45 s Greater stress on aerobic energy sources 2. Swimming ~23 s sustained without a 'recovery‘ rather than 6-10 s approximately 3 times the duration without a break - not double. 3. Check Stroke Counts to illustrate: ~ 3 to 1

Economy and efficiency Maybe the real reason for high volume?

Training volume improves efficiency “I train around 35 hours a week which means I probably swim around 120 km over the seven days. I guess that is probably more than a lot of people drive! … I do two swimming sessions a day, seven days a week… it's very hard work and the early mornings are tough but I enjoy the challenge. “ Ian Thorpe, BBC Sport 2002

Efficiency Oxygen uptake Swimming speed

Coyle (2005) Improved muscular efficiency displayed as Tour de France champion matures J. Appl Physiol 98: 2191-2196

Relationship between training history and efficiency Metabolic component Skill component Improvements throughout a career Can compensate for lesser VO2 max

Physiological description Disproportional high volume of training Sprint v endurance trained Differences between individuals Fitness status Aerobic/efficiency interactions Examples from other sports Optimising warm-up Examples from the research Potential to enhance it? Long v short course differences