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📖 Movement & Exercise Sources

Sources for training, physical activity, and exercise science.

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Key Research Findings Summary​

Cardiovascular Fitness and Mortality​

  • 1 MET increase in cardiorespiratory fitness = 14% reduction in mortality risk
  • Low VO2 max is a stronger mortality predictor than smoking, diabetes, or hypertension
  • 10-25% survival improvement with fitness across risk populations
  • Each 3.5 mL/kg/min increase in VO2 max associated with significant mortality reduction

Resistance Training and Hypertrophy​

  • Load independence for hypertrophy: Similar muscle growth across load ranges when volume equated and effort high
  • High loads superior for strength: When volume equal, highest loads induce superior dynamic strength gains
  • Both load and rep progression work: 2024 research shows both are viable strategies for 8-week cycles
  • MPS elevated 24+ hours post-exercise: 2024 systematic review confirms sustained anabolic response
  • Older adults show attenuated MPS response: ~44% vs ~93% in younger adults

Zone 2 Training​

  • Expert consensus centers on lactate threshold 1 (LT1) or ventilatory threshold 1 (VT1)
  • Individual variability in lactate thresholds can cause "zone mis-assignment"
  • 3-6 hours/week recommended for recreational athletes
  • Builds mitochondrial density and fat oxidation capacity

HIIT Research​

  • 2024 umbrella reviews show SMD 0.28-4.31 for cardiorespiratory fitness improvements
  • Effective across diverse populations (healthy, clinical, elderly)
  • Time-efficient for improving VO2 max
  • Norwegian 4x4 protocol well-researched

Flexibility and ROM​

  • Static/PNF stretching superior for long-term ROM gains vs dynamic stretching (2024 meta-analysis)
  • Resistance training improves ROM: Full ROM resistance training as effective as stretching
  • 65 studies show chronic stretching increases joint ROM when performed ≥2 weeks
  • Females show higher ROM gains than males from stretching

Recovery and Detraining​

  • VO2 max declines within 2-4 weeks of detraining but remains above untrained baseline
  • Cardiac adaptations (athlete's heart) show reverse remodeling within weeks of detraining
  • Adaptations can be maintained with reduced training if intensity preserved
  • MPS can be stimulated with 20-25g protein post-exercise

Key Sources​

Source Tier Definitions
  • Tier A: Systematic reviews, meta-analyses, RCTs in high-impact journals
  • Tier B: Organization guidelines, textbooks, peer-reviewed primary research
  • Tier C: Expert commentary, interviews, evidence synthesis from practitioners

Cardiovascular Fitness & VO2 Max​

Meta-Analyses and Reviews​

  • Cardiorespiratory fitness and mortality — Myers et al., NEJM (2002) — Tier A
    • Landmark study: each 1-MET increase = 12-14% lower mortality
  • VO2 max as mortality predictor — Kodama et al., JAMA (2009) — Tier A
    • Meta-analysis: low CRF = higher mortality than smoking
  • Health benefits of physical activity — Warburton et al. (2017) — Tier A
    • Comprehensive review of exercise health outcomes
  • Cardiovascular effects of exercise training — Myers (2003) — Tier A
    • Mechanisms of CV adaptation

Zone 2 Research​

  • Zone 2 training consensus — Expert interviews (San Millan, Seiler) — Tier C
    • LT1/VT1 as Zone 2 marker; individual variability
  • Polarized training model — Seiler et al. — Tier B
    • 80/20 distribution; elite endurance athletes

Resistance Training & Hypertrophy​

Systematic Reviews and Meta-Analyses​

  • Load and hypertrophy — Schoenfeld et al., J Strength Cond Res (2017) — Tier A
    • Hypertrophy similar across loads when effort equated
  • Overload progression protocols — Int J Sports Med (2024) — Tier A
    • Load vs rep progression both viable for strength/hypertrophy
  • Progressive overload and muscular adaptations — PMC (2022) — Tier A
    • Load or repetition progression both promote gains
  • Maximizing muscle hypertrophy — Schoenfeld et al., PMC (2019) — Tier A
    • Review of advanced resistance training techniques
  • Volume and hypertrophy dose-response — Schoenfeld et al. (2017) — Tier A
    • 10-20 sets/muscle/week optimal
  • Training frequency meta-analysis — Schoenfeld et al. (2016) — Tier A
    • 2x/week per muscle superior to 1x
  • Progressive resistance in older adults — J Strength Cond Res (2022) — Tier A
    • Increases strength (SMD 1.1) and bone density

Muscle Protein Synthesis​

  • MPS response to resistance exercise — Davies et al., Transl Sports Med (2024) — Tier A
    • MPS elevated post-RE, sustained past 24h; older adults attenuated response
  • Protein and MPS — Int J Sport Nutr Exerc Metab (2024) — Tier A
    • No upper limit to postprandial MPS duration
  • Post-exercise protein synthesis — Phillips et al. — Tier A
    • 20-25g protein maximally stimulates MPS

HIIT Research​

  • HIIT umbrella review — Sports Med (2024) — Tier A
    • SMD 0.28-4.31 for CRF; effective across populations
  • HIIT and cardiovascular health — Multiple meta-analyses — Tier A
    • Improves VO2 max, metabolic health
  • Norwegian 4x4 protocol — Wisloff et al. — Tier B
    • Well-researched interval protocol

Flexibility and Mobility​

  • Chronic stretching and ROM — Konrad et al., J Sport Health Sci (2024) — Tier A
    • Static/PNF superior to dynamic for long-term ROM; females show greater gains
  • Acute stretching effects — Behm et al., Sports Med Open (2023) — Tier A
    • Systematic review of stretching techniques
  • Resistance training and ROM — Alizadeh et al., Sports Med (2023) — Tier A
    • RT improves ROM; full ROM training recommended
  • Mechanisms of ROM improvement — Systematic review (2024) — Tier A
    • 65 studies; stretch tolerance and tissue changes

Recovery Science​

  • Recovery strategies review — ScienceDirect (2019) — Tier A
    • Nutritional interventions have strongest evidence
  • Sleep and athletic performance — Vitale et al. (2019) — Tier A
    • Sleep quality critical for adaptation
  • Post-exercise recovery — Bishop et al. (2008) — Tier A
    • Recovery modalities comparison

Detraining and Reversibility​

  • Cardiorespiratory consequences of detraining — Front Physiol (2024) — Tier A
    • VO2 max declines; metabolic/hormonal changes; adaptations retained with reduced training
  • Cardiac reverse remodeling — Eur Heart J (2024/2025) — Tier A
    • Olympic athletes: LV/RV volume decreases within weeks of detraining
  • Detraining and physiological adaptations — Mujika & Padilla (2000) — Tier A
    • Landmark review on adaptation loss timelines

Sources by Topic​

Click to expand sources organized by topic area

Cardiovascular Training (cardio.md)​

  • Cardiorespiratory fitness and mortality (Myers, Kodama)
  • Zone 2 training research (San Millan, Seiler)
  • HIIT studies and protocols
  • VO2 max as health marker

Strength Training (strength.md)​

  • Hypertrophy mechanisms (Schoenfeld)
  • Volume and frequency meta-analyses
  • Progressive overload research (2024)
  • Load vs rep progression studies

Flexibility & Mobility (flexibility.md)​

  • ROM meta-analyses (Konrad, Behm)
  • Resistance training and flexibility
  • Stretching type comparisons

Recovery (recovery.md)​

  • Recovery strategies review
  • Sleep and athletic performance (Vitale)
  • Post-exercise nutrition and MPS

Adaptations (adaptations.md)​

  • Exercise adaptation timelines
  • Concurrent training interference
  • Detraining studies (Mujika, 2024 reviews)

Program Design (program-design.md)​

  • Periodization theory (Bompa)
  • Volume landmarks research
  • NSCA programming guidelines
Where to Begin
  1. For cardiovascular health: Cardiorespiratory fitness and mortality (Myers)
  2. For strength/hypertrophy: Schoenfeld meta-analyses
  3. For Zone 2: San Millan and Seiler interviews/research
  4. For programming: NSCA Essentials + Stronger By Science
  5. For evidence synthesis: Stronger By Science resources

→ Return to Sources Hub for full source details and cross-references