Q: What’s the best way to replace one weekly run with a gym workout?
A: Do a circuit routine that moves from exercise to exercise without rest. This will keep your heart-rate elevated while strengthening your running-specific muscles for better speed, efficiency and flexibility. Do three or four sets of the following sequence: one to three minutes of jumping rope; 10 to 12 reps of single-arm, bent-over rows with a 5- to 20-kilogram dumbbell; 12 to 15 lying leg curls; 10 push-up-to-bird-dogs (between each push-up, lift opposite arm and leg); and 10 reps – per leg – of lunge jumps (remain in one spot, spring upright to switch legs, land in lunge position).

– NANCY BURNHAM is a coach and personal trainer

Q: I don’t like hill repeats. Can I run a hilly course instead?
A: Yes. As you ascend each incline, surge for 60 to 90 seconds at about 5K race pace, or a speed at which it’s uncomfortable to talk. Return to a very easy pace – even if you haven’t crested the hill – and remain at this slow speed on the downhills and flats so you can recover. If it’s been a while since your last hill workout, start with four to six climbs. As you grow stronger, power up 10 to 12 climbs. The hilly portions of the run should total 15 to 45 minutes, depending on your ability.

– IAN TORRENCE has won 50 ultramarathons and is a running coach

Q: If I have time for only one run during the week, should I run it all-out?
A: Save “all-out” efforts for your races. If you can squeeze in only a single weekday run, it should be somewhat fun. You don’t want to make it so hard that it blows your motivation for doing more challenging runs on the weekends. To inject a little speed, try a fartlek – that is, doing short bursts of speed throughout your run. You determine how long and how hard each effort is, based on how you feel. Though short, these bursts will help build your speed and get your legs accustomed to a quicker turnover.

– EMILY WILSON is a running coach

Runner's World is the largest running magazine in the world, published monthly in 11 countries. With expert analysis from professional athletes and coaches, Runner’s World is a complete resource for runners, covering training techniques and equipment, events and the latest news, nutrition, motivation, health issues and much more.