Exercise Study Guide

📖 Core Concepts Exercise – Planned, repetitive physical activity that improves or maintains fitness and health. Aerobic vs. Anaerobic – Aerobic uses large muscles, raises O₂ consumption, builds cardiovascular endurance; anaerobic (strength/resistance) uses high‑intensity bursts, builds muscle mass, bone density, and coordination. Flexibility – Stretching that lengthens muscle‑tendon units to increase joint range of motion and lower injury risk. Intensity Zones – Moderate: 50‑70 % max HR; Vigorous: 70‑85 % max HR. Dose‑Response – 150 min/week moderate or 75 min/week vigorous activity yields most health benefits; even 2‑3 min/day lowers premature‑death risk ≈10 %. J‑shaped Immunity Curve – Low‑to‑moderate activity ↑ immunity; high‑intensity, prolonged bouts (e.g., marathons) ↓ immunity temporarily. --- 📌 Must Remember Guideline Dose: ≥ 150 min moderate or ≥ 75 min vigorous aerobic plus ≥ 2 days/week muscle‑strengthening. Protein for Hypertrophy: ≈ 1.6 g kg⁻¹ day⁻¹ (with resistance training) maximizes MPS. Cardiovascular Benefit Peak: 40‑60 % VO₂max (moderate intensity) gives greatest reduction in CVD risk. Immune Effect: Moderate exercise ↓ URTI incidence 29 %; high‑intensity → transient ↑ infection risk. Neuroplasticity Marker: Acute aerobic bouts ↑ BDNF → short‑term cognitive boost; chronic training sustains the rise. Overtraining Signs: Persistent fatigue, performance plateau/decline, increased infections, mood disturbances. --- 🔄 Key Processes Resistance‑Training Muscle Hypertrophy Mechanical tension → mTOR activation → ↑ muscle‑protein synthesis (MPS). Protein‑rich meal post‑session → sustains MPS, suppresses MPB. Aerobic Cardiovascular Remodeling Repeated volume overload → ↑ stroke volume & cardiac output. Shear stress → endothelial NO production → vasodilation & lower resting BP. Myokine Release Contracting muscle secretes IL‑6, irisin, myostatin regulators → anti‑inflammatory, tissue‑repair signaling. Mitochondrial Biogenesis (Endurance) ↑ PGC‑1α expression → new mitochondria → higher oxidative capacity, delayed fatigue. Neurotrophic Cascade Exercise ↑ BDNF, IGF‑1, VEGF → hippocampal neurogenesis & improved memory. --- 🔍 Key Comparisons Aerobic (steady‑state) vs. HIIT Steady‑state: Improves basal BP, lipid profile, endurance. HIIT: Greater ↑ VO₂max, ↓ arterial stiffness, shorter time commitment. Dynamic vs. Static Exercise (BP effect) Dynamic (running): ↓ diastolic BP during activity (improved flow). Static (weight‑lifting): Transient ↑ systolic BP (vascular resistance). Resistance Training (Low vs. High Load) in Older Adults Low load (30‑40 % 1RM, high reps): Improves muscular endurance. High load (≥ 70 % 1RM): Best for muscle power & hypertrophy. Moderate vs. Prolonged High‑Intensity Exercise (Immune) Moderate: ↑ NK‑cell activity, ↓ CRP. Prolonged high‑intensity: ↓ NK activity, ↑ infection risk. --- ⚠️ Common Misunderstandings “More is always better.” – Excessive high‑intensity training can suppress immunity and trigger overtraining. “Only cardio matters for heart health.” – Strength training also improves intra‑arterial BP responses and cardiac remodeling. “Flexibility is optional.” – Lack of flexibility raises injury risk and limits functional mobility. “Protein only matters on rest days.” – Post‑exercise protein is critical for maximizing MPS. --- 🧠 Mental Models / Intuition “The 150‑Minute Bucket” – Imagine a weekly bucket that must hold at least 150 min of moderate activity; any spillover (vigorous minutes) counts as “double‑filled” (2 min vigorous = 4 min moderate). “Fuel‑and‑Repair Cycle” – Exercise = fuel burn (energy deficit) → signal for repair (muscle, vascular, neural); nutrition = the building blocks that complete the repair. “J‑Shape Ladder” – Visualize immunity on a ladder: start low (sedentary), climb to optimal (moderate), then slip down if you over‑climb (excessive intensity). --- 🚩 Exceptions & Edge Cases Pregnant Women – Moderate activity safe; avoid high‑impact or high‑temperature environments. Cancer Survivors – Higher‑intensity aerobic exercise reduces fatigue more than low‑intensity, but must be tailored to treatment stage. Older Adults with Osteoporosis – Weight‑bearing and resistance work improve bone density, but must start with low load to avoid fracture. Individuals with Chronic Inflammation – Myokine‑mediated anti‑inflammatory effects may be blunted; combine exercise with anti‑inflammatory diet. --- 📍 When to Use Which Goal: Improve VO₂max → Choose HIIT or continuous moderate‑intensity aerobic ≥ 3 sessions/week. Goal: Increase Muscle Mass → Progressive resistance 2–3 ×/week + 1.6 g kg⁻¹ day⁻¹ protein. Goal: Enhance Flexibility/Prevent Injury → Daily static stretching post‑workout + dynamic warm‑ups pre‑workout. Goal: Boost Immune Surveillance (e.g., during flu season) → Keep sessions ≤ 60 min, moderate intensity, avoid consecutive high‑intensity days. Goal: Reduce Blood Pressure → Moderate aerobic + low‑to‑moderate resistance (2 ×/week). --- 👀 Patterns to Recognize “Dose‑Response Curve” – Health benefit rises steeply up to ≈ 150 min/week then plateaus; extra minutes yield diminishing returns. “Symptom Cluster of Overtraining” – Fatigue + performance drop + mood change + ↑ resting HR = red flag. “Cross‑Training Benefits” – Adding a different modality (e.g., strength to an aerobic program) often yields synergistic cardiovascular and musculoskeletal gains. “Acute vs. Chronic Cognitive Gains” – Short‑term bouts → transient ↑ attention; long‑term training → sustained memory improvements. --- 🗂️ Exam Traps “All high‑intensity exercise is harmful.” – True only when prolonged; short HIIT sessions are beneficial for VO₂max and arterial health. “Flexibility training burns calories like cardio.” – Stretching improves range of motion but has minimal caloric impact. “Protein timing is irrelevant.” – Post‑exercise protein within 2 h maximizes MPS; ignoring timing reduces hypertrophy gains. “Only 150 min of moderate activity matters.” – Any amount counts; 2–3 min/day already confers measurable mortality reduction. “Strength training raises systolic BP permanently.” – Acute rise occurs during lifts; chronic training typically lowers resting BP. ---