Add load to your routine- that is one of the simplest and most effective ways you can increase stability/strength of the muscles, joints and bones, increase your heart rate and release those happy hormones. There is a direct correlation between strength (body AND mind) and overall happiness, start now!!
Difficulty: graded by weight.
Equipment: Choose an appropriately heavy object- kettlebell, 2 barbells, laundry detergent container, weighted ball, gallon water