Summer Exercise and Hydration   

Have you heard someone make the following comment? “If I’d known I’d live this long, I’d have taken better care of myself.

The quote reflects a common regret about not prioritizing health and well-being earlier in life. Of course, it’s easy to neglect healthful habits when you are younger or don’t feel obvious consequences from this neglect. Part of the aging process for almost everyone seems to be increased aches and pain as well as more health care visits. There is also recognition of diminished strength and stamina for the normal physical activities that were undertaken earlier in life. Attending doctors at medical appointments often suggest that current problems are associated with less than healthy behavioral habits.

We are seeing more and more research that suggests the critical need for seniors to undertake at least moderate levels of regular exercise. Different forms of exercise are recommended for maintaining the strength of various muscles, cardiovascular fitness, body flexibility, and balance. Seniors sometimes use dedicated machines, barbells, dumbbells, and resistance bands whether in local gyms, fitness parlors, or at home.  

Decades ago, I played a lot of youth and adolescent baseball in the extreme heat of Louisiana summers. My coach then advised us to bring a piece or two of rock salt to lick during our practices and games. Later when I worked in the bull gang several summers at the Olinkraft pulp and paper mill, there were many containers placed throughout the plant that were filled with salt tablets. We were encouraged to consume these tablets on hot days. I didn’t understand well then why salt intake was considered that important.   

The salt tablet advice from decades past was apparently based on a partially correct, but oversimplified, understanding of heat-related physiology that had some dangerous implications. Yes, heavy sweating depletes both water and sodium, and replacing only water can lead to hyponatremia or dangerously low blood sodium. Unfortunately, salt tablets then had highly concentrated sodium chloride that could cause severe gastric irritation, nausea, and vomiting – not what you want during heat stress. Even worse, people often took this salt without adequate water, which could worsen dehydration by drawing water into the digestive tract. We now understand that sodium replacement works best when combined with appropriate amounts of water and other electrolytes like potassium and magnesium.

Today's approach favors gradual electrolyte replacement through properly formulated drinks, foods with appropriate content, or diluted electrolyte solutions rather than through concentrated tablets that can shock the digestive system. Individual differences matter much more than realized decades ago. Not everyone sweats at the same rate or loses the same level of electrolytes. Some people need more sodium replacement, while others need less. Modern recommendations focus more on monitoring individual symptoms and urine color rather than offering blanket advice about supplements.

Appropriate hydration seems especially important for those over 50 who are engaging in sport activities for cardiovascular benefits or doing weight training to avoid muscle atrophy. Beyond simply drinking more water, seniors engaging in sports and exercise activities need more nuanced approaches. Timing matters more than total volume. Pre-hydration becomes important, since older adults have diminished thirst sensation and slower kidney function. Hydration should start well before exercise, not just during or after it. Small, frequent sips throughout the day work better than large amounts consumed quickly.

The post-exercise period is when many seniors inadvertently become dehydrated despite drinking during the activities. I noticed this personally when I used to work beehives for hours during the summer heat. My finger joints and leg muscles would start cramping hours after beekeeping or active sports sessions. It would often take a quart or more additional water to begin to relieve these cramps.

I can be a slow learner about topics such as exercise during the summer and hydration needs. You become accustomed to normal water consumption levels during much of the year or just drink fluids when you’re thirsty – without apparent consequences. The heat and humidity of late spring, summer, and early fall in the Deep South, though, can lead to painful or deadly results for those exposed over hours to these conditions. Climate change with more occasions of extreme summer weather conditions will put more of us at risk, particularly seniors and children without adequate supervision.