Exercise: The Why, What, and How

Key Takeaways

• Aerobic exercise improves cardiovascular & respiratory fitness as well as metabolic, immune, cognitive, and mental health.

• Strength training exercise improves bone & joint health in addition to benefits of aerobic exercise.

• Aerobic exercise should be done at least 150 minutes per week at moderate intensity. Strength training should be done at least 2 days per week with 8-10 exercises per session.

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The Why

Aerobic exercise has the following benefits immediately after a session:

Improved Cardiovascular (Heart) Function:

• Increased cardiac output and stroke volume

• Improved endothelial function and vasodilation (↑ nitric oxide)

• Post-exercise hypotension: lowered blood pressure for up to 24 hours

• Enhanced blood flow to brain, muscles, and vital organs

Improved Metabolic (Digestion & Sugar Management) Function:

• Increased glucose uptake by skeletal muscle (insulin-independent)

• Improved insulin sensitivity for 24–48 hours

• Increased fat oxidation during recovery

• Elevated metabolic rate (EPOC) for several hours

• Improved appetite hormone signaling (leptin/ghrelin balance)

Improved Cognitive (Brain) Function:

• Increased cerebral blood flow and oxygenation

• Elevated brain-derived neurotrophic factor (BDNF)

• Improved attention, reaction time, and executive function

• Enhanced learning readiness and memory encoding

Improved Mental & Emotional Health:

• Release of endorphins and endocannabinoids

• Release of dopamine, serotonin, and norepinephrine

• Reduced anxiety and stress perception

• Improved mood and emotional regulation

• Decreased sympathetic nervous system activity post-exercise

Improved Immune (Fighting Colds/Flus/Viruses) Function:

• Transient boost in immune surveillance (↑ NK cell activity)

• Acute anti-inflammatory response (↑ IL-10, ↓ TNF-α signaling)

• Improved regulation of immune cell trafficking

• Increased catecholamines during exercise → improved alertness

• Improved cortisol regulation post-exercise

Improved Musculoskeletal (Muscle, Bones, Joints) Function:

• Increased joint lubrication and synovial fluid circulation

• Improved muscle extensibility and temporary flexibility gains

• Enhanced nutrient delivery to cartilage and connective tissue

Improved Respiratory (Lung) Function:

• Increased ventilation efficiency

• Improved oxygen diffusion and utilization

Improved Sleep:

• Improved sleep onset latency

• Increased slow-wave (deep) sleep later that night

• Improved circadian rhythm signaling

• Increased parasympathetic (vagal) tone post-exercise

• Reduced resting heart rate over the following hours

Additional long-term benefits of aerobic exercise, when done regularly, include:

Improved Cardiovascular (Heart) Function:

• Lowered resting blood pressure

• Improved cholesterol profile (↑ HDL, ↓ LDL and triglycerides)

• Enhanced endothelial function and arterial elasticity

• Reduced risk of coronary artery disease, stroke, and heart failure

• Improved cardiac output and heart efficiency

Improved Metabolic (Digestion & Sugar Management) Function:

• Improved insulin sensitivity and glucose regulation

• Reduced risk of type 2 diabetes and metabolic syndrome

• Healthier body composition and fat loss

• Enhanced mitochondrial density and metabolic efficiency

Improved Cognitive (Brain) Function:

• Increased cerebral blood flow and oxygen delivery

• Stimulated neurogenesis and synaptic plasticity (↑ BDNF)

• Improved memory, attention, and executive function

• Reduced risk of cognitive decline, dementia, and Alzheimer’s disease

Improved Mental & Emotional Health:

• Reduced symptoms of depression and anxiety

• Better stress resilience and emotional regulation

• Improved overall mood and sense of well-being

  
  

Improved Immune (Fighting Colds/Flus/Viruses) Function:

• Reduced chronic low-grade inflammation (↓ CRP, IL-6, TNF-α)

• Enhanced immune surveillance and regulation

• Lowered risk of certain infections and inflammation-related diseases

Improved Musculoskeletal (Muscle, Bones, Joints) Function:

• Improved bone mineral density (especially with weight-bearing activity)

• Preserved muscle mass and strength with aging

• Enhanced joint nutrition, cartilage health, and mobility

Improved Respiratory (Lung) Function:

• Increased lung ventilation efficiency

• Improved oxygen uptake and utilization (↑ VO₂max)

• Reduced dyspnea (difficulty breathing) during daily activities

Improved Sleep:

• Enhanced sleep quality and circadian rhythm stability

Reduced Chronic Disease Risk:

• Lowered risk of several cancers (colon, breast, endometrial)

• Reduced risk of hypertension, osteoporosis, and frailty

• Improved outcomes and quality of life in many chronic diseases

• Reduced all-cause mortality risk

  
  

Improved Aging:

• Improved mitochondrial biogenesis and function

• Enhanced antioxidant defense systems

• Improved DNA repair and cellular resilience

• Slowed biological aging markers

• Extended healthspan (years lived without disability)

  
  

Strength training has the following benefits immediately after a session:

Improved Cardiovascular (Heart) Function:

• Temporary increase in cardiac output during exercise

• Post-exercise blood pressure reduction in the hours following

• Improved vascular responsiveness

Improved Metabolic (Digestion & Sugar Management) Function:

• Increased glucose uptake by muscle (insulin-independent)

• Improved insulin sensitivity for 24–48 hours

• Elevated metabolic rate (EPOC) for several hours

• Increased fat oxidation during recovery

Improved Cognitive (Brain) Function:

• Increased central nervous system arousal and focus

• Improved executive function and reaction time post-session

• Enhanced motor learning consolidation

Improved Mental & Emotional Health:

• Increased endorphins and dopamine

• Reduced stress and anxiety

• Improved mood, confidence, and sense of accomplishment

Improved Immune (Fighting Colds/Flus/Viruses) Function:

• Acute anti-inflammatory signaling

• Transient increase in immune cell activity

• Initiation of tissue repair processes

Improved Musculoskeletal (Muscle, Bones, Joints) Function:

• Increased muscle blood flow and nutrient delivery

• Increased motor unit recruitment and firing rate

• Enhanced neuromuscular coordination and muscle activation

• Improved force production and movement efficiency (post-activation potentiation)

• Initiation of muscle protein synthesis (peaks ~24–48 hrs)

• Cellular swelling (“muscle pump”) supporting anabolic signaling

• Acute stimulation of tendon and connective tissue remodeling

• Increased satellite cell signaling for muscle repair and adaptation

• Mechanical loading stimulates osteoblast activity (building stronger bones)

• Increased joint lubrication and synovial fluid circulation

• Improved joint stability through muscular activation

Improved Sleep:

• Improved sleep quality later that night

• Increased slow-wave (deep) sleep, supporting recovery

Additional long-term benefits of strength training, when done regularly, include:

Improved Cardiovascular (Heart) Function:

• Lowered resting blood pressure

Improved Metabolic (Digestion & Sugar Management) Function:

• Improved insulin sensitivity and glucose control

• Increased resting metabolic rate via greater lean mass

• Improved body composition (↓ fat mass, ↑ lean mass)

• Reduced risk of type 2 diabetes and metabolic syndrome

• Improved lipid profile (↓ triglycerides, ↑ HDL)

• Reduced visceral adiposity

Improved Cognitive (Brain) Function:

• Improved executive function and working memory

Improved Mental & Emotional Health:

• Reduced symptoms of depression and anxiety

• Improved self-esteem, confidence, and body image

• Enhanced stress resilience

Improved Musculoskeletal (Muscle, Bones, Joints) Function:

• Increased and preserved muscle mass (prevents sarcopenia- muscle loss with aging)

• Improved muscle strength and power

• Increased bone mineral density (reduces osteoporosis and fracture risk)

• Enhanced tendon and ligament stiffness and resilience

• Improved joint stability and alignment

• Reduced risk of musculoskeletal injury

• Improved neuromuscular coordination and motor unit recruitment

• Enhanced balance, proprioception, and reaction time

• Reduced fall risk, especially in older adults

• Improved functional capacity for daily activities

• Increased satellite cell activity and muscle repair capacity

• Improved mitochondrial function within muscle fibers

Reduced Chronic Disease Risk:

• Reduced risk of frailty and disability

• Improved outcomes in arthritis, back pain, and osteoarthritis

• Reduced cancer-related fatigue and improves survivorship outcomes

• Improved quality of life in many chronic conditions

Improved Aging:

• Preserved independence and mobility with aging

• Extended healthspan (years lived with strength, not just years lived)

The What

Aerobic exercise is any physical activity that uses large muscle groups, can be sustained continuously, and relies primarily on oxygen-dependent (aerobic) energy pathways to meet the body’s energy demands.

It includes these types of activities

1. Walking (leisurely or brisk)

2. Gardening or yard work

3. Housework (vacuuming, mopping, cleaning)

4. Cycling (outdoor or stationary)

5. Swimming

6. Jogging or running

7. Hiking

8. Dancing (social dancing, Zumba, aerobics classes)

9. Elliptical trainer

10. Rowing (machine or on water)

11. Water aerobics

12. Playing with children (active play, tag, playground games)

13. Climbing stairs

14. Cross-country skiing

15. Jumping rope

16. Skating (ice or roller skating)

17. Tennis (singles or doubles)

18. Basketball (recreational play)

19. Soccer (recreational play)

20. Yoga flow or Pilates (continuous, movement-based styles)

Strength training exercise is any physical activity in which muscles work against an external resistance to produce force, with the goal of maintaining or increasing muscle strength, power, endurance, or size.

It includes these types of activities 

1. Weightlifting (free weights or machines)

2. Bodyweight exercises (push-ups, squats, lunges, planks)

3. Resistance band exercises

4. Yoga (poses that support body weight, e.g., planks, chair pose)

5. Pilates

6. Push-ups against a wall or countertop

7. Pull-ups or assisted pull-ups

8. Climbing stairs while carrying items

9. Carrying groceries or heavy bags

10. Lifting and putting away laundry or boxes

11. Shoveling snow or dirt

12. Digging, raking, or heavy gardening

13. Moving furniture or household items

14. Carrying a child or lifting a stroller

15. Manual labor (construction, landscaping tasks)

16. Rock climbing or bouldering

17. Rowing (machine or on water)

18. Kettlebell training

19. Functional training or circuit training

20. Isometric exercises (wall sits, static holds)

The How

You’ll see the most benefits of aerobic exercise at “moderate intensity” for at least 150 minutes per week (about 5 days per week of 30 minutes per session). Moderate intensity is considered exercise at 65-75% of your maximal heart rate. Unless you have access to a formal VO2max test, the estimate of HRmax=220-age is sufficient. See the table below to estimate your moderate intensity range based on age:

Age	Estimated HRmax	65% HRmax	75% HRmax
15 years	205bpm	133bpm	154bpm
20 years	200bpm	130bpm	150bpm
25 years	195bpm	126bpm	146bpm

To check your heart rate while exercising, wear a heart rate monitor, smart watch, or use a clock. When using a clock, check your pulse at your neck or wrist and count the beats for 6 seconds. Multiply the number of beats during that 6 seconds by 10 to get an estimate of your heart rate in beats per minute.

You’ll see the most benefits of strength training if you train all major muscle groups on 2-3 days per week, 8-10 exercises per session. In general, 2-3 sets of 8-12 repetitions per exercise is sufficient. Having muscle soreness, or DOMS (delayed onset muscle soreness), is expected but if it lasts more than 2 or 3 days, you probably made the session too intense.

Bottom Line

Exercise is one of the single best things you can do for your growth, health, and happiness. Even daily tasks and lighter intensity exercise can add up. Try 10 minutes at a time, and see where it gets you.

If you're having trouble starting an exercise plan due to pain, disability, or another physical barrier, be sure to seek out physical therapy. Your physical therapist can help you find the best way to access these unparalleled benefits of exercise!