Strength training promotes the growth of new brain cells, boosts memory and blood flow to the brain. 

After age 35, muscle tissue naturally decreases 1-2% per year, then accelerates after menopause, and can lead to 3% lost annually by age 60. Decreased muscle mass can lead to loss of mobility, function and independence, and may increase the risk of heart disease or stroke. Strength training fights muscle loss. 

Strong bones enable movement, good posture and reduce the chance of debilitating falls. Bone mass peaks at age 30. When we lift, muscles tug on bones, stimulating them to bulk up. Strength training is key to maintaining bone mass as we age. 

Muscle burns more calories at rest than fat. Increasing muscle drives up your resting metabolism, as much as 4% in women and 9% in men. In the hours following a workout, muscles continue to burn more calories.

Strength training can reduce stress by releasing endorphins, the feel good hormones, and lowering cortisol, the stress hormone. Studies show strength training can reduce anxiety by up to 20%. In addition to hormonal health, strength training boosts confidence and provides a sense of mastery and grit. 

Resistance training causes muscle fatigue which can contribute to delayed-onset muscle soreness and sleep-inducing relaxation even hours after a workout. Lifting weights also stimulates the body to produce adenosine, the chemical that manages our sleep-wakefulness cycle.