Mariposas
Best Cardio Exercises
By Zachary, builder of Mariposas · Reviewed against published exercise-science sources (references)
· Last updated June 2026
Cardio training has a reputation problem. People either treat it as punishment after lifting or assume more minutes automatically means better fitness. Neither is true. The exercises that actually move the needle share a common trait: they demand enough output that your cardiovascular system has to adapt, not just survive. If you want to track which sessions are genuinely pushing your aerobic capacity versus which ones are just burning time, logging your workouts free in Mariposas lets you collect pets along the way and build a real picture of your progress.
How to train your cardio
Most people who train cardio effectively mix intensities across the week rather than grinding the same moderate pace every session. Lower-intensity steady-state work builds aerobic base and aids recovery, while higher-intensity intervals stress the system in ways that produce faster adaptation in VO2 max and cardiac output. Volume and frequency depend heavily on what else is in the training week, since cardio and strength work compete for recovery resources. Many coaches program two to four cardio sessions weekly, varying the format so the body doesn't fully adapt to one stimulus.
FAQ
- What actually makes one cardio exercise better than another?
- The honest answer is that the best cardio exercise is mostly the one you'll do consistently and push hard enough to matter. That said, there are real differences in how exercises stress your system. Rowing and cycling are low-impact, which means joint stress doesn't cap your intensity the way it can in running. Exercises that involve large muscle mass, like rowing or cross-country skiing, tend to drive heart rate higher because more tissue is demanding oxygen at once. If your goal is pure aerobic capacity, higher muscle recruitment is an advantage.
- How long does it actually take to see cardiovascular improvements?
- Most people notice meaningful changes in resting heart rate and perceived exertion within three to six weeks of consistent training. VO2 max improvements, which are a better marker of true fitness, typically show up in studies after six to eight weeks of regular effort. The catch is that 'consistent' means sessions where you're actually working, not just moving. A few uncommitted sessions per week will produce minimal adaptation. The cardiovascular system responds to demand, and it has to perceive the demand as a challenge worth adapting to.
- Is it better to do cardio before or after lifting?
- The order matters more for performance in the session than for long-term outcomes. Doing intense cardio before heavy strength work tends to blunt force production and coordination for the lifts, because glycogen is partially depleted and the nervous system is pre-fatigued. Most strength-focused athletes do cardio after lifting, or on separate days entirely. If fat loss or general conditioning is the priority rather than maximal strength, the order becomes less critical. Some research does suggest that the 'interference effect,' where concurrent training limits strength gains, is real but modest when cardio volume is kept reasonable.
- Why does steady-state cardio feel harder some days for no obvious reason?
- A few factors are genuinely responsible for this. Sleep quality is the biggest one that people underestimate. Even one night of poor sleep meaningfully increases perceived exertion at a given pace or intensity. Hydration status affects blood viscosity and heart rate, so being slightly dehydrated makes the heart work harder to move the same volume of blood. Accumulated training stress, called residual fatigue, also builds across a week and makes Friday's session feel worse than Monday's even at identical intensity. Tracking your sessions over time helps distinguish a bad-day pattern from a genuine fitness plateau.