Why this matters now
The late-summer hard-court swing has been brutally hot. Organizers activated enhanced heat measures. Players used ice towels, shade, and extended cool-down access between sets. Medical timeouts for heat stress spiked. Performance guidance emphasized sweat-rate testing and sodium replacement. Perfect timing to turn pro tools into amateur-friendly actions.
I coach in these conditions. I have cooked on DecoTurf courts that feel like radiators. The players who survive heat do two things well. They prepare their physiology. They manage the 25 and 90 second windows to keep the engine cool. This playbook shows you how to do both with simple court tests and progressions you can run this week.
Principle: Heat does not care about willpower. It rewards preparation, pacing, and cooling.
What really matters in heat
- Thermoregulation 101: You make heat when you move. You dump heat by sweating and moving air over skin. On hard courts, radiant heat from the surface increases the load. When sweat and airflow are not enough, core temp rises and performance falls.
- Sweat rate and sodium: Players vary widely. Some lose 0.5 L per hour. Others lose 2.0 L per hour. Sodium loss ranges from light to very salty. Guessing fails on a 2-hour match.
- Clock usage: Between points you get about 15 to 20 seconds of practical time. On changeovers you get 90 seconds. Build routines that fit.
- Movement economy: Shorter strides, cleaner stops, and better split timing reduce wasted heat. Think marathon form on a hot day. Smooth over fast.
Your field kit
- Bathroom scale that reads to 0.1 lb or 0.05 kg
- 1 towel for sweat collection and an ice towel on court if allowed
- 1 to 2 chilled bottles with measured volume markings
- Electrolyte mix with known sodium per serving
- Stopwatch or phone timer
- HR strap or watch. If not, use RPE 1 to 10 scale
- Light-color cap or visor, cooling sleeves, two pairs of wristbands
- OffCourt log to record numbers and build your two-week heat plan
Test 1: 20-minute sweat-rate test you can run today
This is the simplest accurate field test I use with players.
Set-up
- Do it in warm sun if safe. Pick a time near your typical match time
- Wear match kit and shoes. Use your game-day hat and sleeves if you wear them
- Bring a chilled bottle with known volume. 600 ml is convenient
- Empty bladder just before the test
Protocol
- Weigh in before exercise, wearing dry clothes. Record pre-weight.
- Warm up for 5 minutes at easy intensity. Light rally or jogging.
- Start the 20-minute session. Alternate 2 minutes rally pace and 1 minute court movement:
- 2 minutes crosscourt rally at moderate intensity
- 1 minute line shuttles service line to baseline at game intensity
- Repeat for 6 cycles total
- Drink ad lib. Note how much you drink from the marked bottle. Do not pour water on head for this test
- Towel off sweat quickly at 20 minutes and weigh immediately in the same clothes. Record post-weight
- Record any urine during the test. Ideally zero
Calculation
- Body mass change (kg) = Pre-weight minus Post-weight
- Fluid consumed (L) = Volume you drank in liters
- Urine during test (L) = likely zero
- Total fluid loss in 20 min (L) = Body mass change + Fluid consumed − Urine
- Sweat rate per hour (L/h) = Total fluid loss × 3
Example: Pre 72.6 kg, Post 72.0 kg, Drank 0.30 L, No urine
- Body mass change = 0.6 kg
- Total loss = 0.6 + 0.30 = 0.90 L in 20 min
- Sweat rate = 0.90 × 3 = 2.7 L/h
Coach note: Values from 0.6 to 2.0 L/h are common. 2.7 L/h is high but I have seen it in juniors on hot courts.
Convert to per-changeover targets
- Practical changeovers per hour average 4 to 5 in league play
- Hourly fluid target = 60 to 80 percent of sweat rate. Going for 100 percent can bloat stomach
- Per-changeover target = Hourly fluid target ÷ 4.5
Using the example above:
- 60 to 80 percent of 2.7 L/h = 1.6 to 2.2 L/h
- Per-changeover target ≈ 1.6 to 2.2 L ÷ 4.5 = 350 to 490 ml
Round to an actionable number: 400 ml each changeover. Split it in two sips to fit your routine.
Sodium ladder
- Start at 300 mg sodium per hour for light sweaters
- Medium 500 mg per hour
- Heavy and salty 700 mg per hour or more
Tie sodium to your sweat rate and taste. If your hat salt-crusts and you cramp often, start at 700 mg per hour. Use a mix with labeled sodium so math is clean. In OffCourt, save your test and attach your sodium plan.
Safety: If you have a medical condition or take medications, clear sodium strategies with your clinician.
Drill 1: Heat-tolerance shuttles with 2:1 work to rest
The goal is to train your body to shed heat while keeping movement quality. We develop the ability to recover within the clock.
Court set-up
- Place cones on service line intersections
- You will shuttle: baseline center to deuce service line, back to baseline center, to ad service line, back
- Each work interval lasts 30 seconds
Protocol
- Set 1: 6 reps of 30 seconds work, 15 seconds rest. Total 6 minutes 45 seconds
- Rest 2 minutes in shade
- Set 2: repeat 6×30 on, 15 off
- Optional Set 3 for advanced: same. Max total work 9 minutes
Cues
- Small steps into the turn. Nose over toes
- Quiet torso. Arms pump low and compact
- Land soft. Think marathon cadence. Smooth, not choppy
Intensity
- Target RPE 7 to 8 of 10 by the last two reps
- If using HR, cap at 90 percent of HRmax
Recovery test inside the drill
At the end of each set, stand in shade. Track HR 10 seconds after stop and at 60 seconds. You want a 30+ bpm drop by 60 seconds.
- If HR drop is less than 20 bpm or you feel dizzy, stop the session
- If you hit the target drop and your form stayed clean, progress next time by adding 1 rep per set or lowering rest to 12 seconds
Frequency
- 1 to 2 times per week during heat-acclimation block
- 1 time per week during competition weeks
Pro tip: I like players to put the shuttles before live points. It raises core temp and gives a real test of the between-point routine under heat.
Drill 2: Between-point cooling you can execute inside 25 seconds
You have about 15 to 20 seconds of practical time. Build a routine that actually lowers perceived heat and settles breathing.
The 4-step micro routine
- Post-contact posture: Turn away, walk tall, shoulders down. Release the exhale through nose
- Nasal breathing 6-2: 6 count inhale, 2 count exhale, 3 to 4 cycles as you walk to the baseline
- Tactile wipe: Wristband swipe across forehead and cheeks. This clears sweat to improve evaporation
- Cue word and plan: One word for body, one line for tactic. Example: Loose. Body serve plus forehand middle
This takes 12 to 16 seconds. Practice with a timer until it fits.
Changeover cool-down, 60 to 75 seconds of action
- Sit in shade. Ice towel on neck and cheeks for 20 to 30 seconds
- Sip your per-changeover target in two parts. Example: 250 ml, then 150 ml
- Nasal 6-2 breathing for 5 cycles. In through the nose, out through the nose
- Visual scan feet to head for relaxation. Release jaw and hands. Change wristbands if soaked
- Stand at 15 seconds remaining. Two quick shadow swings. Reset posture
Field note: Ice on the neck and cheeks drops skin temperature fast. It feels like confidence.
Drill 3: Gear and string heat hacks in 10 minutes
These are small, high return actions that players overlook.
- Light-color cap or visor reduces radiant heat. Wet it at changeovers if allowed
- Cooling sleeves keep sun off skin and promote evaporative cooling when damp
- Two pairs of wristbands. Swap at every changeover. Dry skin evaporates better
- Sunscreen 30+ that does not block sweat evaporation. Test in practice
- String tension: If balls feel lively and fly, go up 1 to 2 lbs. If the court is sticky and balls feel mushy, drop 1 to 2 lbs. Bring two rackets at different tensions and A/B test in the warm-up
30-ball depth A/B test
- 15 rally balls with racket A. Record how many land deep third without sailing long
- 15 rally balls with racket B. Same scoring
- Choose the setup with tighter depth dispersion in heat
Log all choices in your OffCourt gear notes with temperature and ball type.
Fueling for hot hard-court matches
- Pre-match: 2 to 3 hours out, eat a carb dominant meal with some protein. Add 500 to 600 ml fluid with 300 to 500 mg sodium
- 15 minutes out: 200 ml fluid and a small carb bite if you need it
- In-play: Hit your per-changeover fluid target. Keep sodium on the ladder you chose. If matches exceed 90 minutes, consider 20 to 30 g carbs per hour from a mix you tolerate
- Post-match: 1 to 1.5 L fluid per kg lost over the next 2 to 4 hours with sodium. Spread it out
Cramp note: Most heat cramps in tennis are multifactorial. Sodium, total fluid, and pacing all matter. Start with your sweat-rate data before buying more supplements.
Tactics that save watts in heat
- Serve patterns: Use higher first-serve percentage targets. Aim bigger to big targets. Play the body serve more to shorten the next ball
- Return intent: Deep middle on hot days is underrated. Force an extra ball without sprinting side to side
- Rally patterns: Rally tolerance goes down in heat. Pre-plan 2 to 3 patterns that move the ball without moving you too much. Think heavy crosscourt, then change up the line only on a sitter
- Movement economy: Over-split is costly. Time the split to ball-bounce on your side, not earlier. Fewer false steps. Save springs for defense
- Clock management: Use the full 25 seconds when you need it. It is a legal resource
I tell players to run a heat game plan like a negative-split run. Start controlled. Keep room to finish strong.
Two-week heat-acclimation microcycle
Goal: Build tolerance, tune routines, and validate sweat-rate targets before tournament weekend.
Week 1
- Mon: On-court 75 minutes at late-afternoon heat
- Warm-up 10 min
- Heat-tolerance shuttles 2 sets of 6×30 on, 15 off. 2 min set rest
- Live crosscourt 2×8 min at RPE 6. 2 min rest
- Between-point micro routine on every rally
- Changeovers at 10 min intervals. Use per-changeover fluid
- Tue: Easy aerobic 30 min in heat. Light mobility 15 min. Sodium 300 to 500 mg per hour
- Wed: On-court 90 minutes match play
- Warm-up 10 min
- Practice set with full changeover routine. Track fluid
- Simple Test A: Recovery to Serve (see below)
- Thu: Off or pool flush 20 min
- Fri: On-court 60 minutes skill plus heat shuttles
- Serve plus 1 patterns 30 min
- Heat-tolerance shuttles 2 sets of 5×30 on, 15 off
- Sat: Match play 2 hours if safe. Use sodium ladder
- Sun: Off and review. Adjust per-changeover targets if you under or over drank
Week 2
- Mon: On-court 75 minutes with pace stress
- Warm-up 10 min
- Heat shuttles 3 sets of 5×30 on, 12 off
- Point play to 15 with serve clock awareness
- Tue: Easy aerobic 30 min + breathing practice 5 min nasal 6-2
- Wed: On-court 90 minutes practice set
- Simple Test B: Repeat sweat-rate test if the forecast is hotter than last week
- Thu: Off or mobility 20 min
- Fri: Pre-tournament tune 60 minutes
- 20 min live hitting at RPE 5
- 20 min serve plus 1
- 10 min between-point routine rehearsal with timer
- 10 min gear A/B test if needed
- Sat-Sun: Tournament
- Use checklists and fluid targets. Adjust for actual sun and wind
Record every session in your OffCourt plan so you can see patterns across heat exposures.
Simple field tests to confirm readiness
1) Recovery to Serve test
- After a 16-ball live rally drill, walk to baseline and start your serve routine
- You pass if you can begin serve toss by second 18 to 20 while nasal breathing stays smooth and HR is under 120 to 130 bpm
- If you fail twice in a row, your between-point routine is not yet automatic. Practice it with a timer for 10 minutes at the end of practice
2) HR Drop test on a hot day
- After a 2-minute intense rally block, sit in shade for changeover
- HR should drop 30+ bpm by the 60-second mark with ice towel on neck and cheeks
- If not, reduce intensity next block and increase airflow with a fan if available. Validate sodium and fluid plan
3) Scale check post session
- Immediate post-practice weigh-in. If you lost more than 2 percent of body mass, you under-consumed. Increase per-changeover fluid by 50 to 100 ml next session
Putting it all together on match day
- Warm-up in shade and finish with 1 to 2 minutes of heat shuttles to prime sweat
- Confirm per-changeover fluid and sodium amounts. Pre-open packets and mark bottle lines
- Place ice towel in cooler. Two pairs of wristbands ready
- Use the micro routine after every point. When in doubt, slow your walk and lengthen the exhale
- On changeovers, sit, cool, sip, breathe, reset. Get up with 15 seconds left
- If you feel chills, dizziness, confusion, or stop sweating, stop and seek help. Heat illness escalates fast
Most players win more points by managing heat than forcing winners in the second set.
Frequently asked questions
- What if I cannot stomach 400 ml per changeover? Start at 250 ml. Use cooler fluids. Practice in training until your gut adapts
- Do I need a fancy electrolyte? No. You need known sodium content. Pick a flavor you like and stick to it
- Can I pour water on my head? Yes, if allowed. Do not replace drinking with pouring. Use both
- Is nasal 6-2 right for everyone? If you feel air hunger, shorten to 4-2. The goal is calm, not a specific count
- How fast can I acclimate? Most players see benefits in 5 to 7 heat exposures across 10 to 14 days
OffCourt tracking cues
- Save your sweat-rate number and note the temperature, wind, and sun
- Set per-changeover targets in your match plan. Use a simple checkbox each changeover
- Attach the Heat Tolerance Shuttles drill to two sessions per week. Log HR drops
- Tag gear and string choices to temperature bands. Include ball type
Quick checklist
- Sweat-rate tested and logged with per-changeover target
- Sodium ladder chosen. Pack enough for match length
- Cooling kit: ice towel, two wristband pairs, light cap, sleeves
- Between-point routine rehearsed with timer. Fits the clock
- Heat-tolerance shuttles completed twice in the last 10 days
- Two rackets strung with a 1 to 2 lb spread for heat
Next steps on court this week
- Day 1: Run the 20-minute sweat-rate test and set your changeover target
- Day 2: 2 sets of Heat Tolerance Shuttles, then 30 minutes of point play using the micro routine
- Day 3: Practice set. Use full changeover cool-down. Log HR drops and fluid
- Day 4: Tune string choice with the 30-ball A/B test. Finalize gear
Heat is a solvable problem. Treat it like any other performance variable. Test, adapt, and practice until the routine is automatic. When the court feels like a skillet, you will still have legs and a plan.