What Vaping Is Really Doing to Your Lungs (and Your Heart)
Walk anywhere, and you’ll see it—vapes everywhere. Sleek, discreet, and widely accepted, they’ve become part of the modern landscape, often framed as a cleaner, safer alternative to smoking.
Posts by:
Maria Stevens, MD - Director of Fitness & Education
Dr. Stevens has been a Certified Personal Trainer through the American Council on Exercise since 2007 and has pursued additional training in corrective exercise, yoga, medical fitness, and metabolic health. Her work reflects a long-standing interest in plant-based nutrition, therapeutic stretching, and hands-on approaches to movement and recovery. She has a background in elite endurance sports and mixed martial arts, and has spent many years training and coaching across a wide range of athletic and clinical settings.
Physical Activity Is Preventive Medicine — But Access Still Matters
Every May, during National Physical Fitness and Sports Month, there is renewed public conversation about exercise, health, and longevity. That conversation matters, because the United States continues to face rising rates of obesity, metabolic disease, chronic pain, cardiovascular disease, depression, and loss of functional independence. Yet despite overwhelming evidence supporting physical activity as one of the most effective forms of preventive healthcare ever studied, structured exercise remains financially and logistically inaccessible for many Americans.
Why Fat Tissue Becomes “Oxygen-Starved”—And Why It Matters for Your Health
Most people think of body fat as passive storage—just extra calories sitting around.
Kyphosis, Posture, and the Cost of Living Bent Forward
Stand up for a moment and take a breath.
Alcohol and Sleep: Why the Nightcap Works… Until It Doesn’t
A lot of smart, disciplined people swear they sleep better after a drink.
Iron, Oxygen, and the Edge Between Performance and Damage
At FITNESS SF, we talk about progressive overload, VO₂ max, strength adaptation, and recovery. This discussion is based on a 2023 systematic review examining how iron levels influence physical performance in athletes.
How Exercise Prevents Frailty and Fragility Fractures
Aging changes the body — but decline is not inevitable.
Why Sleep Protects Your Memory, Focus, and Long-Term Health
When most people think about sleep, they think about energy. They think about not feeling tired at work, having enough motivation to exercise, or avoiding that mid-afternoon crash. But modern neuroscience shows us something much more important: sleep is not just about feeling rested. It is one of the most powerful tools we have for protecting the long-term health of our brains.
Cold Water, Old Wisdom: Why Cold Exposure Is Having a Moment (Again)
Cold-water exposure may feel like a modern wellness trend, but it’s anything but new. Long before ice baths showed up on social media, cold water was woven into health practices across cultures. Ancient Greeks prescribed cold baths for vitality. Nordic countries paired cold plunges with saunas for resilience and recovery. In Japan, cold-water immersion has long been part of physical and spiritual discipline. Even early Western medicine viewed cold exposure as a way to sharpen the mind and strengthen the body.
Cardio vs Weights vs Both: What Actually Works Best for Fat Loss?
If you hang around our gyms long enough, you’ll hear some version of this debate in every locker room:
“If I want to lose fat, should I just do cardio?”
“But I heard lifting is better because it boosts your metabolism.”
“What if I do both—will they cancel each other out?”
A 2025 systematic review and meta-analysis (36 randomized trials, 1,564 adults) just took a hard look at this exact question: comparing aerobic training (cardio), resistance training (strength), and concurrent training (both in the same week) and how each affects body fat, body weight, and muscle mass (PubMed). Here’s what it means for you at FITNESS SF.