Pure Science

/posts/tayganrobson_adaptation-does-not-happen-during-training-share-7443601318302097408-1Hw0?utm_source=share&utm_medium=member_ios&rcm=ACoAACllOhkBXCsofJ75e99EL0KHPWZsrDDCL74 #trainingadaptation #periodisation

Brain glucose, muscle glycogen, and carbohydrate (CHO) efficiency in athletes: An evidence-based review. CLAIM: “The Real Performance Driver Is Brain Glucose.” REALITY: While brain glycogen does contribute to central fatigue, this can be combined with muscle glycogen depletion to limit performance. Both mechanisms work in conjunction with one another and do not act independently. CLAIM: “CHO Loading Does Not Improve Performance.” REALITY: Multiple meta-analysis studies have demonstrated that proper CHO intake prior to competition results in an improvement of 2-7.5 % in time trials, and an improvement of 15-54 % in time to exhaustion. The amount of CHO consumed during these types of competitions should range from 30-90 grams per hour during the activity. CLAIM: “High CHO Diets Reduce Metabolic Efficiency.” REALITY: Training in a strategic low CHO diet may increase the rate at which an athlete can oxidise fats, however, there has been no significant difference in overall athletic performance when compared to traditional CHO based training methods. CHO remain the most efficient source of fuel for high-intensity activities. CLAIM: “Endurance Training Causes Insulin Resistance When Consumed On A High CHO Diet.” REALITY: Conversely, endurance training increases the sensitivity of the body to insulin, allows glucose to enter cells easier, and improves the body’s ability to use different substrates for energy. EVIDENCE-BASED RECOMMENDATIONS Pre-competition CHO load of 5-12 grams per kilogram of body weight for events lasting longer than 90 minutes. During competition CHO intake of 30-90 grams per hour depending on, athlete gender, weight, the intensity and duration of the event. Use a combination of CHO such as glucose and fructose to optimise CHO absorption rates. Reference: Temesi, J. et al. (2011). Carbohydrate ingestion during endurance exercise improves performance in adults. The Journal of Nutrition. 141(5), pp. 890–897. doi:10.3945/jn.110.137075.

The Beetroot Phenomenon in Sports Performance Foundational Science: Larsen et al. (2007) first showed dietary nitrate reduces oxygen cost at sub-maximal levels. Lundberg, Weitzberg and Gladwin (2008) identified the nitrate-nitrite-nitric oxide pathway, whereby dietary nitrate act independently of nitric oxide synthase, enhancing blood vessel function during hypoxia. Jones et al. (2009) showed 500ml beetroot juice daily for six days lowers oxygen consumption and delays time to exhaustion. Mechanism: conversion of nitrate to nitrite by oral bacteria, and then to nitric oxide in working. Effects on Performance: • Acute dosing: performance improved 1-3% with 500ml (6-8mmol nitrate) consumed 2-3 hours before exercise. • Optimal duration: moderate intensity effort 4-30 minutes where oxygen delivery limits performance. • Timing rationale: Nitrite peaks 2-2.5 hours post consumption. Insights: Lundberg, Weitzberg and Gladwin (2008) report anti-bacterial rinses destroy bacteria blocking conversion from nitrate to nitrite. Elite athletes show reduced response to nitrate - highly trained athletes show less performance improvement (or none) than recreational athletes - suggesting potential ceiling effects on mitochondria’s capacity to transport energy within our bodies (Jones, 2014). History turned on its head - before 2007 nitrate considered harmful when consumed. Beetroot emerged unlikely as an ergogenic aid backed by verifiable research in sports supplements dominated by dubious unsubstantiated claims. Individual responses: Jones et al. (2013) report oral microbiome, degree of pre-exercise training status, baseline nitrate intake varies greatly, making for problematic testing, with the extent and scope of the effect means that some athletes don’t respond. The reality: The industry capitalised on beetroot’s rare combination of legal status, natural source credibility, and reproducible research findings. Concentrated shots emerged as practical alternatives to consuming large juice volumes pre-competition. Evidence shows chronic supplementation, provides no additional benefit beyond acute dosing (Jones, 2014). #Beetroot

Weekend riding when sick: Low-Intensity steady-state (LISS) during Cortisol Spike Restrict your training to LISS when you are feeling sick or under high physiological stress: <60-70% HRmax, <2mmol/L lactate, or <3/10 on the RPE scale. Good examples of this would be 60-90 minute zone 2 cycling, Steady pace swimming, or paced walking. 1. Immune Response & Recovery Debt High-intensity exercise suppresses immune function for 12-72 hours post-exercise due to increased levels of cortisol and inflammatory cytokines (IL-6 and TNF-α). Delaying clearance and increasing relapse risk (Nieman, 1994). Fever and poor quality sleep, indicate accumulate physiological stress. LISS provides aerobic stimulus without impairing your immune system or worsen recovery debt. 2. Autonomic Nervous System Balance Resting heart rate >10% above baseline your indicates sympathetic nervous system dominance (fight or flight).High-intensity training further shifts HRV toward sympathetic dominance, delaying parasympathetic recovery(rest-and-digest) necessary for healing and metabolic restoration (Meeusen et al., 2013). LISS promotes parasympathetic activation without additional autonomic strain. 3. Mitochondrial Efficiency Without Excessive Metabolic Stress Illness depletes muscle glycogen stores by 30-40%. LISS maximise utilisation of fat oxidation and mitochondrial biogenesis while avoiding excessive lactate production. Combining high-intensity training with the systemic inflammation risks overtraining syndrome. 4. Cardiac Drift Management Elevated baseline heart rate increases cardiac drift risk during intensity. A progressive HR increase at continuous power output suggesting cardiovascular strain. LISS maintains manageable cardiac demand during compromised physiological states. #Endurance #cycling #weekend #rides

Single-Leg Barbell Glute Thruster (Off-Bench Variation)  🎯 Target Muscles: • Primary: Gluteus Maximus, Hamstrings 🦵 • Secondary: Core (anti-rotation) 💪, Hip Stabilizers ⚖️, Quadriceps 🦿 1. Positioning: • Sit on the floor with upper back against the side of a bench (perpendicular) 🪑 • Roll a loaded barbell over hips (use pad or towel) 🏋️ • Extend one leg straight (working leg) ➡️, other foot flat on floor (support leg) 🦶 2. Starting Position: • Drive through supporting foot to lift hips until body forms a straight line from shoulders to knee ➖ • Keep non-working leg extended or slightly lifted (single-leg emphasis) 🦵 ⚙️ Execution: 1. Movement: • Lower hips slowly, maintaining control (eccentric) ⬇️ • Drive through heel of working leg to thrust hips up, squeeze glutes at top ⬆️ • Avoid hyperextension—focus on glute contraction 🚫 2. Key Cues: • “Drive through the heel” to maximise glute engagement 👣 • “Ribs down” to prevent excessive lumbar arch 📉 • “Squeeze the glute at the top” for 1–2 sec ⏱️ 🩺 Clinical Rehab Considerations: • Hip/Knee Stability: Start with bodyweight or light load for control 🧠 • Glute Activation: Use tactile cues (e.g., hand on glutes) 🖐️ • Asymmetries: Helps address unilateral weakness in post-injury athletes 🩹 🏋️ Performance Applications: • Strength: Progressively overload barbell 📈 • Power: Add pulse or explosive thrust (e.g., for sprinters) ⚡ • Core Challenge: Hold offset weight (e.g., kettlebell in one hand) 🪨💥 ⚠️ Common Mistakes: • Knee Collapse: Align knee with 2nd toe (use band for feedback) 🚫🦵➡️ • Low Back Arch: Tuck pelvis slightly 🔁 • Hamstring Cramping: Reduce range if needed ❗ 🔄 Progressions/Regressions: • Regression: Double-leg → Single-leg (off bench) → Floor ↘️ • Progression: Add tempo (e.g., 3-sec eccentric), or unstable surface (e.g., foam pad) ⏳🧘‍♂️ 🚫 Contraindications: Avoid with acute lumbar or hip pathology (modify to bilateral or reduce ROM) 🚷🩺 💡 Excellent for bridging rehab to performance—improves glute strength while challenging unilateral stability. Let me know if you want modifications (e.g., post-op ACL, low back pain) 🧑‍⚕️

Acute: Chronic Workload Ratio (ACWR) 📊 Gabbett et al. (2016) proposed the concept of the acute: chronic workload ratio (ACWR) where acute workload is purported to reflect the fatigue aspect of Banister’s model with chronic workload representing fitness. Carbone et al. (2022) highlight ACWR facilitates individual performance development & injury prevention management through the relationship between the acute & chronic workload data. Internal (e.g.,Heart rate;session-rate of perceived exertion [sRPE]) & external (e.g.,tracking variables) load measures should be monitored, & used to calculate ACWR during training & competition (Malone et al., 2017). What ACWR? ACWR expresses the relationship between the work from one week to the next (7-day vs a 28-day period). It gives clues into whether an athlete’s recent training load is about right, too low or a risk. Formula: ACWR = Acute Load/Chronic Load Why It Matters ✅Optimise performance 📋Keep track of athlete readiness 🛡️Reduce injury risk Two Models of ACWR 1.⁠ ⁠Rolling Average Model🔄 Acute & chronic load are presented as equal weighted moving averages. Eg: Acute workload=1400 AU Chronic workload=1500 AU ACWR = 1400/1500=0.93 2.⁠ ⁠EWMA: Exponentially Weighted Moving Average 📉 🟠More recent training is given greater weight 🟢Better reflects how fitness & injury risk change over time 🔵Accounts for the decay in training effect as well as non-linear injury risk Injury Risk Zones (Rolling Model Example) 🚨 ACWR Ratio| Interpretation |Relative Injury Risk < 0.80➡️ Under Training ⚠️ Higher Risk 1.80–1.30➡️ Optimal Load ✅ Lowest Risk 1.50➡️ Over Training–Danger Zone ❌ Highest Injury Risk Injury Prevention Tips 🏥 🔺Stay away from training load spikes over 10% 🔻Tapering 40-60% of volume in a super-compensation week 📈 Maintain a high chronic load for building fitness & resilience. Summary📝 The ACWR offers a snapshot of the load history Useful for: 📅Planning effective training periods 🚩Recognize red flags for injury risk 📚Evidence-based decision making for athlete development 📖 1.⁠Carbone et al. 2022. /10.3390/jcm11195945 2.⁠ ⁠Gabbett et al. 2016. /10.1136/bjsports-2015-095567

🚴‍♂️ Chasing performance? Here’s what top athletes actually rely on: smart training, science-backed nutrition, and precision pacing — not shortcuts. While nicotine can give a quick adrenaline kick, it also raises cortisol, which can hinder recovery and long-term gains. That “boost” may be doing more harm than good. ✅ Better, proven alternatives: 🔹 Beetroot juice (nitrate-rich) for improved blood flow 🔹 Timed caffeine (gels/chews) for energy without the crash 🔹 Mindfulness training to build real mental endurance Train smarter. Fuel better. Perform longer. #Prehab #Rehab #InjuryPrevention #SportsRehab #SportsInjury #PerformanceRehab #SportsScience #RehabJourney #SportsPerformance #InjuryRehab #SportsRehabilitation

🔬 Open-Chain Hip Rotation for Isolated ControlControl 🔬 Developing isolated rotational control of the hip in an open-chain position is essential for optimising joint mechanics, enhancing neuromuscular coordination, and reducing compensatory movement patterns. These exercises specifically target the transverse plane of motion, improving the activation and control of deep stabilising muscles that are often underutilised—crucial for both rehabilitation and performance enhancement. 🧠 Biomechanics tip: 👉 Ankle OUT = Hip IN (IR) 👉 Ankle IN = Hip OUT (ER) 🔁 Try these drills: 1️⃣ Prone Hip IR Lie prone with a small Pilates ball under the knee, externally rotate the ankle to internally rotate the hip. 🎯 Targets: Anterior glute med, TFL ✅ 2–3 sets | 8–12 reps 2️⃣ Supine Hip ER Lie supine, internally rotate the ankle to externally rotate the hip. 🎯 Targets: Deep hip rotators (like the piriformis) ✅ 2–3 sets | 10–15 reps 🎯 Purpose: Isolate rotational control in open chain; prep for weight-bearing progressions. (Fixed biomechanics: Ankle ER ➡️ Hip IR / Ankle IR ➡️ Hip ER.) #Prehab #InjuryPrevention #SportsRehab #SportsInjury #PerformanceRehab #SportsScience #RehabJourney #SportsPerformance #InjuryRehab #SportsRehabilitation

Applying Heart Rate Variability to Monitor Health and Performance in Tactical Personnel: A Narrative Review According to Stephenson et al. (2021), Heart–rate variability (HRV) is a non–invasive metric used in tactical populations to measure autonomic nervous system (ANS) activity, including readiness, workload, and recovery 🧠💪. HRV reflects the balance between the sympathetic (SNS) and parasympathetic (PNS) systems, which control heart rate and body responses critical for tactical performance. HRV, derived from beat-to-beat intervals (IBI) ❤️, provides insights into adaptability, stress, and recovery levels. Metrics like rMSSD, HF, and TP—based on time and frequency domain analysis—reflect parasympathetic activity and are used to quantify training load, prevent overtraining 💤, and optimise recovery 🔄. Field training demands high fitness levels. Inadequate recovery can lead to chronic fatigue and reduced readiness. HRV monitors, such as chest-worn devices, track heart rate and internal responses to external loads, offering real-time biofeedback to improve self-regulation 📉. HRV is useful for assessing aerobic fitness, cognitive performance 🧠, and stress resilience. Higher HRV is linked to greater coping and performance ability. Recovery methods like flotation, cryo-stimulation, and cold-water immersion may improve HRV and support ANS balance 🧊. Reliable recordings (1–2 weeks for baseline, 28-day averages for trends) are essential for tailored training and recovery, though device reliability and context matter. Overall, HRV supports training management, overtraining prevention, stress evaluation, and return-to-duty decisions—but is not diagnostic for medical conditions. 📖
Stephenson, M. D., Thompson, A. G., Merrigan, J. J., Stone, J. D., & Hagen, J. A. (2021). Applying Heart Rate Variability to Monitor Health and Performance in Tactical Personnel: A Narrative Review. International Journal of Environmental Research and Public Health, 18(15), 8143. /10.3390/ijerph18158143 #PureScience #Sports #InjuryPrevention #SportsRehab #SportsInjury #PerformanceRehab #SportsScience #RehabJourney #SportsPerformance #InjuryRehab #SportsRehabilitation

🧠 Let’s break it down: What is carbohydrate loading? Carbohydrate loading (aka “carb-loading”) is the science-backed method of maximising your body’s glycogen stores — the primary energy source your muscles rely on during prolonged endurance exercise. ⏱️ Timing is Everything: Eating a large plate of pasta the night before it’s too little, too late. Your muscles and liver can only store a limited amount of glycogen at a time, and it takes multiple meals over 48–72 hours to fully saturate these reserves. ✅ Proper Carb-Loading Strategy (3 Days Out) Here’s how to carb-load effectively 🔹 72–48 Hours Before the Race: •⁠ ⁠Increase your carbohydrate intake to 7–10g of carbohydrate per kg of body weight per day. •⁠ ⁠Prioritise low-fiber, familiar, easily digestible carbs. •⁠ ⁠Slightly reduce fat and protein to make room for extra carbs. •⁠ ⁠Reduce training volume to allow glycogen to build up — don’t burn it as fast as you eat it. 🔹 24 Hours Before the Race: •⁠ ⁠Keep carbs high but avoid unfamiliar or high-fiber foods. •⁠ ⁠Eat small, frequent meals to keep your gut comfortable and avoid overloading. •⁠ ⁠Stay well-hydrated with water and electrolyte drinks. 🔹 Race Morning: •⁠ ⁠Eat a high-carb, low-fiber breakfast about 2–3 hours before the start. 🧪 Science Behind the Strategy •⁠ ⁠Your muscles store about 300–400g of glycogen, and your liver stores about 80–100g. •⁠ ⁠Glycogen is your body’s premium fuel for sustained performance. Once it’s depleted, fatigue sets in fast. •⁠ ⁠Studies show that proper carbohydrate loading can improve performance by up to 2–3% in endurance events lasting longer than 90 minutes. •⁠ ⁠Glycogen is stored with water — for every gram of glycogen, you retain ~3g of water. 🎯 Bottom Line: Carb-loading is a strategic build-up — not a single meal. Think of your glycogen stores like a battery. You don’t wait until it’s empty and expect a single jolt to bring it back to full charge. You charge gradually over days to ensure full, sustained energy output. Fuel wisely. Start early. Race smart #comrades2025training #ultramarathon #comrades #training #nutrition #running

💪🏽 Strengthening the Shoulder with Anti-Rotation Control: A Rehabilitation-Focused Plank Variation 🟠 This advanced plank variation targets shoulder stability, core control, and rotator cuff endurance—particularly useful for rehabilitating an injured shoulder while maintaining scapular and trunk stability. Execution: 1️⃣ Begin in a straight-arm plank position with your shoulders stacked directly over your wrists and your core engaged to maintain a neutral spine. ⚖️ Place a small Pilates ball (or a lightweight dumbbell/kettlebell) under one hand. The unstable surface increases proprioceptive demand. 🔁 While maintaining a plank (no hip sagging or hiking), slowly rotate the ball in small, controlled circles. The key is to resist rotational forces through the torso, emphasising anti-rotation core engagement. 🛑 Keep the movement slow and deliberate, ensuring the shoulder remains stable and the scapula does not excessively protract or wing. Benefits: 🌀 Rotator cuff activation – The controlled circular motion under load enhances dynamic stabilization of the glenohumeral joint. 🔗 Scapulothoracic control – Promotes proper scapular positioning and endurance in a closed-chain position. 🧱 Core integration – The anti-rotation demand recruits the obliques and transverse abdominis, reinforcing trunk stability during upper limb movement. 📈 Rehab progression – Ideal for later-stage shoulder rehab where controlled eccentric loading is needed without compromising form. Programming Considerations: 🔢 Start with 2-3 sets of 6-8 circles per side, ensuring perfect form before increasing volume. ⚠️ If pain occurs during the movement, regress to a static plank with no ball or reduce the circle diameter. Who Should Use This Exercise? 🏊‍♀️ Post-rehabilitation athletes returning to overhead sports (swimming, tennis, padel). 🛡️ Individuals with a history of shoulder instability or impingement looking to improve dynamic control. #Prehab #Rehab #InjuryPrevention #SportsRehab #SportsInjury #PerformanceRehab #SportsScience #RehabJourney #SportsPerformance #InjuryRehab #SportsRehabilitation

Gender-Specific Caffeine Effects ☕♀️♂️ Domaszewski (2023) examined gender differences in positive and negative responses after acute caffeine intake. 1. Gender Differences & Negative Effects ⚠️ Significant gender-based differences were observed in negative effects one hour after intake, especially in the ES group (p = 0.049). About 30% of men and 54% of women reported adverse effects. This supports Pez-Graniel’s findings that anxiety and nervousness were three times more common in women than men. 2. Positive Benefits & Gender Differences ✨ Caffeine had stronger positive effects in men: • Improved perception (p = 0.032) • Increased vigor/activeness (p = 0.009) 50% of men vs. 20% of women reported positive effects. 35% of men and 11% of women experienced greater awareness shortly after intake. 3. Mechanism of Action & Dosage ⚙️ Caffeine works by blocking adenosine receptors that cause tiredness. • FDA recommendation: ≤400 mg/day for the general public • Athletes: ≤6 mg/kg based on lean body mass • High doses (>9 mg/kg): Can cause insomnia, GI issues, and cognitive problems 4. Study Design & Findings 🧪 Participants: • Low/moderate users: 3 mg/kg (n = 34; 14 males, 19 females) • High consumers: 6 mg/kg (n = 31; 16 males, 15 females) Method: QUEST questionnaire at 1 and 24 hours post-intake. Women showed stronger negative responses, possibly due to lower oestradiol. Renal excretion was higher in both sexes, especially in women. 5. Key Takeaways ✅ • Sex plays a key role in caffeine’s effects, likely due to hormonal and body composition differences. • Women: More side effects (54%), fewer benefits • Men: Fewer side effects (30%), more benefits (50%) • Recommendation: Caffeine dosage should be tailored by body weight and lean mass, especially in athletic populations. Reference: Domaszewski P. (2023). Gender Differences in the Frequency of Positive and Negative Effects after Acute Caffeine Consumption. Nutrients, 15(6), 1318. /10.3390/nu15061318 #caffiene #gender #caffineeffects #caffieneaddict