Exercise Physiology Lab Protocols

How can a wingate test be used to improve speed endurance?

Repeated sprints = power decline (esp. with suboptimal recovery).

What adaptations occur as result of wingate test endurance training?

Allows increase in muscle glycogen stores, muscle acid tolerance and removal and increased buffering (tolerance of H ions) which leads to faster glycolysis.

What % aerobic contributions makes up a wingate test?

16%

What % anaerobic contributions makes up a wingate test?

56%

What % ATP-PCr contributions makes up a wingate test?

28%

What energy systems are used for speed events?

ATP (6.3%), PCr (49.6%)& Anaerobic Glycolysis (44.1%). Speed events tend to be short and powerful, rather than endurance based. This means they use anaerobic systems – short-term high intensity activity fuelled by glycogen without oxygen. Adenylate Kinase & Myokinase

Should endurance trained athletes use SET (speed endurance training)?

Yes, allows adaptations at muscle and cellular level. Also allows quicker/greater recovery.

Improves: running economy, VO2 max, endurance performance, lactate threshold.

Why would a predominant energy system not be the aerobic system during a wingate test?

What does RER represent and what does it tell us?

Indirect calorimetry measures the rate of CO2 release (V̇CO2)and oxygen consumption (V̇O2). The ratio between these two values is termed the respiratory exchange ratio (RER).

What is the calculation for RER?

RER = V̇CO2/ V̇O2

What do values of RER mean?

During exercise, though, muscles rely increasingly on carbohydrate for energy, resulting in a higher RER. As exercise intensity increases, the muscles’ carbohydrate demand also increases. As more carbohydrate is used, the RER value approaches 1.0.

What muscle fibres are mainly used in speed based events?

Fast fatigable T2. Predominantly type two muscle fibres used, enhancing motor neuron ring frequency & conduction velocity. Type 2a fibres have high glycolytic capacity and fast contractile speed. They also have larger CSA, more anaerobic enzymes, SR calcium stores & faster nerve conduction.

Explain the lactate shuttle?

Allows for glycolysis in one cell to supply fuel for use by another cell. During exercise, approximately 80% to 90% of lactate is transferred across the sarcolemma either by passive diffusion or by facilitated transport through MCTs (monocarboxylate transport)

Why can flexibility reduce?

• muscle growth

• age - breakdown/degradation of muscle

• injury

• posture

• daily living activity

What is static flexibility?

total range a joint/muscle can achieve with not speed focus

What is dynamic flexibility?

range of motion a joint/muscle can achieve in motion

What are the two main training methods for flexibility?

range of motion exercises, stretching exercises (unassisted and assisted)

What do range of motion exercises target?

work within limits of tissue, focuses on maintenance of current levels

What do stretching exercises target?

soft tissue structures beyond their available length, increase ROM

What are examples of unassisted stretching?

static, dynamic/ballistic, isometric

What are examples of assisted stretching?

passive, PNF ((Proprioceptive Neuromuscular facilitation) – neural system manipulation providing biggest gains via improved stretch tolerance, manipulation of muscle with minimal effort)

What is lactate threshold?

VO2 where lactate begins accumulating, indicating near fatigue of ATP generation, cannot be sustained for prolonged periods of time

Why can lactate testing be useful?

determines maximum potential of athlete, setting the upper limit for energy production

What can improved exercise economy provide?

O2 uptake required at a given absolute exercise training intensity = endurance trained individuals are more economical than lesser trained & speed increases at same performance VO2

What is the relationship between glycogen and intensity?

High muscle glycogen depletion during endurance exercise, intensity dependant (higher = faster depletion)

What can endurance training provide?

improves VO2max, lactate threshold, performance VO2, & exercise economy (central & peripheral) = higher sustained race pace

What is a cortex resting sample?

A gas analysis measuring breath-by-breath oxygen uptake (VO2), CO2 production (VCO2) and ventilation (Ve)

Why does blood lactate increase after a single 30s sprint?

Short duration, high intensity = heavy reliance on anaerobic pathways

• aerobic system (req. oxygen) = too slow to meet demand initially.

Glucose → Pyruvate → Lactate (via LDH)

What happens to peak power during a wingate protocol? Why does this decrease over time?

slow decline of peak power and power output

Where is lactate produced?

lactate is primarily produced in the cytoplasm of muscle cells—specifically in skeletal muscle fibers—during anaerobic glycolysis

Briefly explain the lactate shuttle hypothesis?

Isotope tracer studies show that lactate produced in fast-twitch muscle fibers (and other tissues) circulates to other fast-twitch or slow-twitch fibers for conversion to pyruvate. Pyruvate, in turn, converts to acetyl-CoA and enters into the citric acid cycle (see the next section) for aerobic energy metabolism. This process of lactate shuttling among cells enables glycogenolysis in one cell to supply other cells with fuel for oxidation.

What is meant by buffering capacity with regard to speed endurance?

Key buffering systems = bicarbonate (HCO3-) & proteins that can absorb excess H+ ions

• lactate = temporary storage for H+ ions helping to stabilise pH until cleared

How is buffering capacity increased through speed endurance training?

Increased tolerance of H+ ions via (carnosine, sodium phosphate, bicarbonate). increased activity of glycolytic enzymes (PFK,PDH) allowing greater buffering of H+ and faster glycolysis.

What is a mid-thigh pull procedure?

multi-joint exercise designed to assess the strength and force production capabilities of an athlete’s entire body

What can the mid-thigh pull (IMTP) show?

correlate with performance variables such as vertical jump and sprint speed

What is the format of an IMTP?

requires an individual to pull on a fixed barbell with a maximal effort for 3-5 seconds

• on top of a force plate → peak force, relative force, rate of force development (RFD), time to peak force

Why can the IMTP be advantageous for S&C coaches?

non-compromising positions, 1RM tests can cause disruptions or breaks in technique, multiple athletes can be assessed due to short length of test, mirrors positioning of the second pull in the clean & jerk weightlifting movement

What does the knee moving towards the midline mean in flexibility testing?

What does tightness in the hip present in FABER testing?

pain in the hip

What shows tight muscles surrounding the thigh in FABER test?

pain in lateral thigh

What does pain at the bottom of the back mean in FABER testing?

tightness in the sacroiliac joint

How should the knee align in FABER test?

bent knee should fall below or inline with the straight knee

What if the knee doesn’t drop below the other knee in FABER test?

less movement around the hip/SIJ area → ask questions to determine where the pain is (hip, thigh or lower back?)

How does lumbar lordosis present in the modified thomas test?

tight hip flexors

What does inability to bring hip into full extension mean in modified thomas test?

hip flexor tightness

What does inability to bring knee into 90* extension mean in modified thomas test?

quadricep tightness

What happens if the knee drifts away from midline in modified thomas test whilst participant is lying on their back?

lateral thigh tightness

What does flexibility mean?

The ability to move a joint or a series of joints smoothly and easily through an unrestricted, pain-free range of motion (ROM)

What are methods of measuring flexibility?

• goniometer

• positional (sit and reach/functional tests)

What is PNF stretching?

Proprioceptive Neuromuscular facilitation

▸ Manipulation of neural system. provides biggest gains!

▸ Improves tolerance to stretch

What role do golgi tendon organs provide in flexibility?

Contraction sensitive mechanoreceptors

What do muscle stretch receptors dictate?

speed at which the lengthening of tissue sheath occurs

Why is it suggested to use lifting straps in a maximum effort IMTP?

grip strength can be a limiting factor in overall strength

Why should the participant stand still during the weighing period?

leaning (shown by higher force on one side leg) or movement can affect the overall BM calculation

What should we consider in terms of footwear when performing an IMTP?

excess cushioning can inhibit force transfer to plates, flat sole helps to balance centre of mass

What is the difference between ‘peak force’ and ‘net peak force’ in an IMTP and why would we calculate both?

peak force = total force, net peak force = adjusted for gravity & bodyweight

What should we consider in terms of an individual’s suitability for performing a maximal IMTP?

injury history, familiarity with test procedure, age, warm-up, medical conditions

What should you remind the participant of during an IMTP?

maintaining neutral spine, shoulders behind the bar, pushing force through their feet