High-impact activities are exercises where both feet leave the ground at some point during the movement, generating force through your skeleton when you land. Running, jumping, skipping rope, and most court sports all qualify. What makes them “high impact” is the ground reaction force they produce: while walking generates roughly 1.0 to 1.5 times your body weight in force with each step, running produces 2.0 to 2.9 times your body weight, and jumping can exceed four times your body weight.
What Counts as High Impact
The defining feature is repeated loading through your joints and bones at forces well above what you experience standing or walking. Any activity involving running, hopping, bounding, or landing from a jump fits the category. Common examples include:
- Running and sprinting at any speed, from jogging to racing
- Jump rope, particularly at fast paces of 120 to 160 skips per minute
- Basketball, soccer, and tennis, which combine running with sudden direction changes
- Plyometric training like box jumps, burpees, and jump squats
- High-impact aerobics and dance cardio with jumping movements
- Martial arts such as kickboxing, taekwondo, and judo
- Squash and racquetball, which involve explosive lateral movement
By contrast, low-impact activities keep at least one foot on the ground (walking, hiking) or remove ground contact forces entirely (swimming, cycling). The distinction isn’t about intensity or how hard you breathe. You can do a brutally hard cycling workout that’s still low impact, or a light jog that’s technically high impact.
Why High Impact Matters for Your Bones
The biggest unique benefit of high-impact exercise is its effect on bone density. Your skeleton responds to mechanical stress by building itself stronger, a principle known as the Mechanostat theory. When high forces travel through bone during landing and push-off, the cells embedded in bone tissue detect that strain and trigger a cascade of biochemical signals that stimulate new bone formation. Over time, this thickens both the dense outer shell of bone and the spongy interior lattice, making the entire structure more resistant to fracture.
The threshold for triggering this bone-building response appears to be a ground reaction force of at least two times your body weight, which is right in the range that running naturally produces. Higher-force activities like jumping deliver an even stronger stimulus. A six-month jump rope program in postmenopausal women improved lumbar spine bone density and reduced the rate of bone loss. This makes high-impact exercise particularly valuable during the decades when bone density peaks (teens through the 30s) and again after menopause, when bone loss accelerates.
Low-impact and water-based exercises can also support bone health when they involve strong muscular contractions, but they generally produce a weaker osteogenic signal than activities with direct skeletal loading.
Calorie Burn and Cardiovascular Fitness
High-impact activities tend to burn more calories per minute than their low-impact counterparts, largely because launching your body off the ground and absorbing the landing requires significant energy. Running stairs, for instance, registers at roughly 15 METs (a standard measure of energy expenditure), while fast-paced jump rope and fast running both land around 12 METs. Martial arts at a moderate pace come in around 10 METs. For comparison, brisk walking sits around 4 to 5 METs.
Beyond the raw calorie numbers, the repeated high-force muscle contractions in these activities drive cardiovascular adaptation efficiently. Your heart has to pump harder to supply working muscles during explosive movements, which builds aerobic capacity and improves how well your body uses oxygen over time.
Joint Health: What the Evidence Shows
A common concern is that high-impact exercise wears out your joints, but the research paints a more reassuring picture for people with healthy knees and hips. Strenuous exercise on normal joints does not appear to substantially increase the risk of osteoarthritis. Studies tracking runners over many years have found they develop less disability, seek medical attention less frequently, and maintain higher functional capacity than non-runners of the same age. One comparison of athletes and over 900 controls found slightly more radiographic signs of osteoarthritis in athletes’ joints, but the athletes actually reported fewer symptoms.
The real risk factor isn’t impact itself but injury. Knee injuries carry a fivefold increased risk of later osteoarthritis, which helps explain why soccer players (29% prevalence of osteoarthritis signs in one study) have much higher rates than runners (14%). Soccer’s combination of collisions, tackles, and ligament tears does far more cartilage damage than the repetitive, predictable loading of running. Excess body weight also contributes: weightlifters in the same study showed 31% prevalence, likely related to the heavy loads their joints carried.
The takeaway is that high-impact activity is generally safe for healthy joints, but protecting yourself from acute injuries through proper form, adequate rest, and appropriate progression matters enormously for long-term joint health.
Pelvic Floor Considerations
One underappreciated effect of high-impact exercise is the strain it places on the pelvic floor. Jumping, sprinting, and rapid direction changes all push downward on pelvic floor muscles, and for some people this leads to symptoms like urine leakage during activity. A study of 325 athletes at the 2024 World Athletics U20 Championships found that nearly 13% reported urinary incontinence triggered by athletic movements. Females were disproportionately affected, with over half (53.7%) reporting some form of pelvic floor symptoms compared to 29.3% of males.
This doesn’t mean high-impact activities should be avoided, but it does mean that pelvic floor strength is worth building alongside everything else. Targeted pelvic floor exercises can reduce or eliminate leakage for most people who experience it.
How Your Body Adapts to Impact
If you’re new to high-impact exercise, your muscles will adapt faster than the rest of your body. Tendons, the tough cords connecting muscle to bone, remodel more slowly. Research on tendon adaptation found that 14 weeks of training increased tendon stiffness by 65%, while muscle volume and force increased only 6% and 11% over the same period. This mismatch matters: tendons need time to catch up to what your muscles can handle.
This is why gradual progression is so important when starting or returning to high-impact activities. Jumping straight into daily running or intense plyometrics before your connective tissue has adapted is a common path to tendon pain and overuse injuries. A reasonable approach is to increase volume or intensity by no more than about 10% per week, and to alternate high-impact days with lower-impact recovery sessions.
High Impact for Older Adults
Older adults stand to gain significant benefits from impact loading, particularly for bone density and fall prevention, but the approach needs to be scaled appropriately. The National Institute on Aging identifies aerobic exercise, muscle strengthening, and balance training as beneficial for older adults, with bone and muscle health being especially important for reducing fall risk.
Modified high-impact activities for older adults might include low-height hops, heel drops (rising onto the toes and dropping back onto the heels), brisk walking with added resistance, or light jogging on forgiving surfaces. Even small amounts of impact, if the ground reaction force reaches that two-times-body-weight threshold, can provide a meaningful bone-building stimulus. The key is matching the intensity to the person’s current fitness level, joint health, and balance confidence rather than avoiding impact altogether.