How Heat and Hydration Affect Muscle and Joint Health
Stiff, painful joints and muscles don't just happen when it's cold outside. Heat and dehydration can also be factors in pain and stiffness. When temperatures rise, taking a few precautions can help you avoid sore, stiff joints and muscles.
How Heat Affects Muscles and Joints
Blood vessels dilate, or widen, causing stiff, swollen joints during hot weather. As joints stiffen, range of motion decreases, which can affect flexibility whether you're going for run or pruning shrubbery. Although joint changes can happen to anyone, people with arthritis or other conditions may be more likely to experience heat-related issues.
Muscle fatigue occurs much sooner than normal when it's hot. The problem happens when your body increases blood flow to your skin to assist in cooling. Unfortunately, this means that your muscles receive less blood and soon become fatigued.
You're more likely to experience injuries, like strains and sprains, when your muscles are tired. Fatigued muscles can also be a factor in joint injuries. Tired muscles struggle to support joints, which also increases the risk of injury.
The Effect of Hydration on Muscles and Joints
Water is essential to the health of your tissues and joints. When fluid levels decrease, dehydration occurs. Dehydration can cause thirst, decreased urine output, dry mouth, fatigue, and headache. Without enough water, your muscles may begin to cramp painfully.
Dehydration affects the joints by decreasing synovial fluid amounts. The fluid circulates around joints, providing the lubrication needed to move easily. When synovial fluid levels drop, joints can become stiff and painful.
Muscles have a high water content. When you're dehydrated, your muscles must work harder and may become fatigued or strained more easily. It also takes your muscles longer to recover from physical activity if you're dehydrated.
The combination of hot, humid conditions and dehydration can lead to microdamage of skeletal muscles, according to a research study published in the Journal of Athletic Training in 2005. Skeletal muscles are attached to bones and help you move your body. Researchers noted that participants who walked on a treadmill in a hot, humid room with restricted fluids were more likely to experience microdamage than those who received oral fluids.
Hydration is particularly important as you age. A research study published in Nutrients in 2019 noted that a higher intercellular water content/lean mass ratio in people 75 and older was associated with better muscle strength and function. Older people with better hydration also had a reduced risk for frailty.
Poor hydration also affects the condition of:
- Spinal Discs
- Tendons
- Cartilage
Without enough fluid, these structures may become less flexible and more prone to injury.
5 Ways to Protect Joints and Muscles This Summer
Keeping joints and muscles strong and healthy can be as simple as:
- Improving Hydration. Increase the amount of water you drink on hot, humid days. If you feel thirsty, you may already be dehydrated. Be sure to drink before, during, and after you exercise.
- Stretching. Stretching can help you avoid strains and sprains, but timing matters on hot, humid days. Stretch in the morning or during the coolest part of the day.
- Timing. Scheduling outdoor activities or exercise for the early morning or evening hours when heat and humidity is less intense. Limiting vigorous or intense activities to these times will help you avoid dehydration and sore, stiff muscles.
- Paying Attention to Your Body. Muscle cramps, dark urine, fatigue, and extreme thirst can be signs of heat exhaustion or heatstroke. If you experience these symptoms, drink more water and find a cool place to rest. If symptoms don't improve, seek emergency treatment.
- Visiting Your Chiropractor. Chiropractic treatments, like adjustments and soft tissue therapies, reduce muscle tension, improve range of motion in joints, and boost circulation, helping you stay pain-free during summer weather. During your appointment, your chiropractor looks for subluxations, or misaligned vertebrae, and joint restrictions that could stress muscles and soft tissues. Correcting these issues with chiropractic therapies could help you avoid heat-related pain and injuries.
Chiropractic treatment is essential for good joint and muscle health when temperatures soar. Contact our office to schedule an appointment with the chiropractor.
Sources:
Journal of Athletic Training: Dehydration and Symptoms of Delayed-Onset Muscle Soreness in Hyperthermic Males, 10-12/2005
https://pmc.ncbi.nlm.nih.gov/articles/PMC1323290/
Centers for Disease Control and Prevention: Heat-Related Illnesses, 3/3/2026
https://www.cdc.gov/niosh/heat-stress/about/illnesses.html
Nutrients: Intracellular Water Content in Lean Mass is Associated with Muscle Strength, Functional Capacity, and Frailty in Community-Dwelling Elderly Individuals. A Cross-Sectional Study, 3/19/2019
https://pmc.ncbi.nlm.nih.gov/articles/PMC6471552/
Cleveland Clinic: Heat Cramps, 3/31/2023
https://my.clevelandclinic.org/health/diseases/24866-heat-cramps
American Physiological Society: Heat Stress May Affect the Muscles for Longer Than We Think, 2/13/2024
